Feedback from Gen 2 engine failures
Discussion
Just to make a plea for anyone with experience of a Gen 2 bore scoring failure to assist our research by contacting us.
We have now received a damaged car, engine parts and feed back from a few UK based specialists that has been extremely helpful (thank you guys!). We have measured all the parts and analysed the failure causes with 3.8 Gen 2 engines.
At this stage we don't know how many are likely to be affected - probably less numbers than Gen 1 and probably at higher mileages.
What makes it difficult to assess is the small numbers - yet we hear of a lot more engines being replaced (rather like the early stages of Gen 1 problems).
The Gen 1 was relatively easy to analyse - weaker thin cylinder material with larger forces on it leading to cracking, changes to piston coatings being less resistant to wear, a bearing system that was often inadequate.
The Gen 2 is far better made - should be almost bullet proof - yet there seems to be one technical area of concern.
Problems that relate in some way to the number of complete thermal cycles the engine goes through (probably regardless of mileage) and impossible for manufacturers to reproduce since it require a full heat to fully cold cycle to be reproduced "x" number of times with a lot of sample vehicles - so if and when it occurs - it is often too late to alter the production or find a sensible solution for from them.
It would help me enormously - not so much to find the cause (as I am certain I understand that) but work out the numbers and predict the ages and mileages if anyone who has had any experience of a failure World-Wide - would send me the following information.
(1) Where did the piston score (one side or both sides and in the centre of the piston thrust face or either side?).
(2) What age was the car?
(3) What mileage di it occur at?
(4) Which bank did it occur on?
(5) which cylinder failed?
(6) What capacity was it?
This request is absolutely not scare mongering nor seeking business - because we are going to provide a solution in any case as we believe there will be a small but steady stream of similar failures over time. We are also working at capacity anyway and numbers of M96/7 Gen 1 engines are not diminishing.
It would help if those who cannot wait to deflect my simple request and turn it into some other issue kindly leave this particular post for serious and reliable answers - they will not make any car score a bore - but they will help speed up the provision of a solution and minimise the cost for anyone who does experience it - however few that will turn out to be.
Thanks,
Baz
We have now received a damaged car, engine parts and feed back from a few UK based specialists that has been extremely helpful (thank you guys!). We have measured all the parts and analysed the failure causes with 3.8 Gen 2 engines.
At this stage we don't know how many are likely to be affected - probably less numbers than Gen 1 and probably at higher mileages.
What makes it difficult to assess is the small numbers - yet we hear of a lot more engines being replaced (rather like the early stages of Gen 1 problems).
The Gen 1 was relatively easy to analyse - weaker thin cylinder material with larger forces on it leading to cracking, changes to piston coatings being less resistant to wear, a bearing system that was often inadequate.
The Gen 2 is far better made - should be almost bullet proof - yet there seems to be one technical area of concern.
Problems that relate in some way to the number of complete thermal cycles the engine goes through (probably regardless of mileage) and impossible for manufacturers to reproduce since it require a full heat to fully cold cycle to be reproduced "x" number of times with a lot of sample vehicles - so if and when it occurs - it is often too late to alter the production or find a sensible solution for from them.
It would help me enormously - not so much to find the cause (as I am certain I understand that) but work out the numbers and predict the ages and mileages if anyone who has had any experience of a failure World-Wide - would send me the following information.
(1) Where did the piston score (one side or both sides and in the centre of the piston thrust face or either side?).
(2) What age was the car?
(3) What mileage di it occur at?
(4) Which bank did it occur on?
(5) which cylinder failed?
(6) What capacity was it?
This request is absolutely not scare mongering nor seeking business - because we are going to provide a solution in any case as we believe there will be a small but steady stream of similar failures over time. We are also working at capacity anyway and numbers of M96/7 Gen 1 engines are not diminishing.
It would help if those who cannot wait to deflect my simple request and turn it into some other issue kindly leave this particular post for serious and reliable answers - they will not make any car score a bore - but they will help speed up the provision of a solution and minimise the cost for anyone who does experience it - however few that will turn out to be.
Thanks,
Baz
Edited by hartech on Sunday 5th February 11:59
Well I have contacted everyone that had reported a problem somewhere - please be positive - help me and tell me how better to obtain data than on an International Porsche forum?
If it were not for data and specialist trying to provide for an anticipated demand there would have been no LTT's, none of the huge number of IMS solutions, more expensive suspension replacements, no scored bore and cracked cylinder solutions and more owners paying out far more for a solution that they already realise is flawed. There would also be no advice and more engines failing sooner.
Whether or not Porsche collect data there is little evidence they do anything about it to help those experiencing the consequences and anyway would they share it?
It is really difficult to work out what the causes are early on with limited evidence to establish a reliable correlation. Unless people intend to be purposely provocative what is wrong with asking those that had a problem to contribute towards a solution -- after all those that have not have nothing useful to add.
Baz
If it were not for data and specialist trying to provide for an anticipated demand there would have been no LTT's, none of the huge number of IMS solutions, more expensive suspension replacements, no scored bore and cracked cylinder solutions and more owners paying out far more for a solution that they already realise is flawed. There would also be no advice and more engines failing sooner.
Whether or not Porsche collect data there is little evidence they do anything about it to help those experiencing the consequences and anyway would they share it?
It is really difficult to work out what the causes are early on with limited evidence to establish a reliable correlation. Unless people intend to be purposely provocative what is wrong with asking those that had a problem to contribute towards a solution -- after all those that have not have nothing useful to add.
Baz
That's it Slippydiff - I could do with a PR person like you!
I absolutely agree - these Gen 2 engines are superb designs and much improved quality and I don't expect many to go wrong - however the evidence I have so far uncovered is completely consistent and all exactly the same and it implies that there is a problem that will very gradually deteriorate and eventually afflict higher mileage cars. When I measure and assess the issues the very same results show a consistent trend that makes engineering sense and explains things. What I want to establish is if it is always in the same place and at what mileages or ages we may expect it to occur (however rarely).
In view of this we have already invested in buying a good engine, now in repairing a scored engine, bought a car for ourselves to investigate and test and are trying to obtain another set of scored crankcases to compare.
When the Gen 1 cars first raised questions about failures - initially the Main Agents dealt with things and it took time to find out what the frequency was. Owners of new cars usually had the Porsche extended warranty and went there with problems and usually the second owners as well - so it took a while to feed back into our loop. When it did we had to start working out causes, developing solutions, testing them and eventually putting things into production.
While it can take too long for manufacturers to respond - even at our level - there is quite a lead time before a solution can be offered to the public.
I need to work out if it is likely to afflict all eventually or if there is something else causing just a few to fail.
The sooner I can make a decision about that the sooner I can provide a suitable solution and get it under test and put mileage on it - the sooner we will be able to respond if (as I expect) a few more come along for repair.
With the M96/7 IMS bearing, cracked cylinders and heads, crankshaft bearing failure and scored cylinders - it was relatively easy as an engineer to identify a cause and find a solution - so we were quick to respond.
These Gen 2 engines are so much better with what looks like all previous issues addressed - it is the relative rarity of failures and the gradual dissemination of causes that could delay things like before. I am just trying to make those aware of the possibilities that have a problem to think of letting me know the answers I seek to work out the likely timescale and volumes for economic production to start (and if it proves necessary or beneficial anyway).
I am already confident enough that I understand the problem to develop our first solution (which is in progress) but you can never have too much information and every little bit helps.
Baz
I absolutely agree - these Gen 2 engines are superb designs and much improved quality and I don't expect many to go wrong - however the evidence I have so far uncovered is completely consistent and all exactly the same and it implies that there is a problem that will very gradually deteriorate and eventually afflict higher mileage cars. When I measure and assess the issues the very same results show a consistent trend that makes engineering sense and explains things. What I want to establish is if it is always in the same place and at what mileages or ages we may expect it to occur (however rarely).
In view of this we have already invested in buying a good engine, now in repairing a scored engine, bought a car for ourselves to investigate and test and are trying to obtain another set of scored crankcases to compare.
When the Gen 1 cars first raised questions about failures - initially the Main Agents dealt with things and it took time to find out what the frequency was. Owners of new cars usually had the Porsche extended warranty and went there with problems and usually the second owners as well - so it took a while to feed back into our loop. When it did we had to start working out causes, developing solutions, testing them and eventually putting things into production.
While it can take too long for manufacturers to respond - even at our level - there is quite a lead time before a solution can be offered to the public.
I need to work out if it is likely to afflict all eventually or if there is something else causing just a few to fail.
The sooner I can make a decision about that the sooner I can provide a suitable solution and get it under test and put mileage on it - the sooner we will be able to respond if (as I expect) a few more come along for repair.
With the M96/7 IMS bearing, cracked cylinders and heads, crankshaft bearing failure and scored cylinders - it was relatively easy as an engineer to identify a cause and find a solution - so we were quick to respond.
These Gen 2 engines are so much better with what looks like all previous issues addressed - it is the relative rarity of failures and the gradual dissemination of causes that could delay things like before. I am just trying to make those aware of the possibilities that have a problem to think of letting me know the answers I seek to work out the likely timescale and volumes for economic production to start (and if it proves necessary or beneficial anyway).
I am already confident enough that I understand the problem to develop our first solution (which is in progress) but you can never have too much information and every little bit helps.
Baz
Thanks to those of you that support my simple invitations - which is directed only to those who have had a failure or worked on one.
This simple fact demonstrates that my post was not intended for anyone else - although I agree - anyone can comment if they have to but my intention was not and still is not for anyone else to contribute - exactly to try and avoid the type of responses that some people cannot avoid posting - which dilutes the information, confuses readers and sets up alternative correspondence nothing to do with the subject and can descend into chaos.
I have not said what I think will unfold directly - that would scare people. I have been trying very hard to avoid upsetting anyone and softening what I already know. Remember this in a few years time and remember who said what!
I have also posted the question in a largely USA forum.
This is not a fatigue problem. Fatigue is relatively easy to model (particularly with ferrous metals) and this problem is very unusual and almost quite weird. I think if it was possible to model it and predict the future expectations some simple changes would have been made.
This is exactly the problem I have (and some owners will also have) a problem that I think would have been impossible to test for, predict and deal with before production started and not experienced until some years later.
I am not prepared to state exactly what I think has happened yet (it - like many other of our research projects costs a small fortune to establish and is our intellectual property) and frankly several contributors do not deserve such open dissemination of highly technical information honestly discovered for genuine reasons - yet.
Time will tell - remember these posts!
Baz
This simple fact demonstrates that my post was not intended for anyone else - although I agree - anyone can comment if they have to but my intention was not and still is not for anyone else to contribute - exactly to try and avoid the type of responses that some people cannot avoid posting - which dilutes the information, confuses readers and sets up alternative correspondence nothing to do with the subject and can descend into chaos.
I have not said what I think will unfold directly - that would scare people. I have been trying very hard to avoid upsetting anyone and softening what I already know. Remember this in a few years time and remember who said what!
I have also posted the question in a largely USA forum.
This is not a fatigue problem. Fatigue is relatively easy to model (particularly with ferrous metals) and this problem is very unusual and almost quite weird. I think if it was possible to model it and predict the future expectations some simple changes would have been made.
This is exactly the problem I have (and some owners will also have) a problem that I think would have been impossible to test for, predict and deal with before production started and not experienced until some years later.
I am not prepared to state exactly what I think has happened yet (it - like many other of our research projects costs a small fortune to establish and is our intellectual property) and frankly several contributors do not deserve such open dissemination of highly technical information honestly discovered for genuine reasons - yet.
Time will tell - remember these posts!
Baz
A couple of additional bits of information.
When problems with the Gen 1 first came to our attention with IMS failure about 14-15 years ago) and then Cracked cylinders (a little later) - we were able to work out what the problem was after seeing and measuring the first example (it was to us so obvious - sealed off bearing losing its grease, boring out a thicker cylinder wall in a Boxster S thinner in a 3.4 996 and then pushing more power against it in relatively weak materials compared to the previous Alusil or finned air cooled Nikasil cylinders). Measuring the cylinders showed that they all gradually went increasingly oval (slightly different rates of ovality in different cylinders) but predictably once they got to 10 thou oval a crack or "D" chunk was imminent.
Rebuilds with new Nikasil plated cylinders, a LTT, revised IMS bearing etc transformed reliability.
The cause of Bore scoring was more difficult to understand quickly. It was unusual for it to be one side of the piston and only on one bank but always in the thrust direction. We analysed coolant temperatures throughout the engine, tested oil spray jets positions, clearances etc but initially imagined (as the manufacturers implied in their technical literature) that Lokasil was the same as Alusil at the piston face. It took a while to test the materials and find out it was not and then of course the change to a plastic coated piston was analysed and testing showed up that it was softer than the previous ferrous coating (especially at running temperatures). Eventually that was fully understood.
If only there was no IMS bearing, a closed deck and ferrous coated pistons - everything should have been OK = Gen 2 Hurrah!
The Gen 2 engines are very much more reliable - a massive improvement - but a very few have been reported with bore scoring but the ones we have inspected and measured (and those reported to us) all have the very same identical issue. This time a full seizure but not in the centre of the piston (rather odd). It all means they may be very much better engines but might just have one weak spot (instead of a number) and that might only afflict fewer numbers (only time will tell).
Although we have only had access to a few samples - they all exhibit an identical trend that we can measure and it even explains why a particular cylinder went first. Some cylinders are still OK while others are on their way to the same outcome (a bit similar to M96/7 cylinder cracking).
So however rare this problem is going to become – it will definitely afflict some more engines and will be to some extent a time based issue (not expected in the first few years). Until it occurs I don’t expect there to be any warning signs (smoke and increased oil consumption) and when it does I don’t expect it to be slow to deteriorate (like M96/7 bore scoring) but needing immediate attention. Unless there have been changes to the design meanwhile – replacement cylinder blocks could be expected to exhibit the same ageing.
We will have an alternative repair available for those that need it (however few that turns out to be).
As the subject of the economics of different models has also reached this post – there is (I think) a very good argument for rebuilding an M96/7 engine compared to moving up to a Gen 2.
If the reason to consider a move to Gen 2 is awareness of mileages creeping up in a M96/7 and the owner otherwise would have kept their present car longer – they have probably already paid for it and face a reduction of P/ex dealer margin on its value and a large additional spend to obtain a similar but newer Gen 2 car – which I think would be at least £12 to £15K (if it is one of the first Gen 2’s) probably more if an even newer and lower mileage car is sought. The replacement car will already have miles on it and after a few more years there is then a chance that that newer car will need engine attention one day.
I agree with Science Teacher - the old 996's were a great drive but of course a turbo has this alloy Nikasil cylinders!
Instead – a reliable rebuild of an M96/7 - for similar or less money – that combines a trusted warranty provides just as good (if not better) future lifespan.
“What about depreciation” I hear you say. Well all Porsches go through a similar curve and have for years, First rapid then a lift after about 4 years to 6 years, then steady depreciation ending with a long period static and finally a continual rise to very high levels. So the Gen 2 will continue to depreciate whereas most M96/7 cars have already reached that levelling out phase in Porsche depreciation and will start rising in value in the years ahead (especially with a reliable engine rebuild already completed).
Add in that financial picture and the Gen 1 comes out massively on top.
“What about the increased Gen 2 performance” I hear – well we are addressing that too for those that want it with capacity upgrades to all models 3.2 and above (for little more cost).
Sorry cannot do anything about PDK though (but not everyone likes it I hear).
With all the advice about how to extend the life of Gen 1 (LTT, thorough warming up, thicker oils, avoiding fast 2nd gear take off in a tip) now everyone’s mileage is increasing - the most common failure is just beginning to shift to include crankshaft bearing failure – that does make a rebuild after crankshaft failure much more expensive as it often not only needs a new crankshaft but usually snaps the rod and scraps the crankcases and pistons if not heads etc. So we think the merits of a preemtive rebuild are looking stronger and the economics of it are very well justified.
I don’t really want to add to the present argument about scaremongering but I guess accusations abounded at the start of the M96/7 saga (lots of IMS arguments “surely Porsche know best” etc – but led to worthwhile alternatives and I guess in 1938/9 there was plenty in that category that also turned out to be true. Surely it is only if the information greatly exaggerates the position that it can be criticised but if a scary situation exists – reporting it accurately may well scare people (you could refer to it rightly as “scary information” but at least prepares them to seek alternatives and is almost always better than not knowing the inevitable and being unable to do anything about it or make appropriate choices as a result? In my view “scaremongering” is doing something purely with the intention of promoting fear whereas all our work is absolutely and entirely intended to help owners and our customers reduce their fear and have viable alternatives – which is hardly the same thing!
Baz
When problems with the Gen 1 first came to our attention with IMS failure about 14-15 years ago) and then Cracked cylinders (a little later) - we were able to work out what the problem was after seeing and measuring the first example (it was to us so obvious - sealed off bearing losing its grease, boring out a thicker cylinder wall in a Boxster S thinner in a 3.4 996 and then pushing more power against it in relatively weak materials compared to the previous Alusil or finned air cooled Nikasil cylinders). Measuring the cylinders showed that they all gradually went increasingly oval (slightly different rates of ovality in different cylinders) but predictably once they got to 10 thou oval a crack or "D" chunk was imminent.
Rebuilds with new Nikasil plated cylinders, a LTT, revised IMS bearing etc transformed reliability.
The cause of Bore scoring was more difficult to understand quickly. It was unusual for it to be one side of the piston and only on one bank but always in the thrust direction. We analysed coolant temperatures throughout the engine, tested oil spray jets positions, clearances etc but initially imagined (as the manufacturers implied in their technical literature) that Lokasil was the same as Alusil at the piston face. It took a while to test the materials and find out it was not and then of course the change to a plastic coated piston was analysed and testing showed up that it was softer than the previous ferrous coating (especially at running temperatures). Eventually that was fully understood.
If only there was no IMS bearing, a closed deck and ferrous coated pistons - everything should have been OK = Gen 2 Hurrah!
The Gen 2 engines are very much more reliable - a massive improvement - but a very few have been reported with bore scoring but the ones we have inspected and measured (and those reported to us) all have the very same identical issue. This time a full seizure but not in the centre of the piston (rather odd). It all means they may be very much better engines but might just have one weak spot (instead of a number) and that might only afflict fewer numbers (only time will tell).
Although we have only had access to a few samples - they all exhibit an identical trend that we can measure and it even explains why a particular cylinder went first. Some cylinders are still OK while others are on their way to the same outcome (a bit similar to M96/7 cylinder cracking).
So however rare this problem is going to become – it will definitely afflict some more engines and will be to some extent a time based issue (not expected in the first few years). Until it occurs I don’t expect there to be any warning signs (smoke and increased oil consumption) and when it does I don’t expect it to be slow to deteriorate (like M96/7 bore scoring) but needing immediate attention. Unless there have been changes to the design meanwhile – replacement cylinder blocks could be expected to exhibit the same ageing.
We will have an alternative repair available for those that need it (however few that turns out to be).
As the subject of the economics of different models has also reached this post – there is (I think) a very good argument for rebuilding an M96/7 engine compared to moving up to a Gen 2.
If the reason to consider a move to Gen 2 is awareness of mileages creeping up in a M96/7 and the owner otherwise would have kept their present car longer – they have probably already paid for it and face a reduction of P/ex dealer margin on its value and a large additional spend to obtain a similar but newer Gen 2 car – which I think would be at least £12 to £15K (if it is one of the first Gen 2’s) probably more if an even newer and lower mileage car is sought. The replacement car will already have miles on it and after a few more years there is then a chance that that newer car will need engine attention one day.
I agree with Science Teacher - the old 996's were a great drive but of course a turbo has this alloy Nikasil cylinders!
Instead – a reliable rebuild of an M96/7 - for similar or less money – that combines a trusted warranty provides just as good (if not better) future lifespan.
“What about depreciation” I hear you say. Well all Porsches go through a similar curve and have for years, First rapid then a lift after about 4 years to 6 years, then steady depreciation ending with a long period static and finally a continual rise to very high levels. So the Gen 2 will continue to depreciate whereas most M96/7 cars have already reached that levelling out phase in Porsche depreciation and will start rising in value in the years ahead (especially with a reliable engine rebuild already completed).
Add in that financial picture and the Gen 1 comes out massively on top.
“What about the increased Gen 2 performance” I hear – well we are addressing that too for those that want it with capacity upgrades to all models 3.2 and above (for little more cost).
Sorry cannot do anything about PDK though (but not everyone likes it I hear).
With all the advice about how to extend the life of Gen 1 (LTT, thorough warming up, thicker oils, avoiding fast 2nd gear take off in a tip) now everyone’s mileage is increasing - the most common failure is just beginning to shift to include crankshaft bearing failure – that does make a rebuild after crankshaft failure much more expensive as it often not only needs a new crankshaft but usually snaps the rod and scraps the crankcases and pistons if not heads etc. So we think the merits of a preemtive rebuild are looking stronger and the economics of it are very well justified.
I don’t really want to add to the present argument about scaremongering but I guess accusations abounded at the start of the M96/7 saga (lots of IMS arguments “surely Porsche know best” etc – but led to worthwhile alternatives and I guess in 1938/9 there was plenty in that category that also turned out to be true. Surely it is only if the information greatly exaggerates the position that it can be criticised but if a scary situation exists – reporting it accurately may well scare people (you could refer to it rightly as “scary information” but at least prepares them to seek alternatives and is almost always better than not knowing the inevitable and being unable to do anything about it or make appropriate choices as a result? In my view “scaremongering” is doing something purely with the intention of promoting fear whereas all our work is absolutely and entirely intended to help owners and our customers reduce their fear and have viable alternatives – which is hardly the same thing!
Baz
If you love Gen 2 cars, dislike a reality check and want to live in a dream World where nothing will ever go wrong with your car (until it does) and/or don't like us informing you what we find out - don't read any further!
The recent posts bring a little balance into the situation - to remember previous issues with older models.
924S, 944 and 968 all had very few weak spots. No 2 big end in the 944, camshaft sprockets in the 944 S, S2 and 968 and long term - head gaskets - but overall very long lived - but each one had one short coming (it seems).
Earlier 911's gearbox synchros, 911 Sc - cylinder studs, 3.2 Carerra piston rings and 964's distorted head sealing faces.
A few more weaknesses with the M96/7 but can be fixed and a much nicer car with much better performance and moderate running costs otherwise.
Gen 2 (or 9A1) back almost if not entirely to 944/968 standards with very much better handling, comfort and performance - but unfortunately we now have had 3 scored engines to measure and inspect - all both bank 1 and 2 but all the same end of the engine and all the identical fault that creeps up and can be measured in the other cylinders but less pronounced.
Each driver has also informed us of the conditions under which they experienced the failure and all follow the very same trend.
We are currently carrying out a Nikasil alloy wet liner conversion - but there will be little else to add to a rebuild and better (and probably cheaper) than replacement crankcases that will probably exhibit the same problem.
What we don't know is - are these that failed small in number and the only few that exhibit the tendency (for some odd reason) or are they more or less all going to suffer to a greater or lesser degree in time.
My own expectation is that quite a few more will follow suit (mainly because I understand the cause and it should reveal itself on all models of that early Gen 2 era (I cannot comment of newer examples until the may fail and if so still exhibit the same trends).
Sorry I cannot brighten everyone's day but at least we are doing something about it for those that need it.
Baz
The recent posts bring a little balance into the situation - to remember previous issues with older models.
924S, 944 and 968 all had very few weak spots. No 2 big end in the 944, camshaft sprockets in the 944 S, S2 and 968 and long term - head gaskets - but overall very long lived - but each one had one short coming (it seems).
Earlier 911's gearbox synchros, 911 Sc - cylinder studs, 3.2 Carerra piston rings and 964's distorted head sealing faces.
A few more weaknesses with the M96/7 but can be fixed and a much nicer car with much better performance and moderate running costs otherwise.
Gen 2 (or 9A1) back almost if not entirely to 944/968 standards with very much better handling, comfort and performance - but unfortunately we now have had 3 scored engines to measure and inspect - all both bank 1 and 2 but all the same end of the engine and all the identical fault that creeps up and can be measured in the other cylinders but less pronounced.
Each driver has also informed us of the conditions under which they experienced the failure and all follow the very same trend.
We are currently carrying out a Nikasil alloy wet liner conversion - but there will be little else to add to a rebuild and better (and probably cheaper) than replacement crankcases that will probably exhibit the same problem.
What we don't know is - are these that failed small in number and the only few that exhibit the tendency (for some odd reason) or are they more or less all going to suffer to a greater or lesser degree in time.
My own expectation is that quite a few more will follow suit (mainly because I understand the cause and it should reveal itself on all models of that early Gen 2 era (I cannot comment of newer examples until the may fail and if so still exhibit the same trends).
Sorry I cannot brighten everyone's day but at least we are doing something about it for those that need it.
Baz
Unfortunately if I interpret the findings and combine them with my education and experience I would expect numbers to slowly ramp up. There is no way yet I can provide or substantiate the outcome.
Its a bummer getting old but one good side is I personally don't have to worry too much what will replace this work in a decade or so ahead - but my younger staff must and that is why they are fronting up some newer developments that we will be revealing later this year.
I also think that although the present demand would justify an expansion programme - we might lose the very intimacy that our work ethic is built on and then face an eventual reduction in demand when they are all fixed - so we are small enough to keep everyone busy for the foreseeable future and you cannot plan too far ahead!
Baz
Its a bummer getting old but one good side is I personally don't have to worry too much what will replace this work in a decade or so ahead - but my younger staff must and that is why they are fronting up some newer developments that we will be revealing later this year.
I also think that although the present demand would justify an expansion programme - we might lose the very intimacy that our work ethic is built on and then face an eventual reduction in demand when they are all fixed - so we are small enough to keep everyone busy for the foreseeable future and you cannot plan too far ahead!
Baz
Most other specialists are competitors and do not communicate - the exceptions have been great. It isn't so much that we have identified a problem - because it does exist - more that we have identified the cause and managed to confirm it through those that have communicated with me , sent to me pictures and details and in some cases sent me failed crankcases..
The problem isn't really "bore scoring" rather piston siezing. I needed to confirm from the small number of samples if they were consistent and to measure failed cylinder blocks - which I have now completed.
If the failures were different and the circumstances different I might have concluded that it was just random rare failures that most cars experience in very small numbers.
Thanks to those that have responded I discovered that they were all identical - both mechanically and circumstantially and as an engineer I realise that this means it is a real problem and I understand it.
As a result I am sufficiently convinced of the cause and future failure rates to provide a solution - our risk and our investment. If I am wrong I only have myself to blame. If I am right we will have provided a tested solution and made it available if and when owners need it.
So far to get to this point we have bought an engine, a gen 2 car, and some failed crankcase - so by the time we have the solution tested, manufactured and marketed it will have already cost us several thousands.
I don't see what anyone else's problem is with this. The only people who will be affected are those that experience a failure. It doesnt impact on anyone who doesn't have a failure. Whatever the various problems and points others have posted - if there are none or very few failures how does what we have done hurt anyone. If there are more is it not good for them that they will have choices over the solutions?
I also don't understand what the problem is if it is a failure that will only manifest itself after several years. This was the same with most other failures of other models,that I mentioned above.
It was just as impossibly then to even discuss those problems before everyone became generally aware of it because there were no internet or forums - as it is now and of course when the first examples emerge it is a bit I silly to claim that it cannot be a real problem because it didn t exist earlier? If the cause is time based you have to allow time for it to emerge!
Time will tell if my conclusion is right. If it is we will have provided a useful service with no cost to anyone else but if I am wrong it will be me with egg on my face and out of pocket.
We will simply have to wait to see how things develop and any opinions now can only be speculative. The only slight difference perhaps is that this is just the same as when we first announced that 944 and 968 camshaft chains needed early replacement and everyone said we must be wrong, then that there cannot be anything wrong with IMS bearings, then the same that cylinders will not be going oval or cracking and again that scoring, was very rare and not a big problem.
There are many more examples where we announced our findings firstly to receive criticism only to find as the years went by that everyone else who disagreed before was now an expert telling the whole World about the very same failures and what to do about it!
I agree that this does not prove Gen 2 seizures will necessarily become a problem but this time I have used the resource of the Internet to try and speed up information and invited help to try and be sure of the outcome and it has worked enabling an early start to find and develop the solution.
So,thanks again to all those that contributed and sorry it has not resulted in better news.
Baz
The problem isn't really "bore scoring" rather piston siezing. I needed to confirm from the small number of samples if they were consistent and to measure failed cylinder blocks - which I have now completed.
If the failures were different and the circumstances different I might have concluded that it was just random rare failures that most cars experience in very small numbers.
Thanks to those that have responded I discovered that they were all identical - both mechanically and circumstantially and as an engineer I realise that this means it is a real problem and I understand it.
As a result I am sufficiently convinced of the cause and future failure rates to provide a solution - our risk and our investment. If I am wrong I only have myself to blame. If I am right we will have provided a tested solution and made it available if and when owners need it.
So far to get to this point we have bought an engine, a gen 2 car, and some failed crankcase - so by the time we have the solution tested, manufactured and marketed it will have already cost us several thousands.
I don't see what anyone else's problem is with this. The only people who will be affected are those that experience a failure. It doesnt impact on anyone who doesn't have a failure. Whatever the various problems and points others have posted - if there are none or very few failures how does what we have done hurt anyone. If there are more is it not good for them that they will have choices over the solutions?
I also don't understand what the problem is if it is a failure that will only manifest itself after several years. This was the same with most other failures of other models,that I mentioned above.
It was just as impossibly then to even discuss those problems before everyone became generally aware of it because there were no internet or forums - as it is now and of course when the first examples emerge it is a bit I silly to claim that it cannot be a real problem because it didn t exist earlier? If the cause is time based you have to allow time for it to emerge!
Time will tell if my conclusion is right. If it is we will have provided a useful service with no cost to anyone else but if I am wrong it will be me with egg on my face and out of pocket.
We will simply have to wait to see how things develop and any opinions now can only be speculative. The only slight difference perhaps is that this is just the same as when we first announced that 944 and 968 camshaft chains needed early replacement and everyone said we must be wrong, then that there cannot be anything wrong with IMS bearings, then the same that cylinders will not be going oval or cracking and again that scoring, was very rare and not a big problem.
There are many more examples where we announced our findings firstly to receive criticism only to find as the years went by that everyone else who disagreed before was now an expert telling the whole World about the very same failures and what to do about it!
I agree that this does not prove Gen 2 seizures will necessarily become a problem but this time I have used the resource of the Internet to try and speed up information and invited help to try and be sure of the outcome and it has worked enabling an early start to find and develop the solution.
So,thanks again to all those that contributed and sorry it has not resulted in better news.
Baz
Thanks magic919 that actually confirms what we found on Saturday morning from the latest example - that there is a creeping failure mode in one area and a slight tolerance variation in another that both result in the exact same issues and reasons for the actual failures.
Can I ask if you can remember the time of year and distance travelled before you realised it had failed or perhaps if not - your typical distances you travel and if it is in traffic and areas with restricted speeds or you are able to (and enjoy) the freedom to open it up on acceleration a few minutes into your driving?
I appreciate that many owners will want to know more and I am sorry but I am not prepared yet to announce the technicality behind our findings. It has cost us a lot to get this far and our future position in the market is influenced by our confidence in our analysis of - so far - a very small number of failures just beginning to come to light.
I think announcing things too soon could do more harm than good - there is nothing after all that this delay will do to make cars fail or not and I want to be sure of my facts. Hopefully more examples will come to light and help reinforce and not contradict the direction we see things going.
You will not forget that my reasons for posting were entirely to try and gather more evidence and feedback so I could feel confident enough to continue to invest in this area to find causes and develop a solution - and not to spread gossip nor scare people unnecessarily.
I know from experience that it would have been better if we had enjoyed the facility of the Internet many years ago when other problems afflicted different models and indeed would have speeded up solutions if we had more information when the M96/7 engines started going wrong.
It would also help if the manufacturers were more open about such issues. I understand why they would not want to make it public but it would benefit owners enormously if they could confide in a technical exchange way with respected independent providers who have the facilities and scope to find and market solutions that they themselves cannot respond quickly enough to do - but then I see the difficulty they can be in and anyway a pig just flew by.
Baz
Can I ask if you can remember the time of year and distance travelled before you realised it had failed or perhaps if not - your typical distances you travel and if it is in traffic and areas with restricted speeds or you are able to (and enjoy) the freedom to open it up on acceleration a few minutes into your driving?
I appreciate that many owners will want to know more and I am sorry but I am not prepared yet to announce the technicality behind our findings. It has cost us a lot to get this far and our future position in the market is influenced by our confidence in our analysis of - so far - a very small number of failures just beginning to come to light.
I think announcing things too soon could do more harm than good - there is nothing after all that this delay will do to make cars fail or not and I want to be sure of my facts. Hopefully more examples will come to light and help reinforce and not contradict the direction we see things going.
You will not forget that my reasons for posting were entirely to try and gather more evidence and feedback so I could feel confident enough to continue to invest in this area to find causes and develop a solution - and not to spread gossip nor scare people unnecessarily.
I know from experience that it would have been better if we had enjoyed the facility of the Internet many years ago when other problems afflicted different models and indeed would have speeded up solutions if we had more information when the M96/7 engines started going wrong.
It would also help if the manufacturers were more open about such issues. I understand why they would not want to make it public but it would benefit owners enormously if they could confide in a technical exchange way with respected independent providers who have the facilities and scope to find and market solutions that they themselves cannot respond quickly enough to do - but then I see the difficulty they can be in and anyway a pig just flew by.
Baz
The old GT3 and turbo's had a separate cylinder block and separate alloy Nikasil plated cylinders fitted into the cylinder blocks.
This is probably the best solution to a variety of design and manufacturing problems that I will reveal when the full technical explanation about the Gen 2 failures is made public.
The Gen 2 (9A1) has an Alusil cylinder block cast with the crankcase in one piece and with more than 13% silicon in the casting mix.
Aluminium cab only absorb silicon up to 13% after which any excess forms silicon nodules evenly distributed throughout the casting. How big they are and how many is connected to the mixture ratio and time maintained at a high temperature. It makes the block more difficult to machine but creates a very strong casting with a surface that etched or exposed back at the cylinder wall creates a microscopically uneven surface of hard silicon spots and valleys for oil retention. - Because of the hard spots the pistons last longest with a hard coating (currently ferrous probably "ferrotec" or similar).
Original Alusil engines (924S. 944, 968) had ferrous coated pistons and lasted very well.
In between - several Alusil engines resorted to plastic coatings that were not as hard (especially at elevated temperatures) and didn't last so long. Since the process of ferrous coating was changed for health and safety reasons - the latest Gen 2 engines have a ferrous coating again (good) but I don't know if it is the same. Either a way was found to return to the original method without health and safety issues or another process was found that was similar.
M96/7 engines had Lokasil cylinder pre-forms cast in that were preformed with silicon is a porous suspension so aluminium could flow into it during the high pressure casting process forming a silicon high surface cast in near the cylinder wall and reducing the machining difficulty (and hence cost) over the remainder of the casting. They were also open deck with a cylinder tube unsupported and held roughly midway down by being cast to the cylinder block leaving a free standing tube sticking out at the top and bottom.
I have not looked into the Cayenne engines yet with great interest but think they are (or were) Alusil with plastic coated pistons but under less individual stress and closed deck construction.
I am happy to inform you all that I do not blame this failure on either the piston coating or the cylinder finish.
In the list of preferred methods of manufacturing cylinders on a quality basis I would put separate alloy Nikasil cylinders top (GT3 and turbo), fixed Nikasil plated wet alloy cylinders next, Dry alloy Nikasil liners next, Alusil closed deck cylinders next (providing some extra features were included), open deck Alusil cylinders next, if the bore was a little smaller - cast in ribbed iron liners next, if the alloy cylinder that a liner was fitted into was if the top deck supported them - iron liners next. I would not list Lokasil as I think the bonding between the silicon and the alloy is not strong enough to survive the high loadings, oil wash and temperatures - long enough. This order would almost reverse on a cost basis.
In terms of piston coatings (where necessary) I would put the original ferrous coating first, the new ferrous coating (or ferrotec) next and plastic coatings last.
With Nikasil plating the surface is so good that there is no need for a coating of any kind however a plastic coating does improve running in by making up a minute difference in expansion during the heating cycle and the inevitable slight difference in individual pistons.
It is impossible/impractical to turn an M96/7 cylinder block into one that has a separate cylinder block so that option is not available. We turn it into the closest possible to a GT3 or Turbo block by fitting an alloy Nikasil plated liner (or more accurately new wet cylinder).
The Gen 2 cylinder is part of the crankcase - very good for production. It is closed deck top and bottom (good for cylinder stability) and the engine has a type of ferrous coated piston - so you would reasonably assume it should be perfectly OK. However there are a few different ways to design these different versions and it can present a small problem in some circumstances - which the evidence has so far shown us is present.
The majority of engines will possibly never go wrong or only after acceptable mileages for a high performance sports car (depending largely on pot luck of the owners driving styles and service quality). Some will go wrong due to the above and others with every possible issue managed perfectly will still fail due to the cause we have uncovered in the engines we have had sight of and investigated.
It is obvious that the ones that failed must have some cause - the difficulty is working out if it will affect all and if so when.
Clearly as contributors to this admittedly small readership are now coming forward we discover some have failed really early as well.
This is why I asked for responses from anyone who has had a failure - to help me work out the answer to what you all want to know (and I do) to judge what the statistics for likely failure are and for me the commercial opportunities and implications.
It is a simple request and so far it has worked very well indeed and sufficiently for me to start investing in a solution.
Whether it will prove worthwhile is something only time will tell.
Any further information is welcomed - thanks
Baz
This is probably the best solution to a variety of design and manufacturing problems that I will reveal when the full technical explanation about the Gen 2 failures is made public.
The Gen 2 (9A1) has an Alusil cylinder block cast with the crankcase in one piece and with more than 13% silicon in the casting mix.
Aluminium cab only absorb silicon up to 13% after which any excess forms silicon nodules evenly distributed throughout the casting. How big they are and how many is connected to the mixture ratio and time maintained at a high temperature. It makes the block more difficult to machine but creates a very strong casting with a surface that etched or exposed back at the cylinder wall creates a microscopically uneven surface of hard silicon spots and valleys for oil retention. - Because of the hard spots the pistons last longest with a hard coating (currently ferrous probably "ferrotec" or similar).
Original Alusil engines (924S. 944, 968) had ferrous coated pistons and lasted very well.
In between - several Alusil engines resorted to plastic coatings that were not as hard (especially at elevated temperatures) and didn't last so long. Since the process of ferrous coating was changed for health and safety reasons - the latest Gen 2 engines have a ferrous coating again (good) but I don't know if it is the same. Either a way was found to return to the original method without health and safety issues or another process was found that was similar.
M96/7 engines had Lokasil cylinder pre-forms cast in that were preformed with silicon is a porous suspension so aluminium could flow into it during the high pressure casting process forming a silicon high surface cast in near the cylinder wall and reducing the machining difficulty (and hence cost) over the remainder of the casting. They were also open deck with a cylinder tube unsupported and held roughly midway down by being cast to the cylinder block leaving a free standing tube sticking out at the top and bottom.
I have not looked into the Cayenne engines yet with great interest but think they are (or were) Alusil with plastic coated pistons but under less individual stress and closed deck construction.
I am happy to inform you all that I do not blame this failure on either the piston coating or the cylinder finish.
In the list of preferred methods of manufacturing cylinders on a quality basis I would put separate alloy Nikasil cylinders top (GT3 and turbo), fixed Nikasil plated wet alloy cylinders next, Dry alloy Nikasil liners next, Alusil closed deck cylinders next (providing some extra features were included), open deck Alusil cylinders next, if the bore was a little smaller - cast in ribbed iron liners next, if the alloy cylinder that a liner was fitted into was if the top deck supported them - iron liners next. I would not list Lokasil as I think the bonding between the silicon and the alloy is not strong enough to survive the high loadings, oil wash and temperatures - long enough. This order would almost reverse on a cost basis.
In terms of piston coatings (where necessary) I would put the original ferrous coating first, the new ferrous coating (or ferrotec) next and plastic coatings last.
With Nikasil plating the surface is so good that there is no need for a coating of any kind however a plastic coating does improve running in by making up a minute difference in expansion during the heating cycle and the inevitable slight difference in individual pistons.
It is impossible/impractical to turn an M96/7 cylinder block into one that has a separate cylinder block so that option is not available. We turn it into the closest possible to a GT3 or Turbo block by fitting an alloy Nikasil plated liner (or more accurately new wet cylinder).
The Gen 2 cylinder is part of the crankcase - very good for production. It is closed deck top and bottom (good for cylinder stability) and the engine has a type of ferrous coated piston - so you would reasonably assume it should be perfectly OK. However there are a few different ways to design these different versions and it can present a small problem in some circumstances - which the evidence has so far shown us is present.
The majority of engines will possibly never go wrong or only after acceptable mileages for a high performance sports car (depending largely on pot luck of the owners driving styles and service quality). Some will go wrong due to the above and others with every possible issue managed perfectly will still fail due to the cause we have uncovered in the engines we have had sight of and investigated.
It is obvious that the ones that failed must have some cause - the difficulty is working out if it will affect all and if so when.
Clearly as contributors to this admittedly small readership are now coming forward we discover some have failed really early as well.
This is why I asked for responses from anyone who has had a failure - to help me work out the answer to what you all want to know (and I do) to judge what the statistics for likely failure are and for me the commercial opportunities and implications.
It is a simple request and so far it has worked very well indeed and sufficiently for me to start investing in a solution.
Whether it will prove worthwhile is something only time will tell.
Any further information is welcomed - thanks
Baz
Chris - firstly I pass on my hope that your engine is OK. Secondly can I also add (for those that cannot wait to find a way to discredit what we do) that we are perfectly busy enough (flat out in fact) and do not need any more additional engines to rebuild. I rather hope that if this proves to be a problem it emerges in numbers in many months time when M96/7 rebuild numbers start to reduce (if indeed they ever do).
You would need to pay for a boroscope check. If it has seized they usually then squash that piston smaller and carry on running but usually with noises and higher oil consumption.
If it slightly seized (or nipped) it may only show higher oil consumption.
It will probably be cylinder 1 or 4, but it is possible for any cylinder at this stage (they are the only ones we have identified and measured that show the full fault although cylinders 2 and 5 show some signs of the same issue). So far cylinders 3 and 6 look unlikely but that may just be because of the relatively small sample so far.
If it has failed then apart from the higher oil consumption it will eventually start knocking.
I somehow doubt you have a seizure problem - but if it is bothering you it would be a good thing to have it checked. Alusil bores show up better than Nikasil ones as the Nikasil finish reflects light better and can fool anyone inexperienced at looking.
Good luck,
Baz
You would need to pay for a boroscope check. If it has seized they usually then squash that piston smaller and carry on running but usually with noises and higher oil consumption.
If it slightly seized (or nipped) it may only show higher oil consumption.
It will probably be cylinder 1 or 4, but it is possible for any cylinder at this stage (they are the only ones we have identified and measured that show the full fault although cylinders 2 and 5 show some signs of the same issue). So far cylinders 3 and 6 look unlikely but that may just be because of the relatively small sample so far.
If it has failed then apart from the higher oil consumption it will eventually start knocking.
I somehow doubt you have a seizure problem - but if it is bothering you it would be a good thing to have it checked. Alusil bores show up better than Nikasil ones as the Nikasil finish reflects light better and can fool anyone inexperienced at looking.
Good luck,
Baz
GT4P - in answer to your first post - watch this space!
Chris W You confused me too - glad it is OK.
Ooid This is not a surface finish problem. I appreciate that it must be very frustrating for me not to come straight out with my conclusions - but this post was initiated by me to obtain more information about failures so I could investigate thoroughly and only report more solid facts and not speculation. I feel I have a duty to be really sure with such an emotive subject. I have purposely not revealed all yet and only tried to build my information data base on scant responses. I understand that just like the M96/7 engines - there have been some replaced during the first ownership by Porsche and therefore the independent specialists only get to find out if there is a problem some way down the line - and then just trying to find out more invokes all sorts of negative and reactionary responses confusing things - more soon.
GT4P - so far it is only 3.8's reported and I have not yet inspected or stripped 3.6 (but I have bought one and it is in the pipeline as there is something I want to measure).
If Porsche have followed their usual generic policy (and I have already worked out that the cylinder blocks 3.6 and 3.8 are the same height despite different stoke engines corrected via the piton pin offset - as they did with the M96/7 range) then if the cylinder block casting core is the same for both it would mean that the cylinder walls in the 3.6 would be 2mm thicker. If that turns out to be the case it may either delay the problem further or eliminate it all together. Our 3.6 is a high mileage example because we also want to see how other components are lasting (like crankshaft shells and rings) and this is all part of a very serious and professional approach that is typical of how we go about resolving such issues. It unfortunately takes time but those who may have read about our opinions over a decade ago (regarding M96/7 issues) and 944/968 etc years before will know that when we do firm up on a cause it is usually spot on and as a result our solutions have always been top of the market.
Overall - if an engine exhibits this trend - I don't think it can be resolved with replacing the crankcases.
Replacement crankcases may have the same proportion of random ones that tend to fail unless Porsche understood the problem soon enough to change something else to solve it (which I doubt purely on a time scale between design, tooling and manufacturing - if it takes a long time to reveal itself after the start of the new production run). Nothing seemed to have been done about IMS bearings for a long time (and that was an easy potential retrofit) and nothing was done about cylinder cracking in the M96 and scoring in the M97 range at all.
The most important advice I can give at the moment is to be patient from a cold start to delay high power until the engine and oil has fully warmed up (especially when it is cold). If you only undertake short journeys I am sorry to advise avoiding high full throttle power delivery all together - less throttle but still revving it would be OK.
Hopefully you will all appreciate that we are on our own in looking into this - a small business - with many other priorities and this is just the start of trying to find out what sort of problem caused these failures and if it is likely to grow into a more serious issue.
Baz
Chris W You confused me too - glad it is OK.
Ooid This is not a surface finish problem. I appreciate that it must be very frustrating for me not to come straight out with my conclusions - but this post was initiated by me to obtain more information about failures so I could investigate thoroughly and only report more solid facts and not speculation. I feel I have a duty to be really sure with such an emotive subject. I have purposely not revealed all yet and only tried to build my information data base on scant responses. I understand that just like the M96/7 engines - there have been some replaced during the first ownership by Porsche and therefore the independent specialists only get to find out if there is a problem some way down the line - and then just trying to find out more invokes all sorts of negative and reactionary responses confusing things - more soon.
GT4P - so far it is only 3.8's reported and I have not yet inspected or stripped 3.6 (but I have bought one and it is in the pipeline as there is something I want to measure).
If Porsche have followed their usual generic policy (and I have already worked out that the cylinder blocks 3.6 and 3.8 are the same height despite different stoke engines corrected via the piton pin offset - as they did with the M96/7 range) then if the cylinder block casting core is the same for both it would mean that the cylinder walls in the 3.6 would be 2mm thicker. If that turns out to be the case it may either delay the problem further or eliminate it all together. Our 3.6 is a high mileage example because we also want to see how other components are lasting (like crankshaft shells and rings) and this is all part of a very serious and professional approach that is typical of how we go about resolving such issues. It unfortunately takes time but those who may have read about our opinions over a decade ago (regarding M96/7 issues) and 944/968 etc years before will know that when we do firm up on a cause it is usually spot on and as a result our solutions have always been top of the market.
Overall - if an engine exhibits this trend - I don't think it can be resolved with replacing the crankcases.
Replacement crankcases may have the same proportion of random ones that tend to fail unless Porsche understood the problem soon enough to change something else to solve it (which I doubt purely on a time scale between design, tooling and manufacturing - if it takes a long time to reveal itself after the start of the new production run). Nothing seemed to have been done about IMS bearings for a long time (and that was an easy potential retrofit) and nothing was done about cylinder cracking in the M96 and scoring in the M97 range at all.
The most important advice I can give at the moment is to be patient from a cold start to delay high power until the engine and oil has fully warmed up (especially when it is cold). If you only undertake short journeys I am sorry to advise avoiding high full throttle power delivery all together - less throttle but still revving it would be OK.
Hopefully you will all appreciate that we are on our own in looking into this - a small business - with many other priorities and this is just the start of trying to find out what sort of problem caused these failures and if it is likely to grow into a more serious issue.
Baz
A completely new engine with superior features. The number of weak points are minimal and they have proven very reliable.
The identical fault we have analysed was present in all 5 of the examples we have had access to (and others we have heard about or seen pictures of). Some faults require large numbers to analyse and circumstantial feedback to be sure of a cause - but others can be resolved from just one sample (if the mistake is obvious).
We are still testing out our theory about the cause but I am sure there will be no need to see any more to confirm the technical issue and conditions - causing the seizures.
We are presently concentrating on the repair of the ones we have and the design of tooling and some other products that might emerge in the future.
More on this soon - but little to worry about as failures seem low in numbers and then after relatively high mileages.
Still more feedback would be greatly appreciated from anyone who had an engine replaced - mileage covered and ambient conditions at the time would also help.
Thanks,
Baz
The identical fault we have analysed was present in all 5 of the examples we have had access to (and others we have heard about or seen pictures of). Some faults require large numbers to analyse and circumstantial feedback to be sure of a cause - but others can be resolved from just one sample (if the mistake is obvious).
We are still testing out our theory about the cause but I am sure there will be no need to see any more to confirm the technical issue and conditions - causing the seizures.
We are presently concentrating on the repair of the ones we have and the design of tooling and some other products that might emerge in the future.
More on this soon - but little to worry about as failures seem low in numbers and then after relatively high mileages.
Still more feedback would be greatly appreciated from anyone who had an engine replaced - mileage covered and ambient conditions at the time would also help.
Thanks,
Baz
Gassing Station | Porsche General | Top of Page | What's New | My Stuff