Feedback from Gen 2 engine failures
Discussion
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
I do think that all the hate towards a 997.1 and the absolute praise of the 997.2 will change around in time.
Give it 10 to 15 years and the gen 1 car will be seen as the older style (let's face it is it basically the same as a 996) car and by that time all the engines will be sorted, very much like the 964's now. The 997.2 will I think be seen as the more modern led lights, direct injection and normal usual car.......I am of course completely bias...
Give it 10 to 15 years and the gen 1 car will be seen as the older style (let's face it is it basically the same as a 996) car and by that time all the engines will be sorted, very much like the 964's now. The 997.2 will I think be seen as the more modern led lights, direct injection and normal usual car.......I am of course completely bias...
YoungMD said:
I do think that all the hate towards a 997.1 and the absolute praise of the 997.2 will change around in time.
Give it 10 to 15 years and the gen 1 car will be seen as the older style (let's face it is it basically the same as a 996) car and by that time all the engines will be sorted, very much like the 964's now. The 997.2 will I think be seen as the more modern led lights, direct injection and normal usual car.......I am of course completely bias...
Give it 10 to 15 years and the gen 1 car will be seen as the older style (let's face it is it basically the same as a 996) car and by that time all the engines will be sorted, very much like the 964's now. The 997.2 will I think be seen as the more modern led lights, direct injection and normal usual car.......I am of course completely bias...
Some of us have already owned 9x6 and 9x7.1 cars and some with the experience of failure at very low miles!
Ain't going to happen !
Edited by GT4P on Thursday 9th February 22:47
I've looked at probably 9 cars last year (997.1) and 7 out of 9 had an engine replacement already. (The rest was unknown). We had one in the family as a company car before 2008 which also had an engine replacement and sent back to the dealer as it was a lease. Never heard any 997.2 issue both from friends and few cars I've looked at. They are obviously much superior design but I really gave up on both gen2 and gen1 997 for now, it's too much hassle at the end. 987.2 or 981 is a better choice or going with early 986s as parts are cheap as chips comparing to the rest and the worst case scenario engine rebuilds are more reliable and affordable. In the end, you do have a proper flat6 fun with less hassle or worries 
There is a reason why air-cooled earlier models (particularly 993s) got so expensive lately, in addition to the other factors, people just want to enjoy driving these without too much worry. I could afford and get one but knowing that I would have purchased one probably much cheaper a few years ago, stops me buying it like probably many others. You would probably get a decent Audi R8 v10 nowadays with decent fairly low-mile 993 prices, much more fun and performance for a car and proper Audi reliability. I might be wrong but personally 997.1's would probably get much cheaper and reliable in the future, as more and more specialists like hartech rebuilding and future-protecting these engines for longer term use.
There is a reason why air-cooled earlier models (particularly 993s) got so expensive lately, in addition to the other factors, people just want to enjoy driving these without too much worry. I could afford and get one but knowing that I would have purchased one probably much cheaper a few years ago, stops me buying it like probably many others. You would probably get a decent Audi R8 v10 nowadays with decent fairly low-mile 993 prices, much more fun and performance for a car and proper Audi reliability. I might be wrong but personally 997.1's would probably get much cheaper and reliable in the future, as more and more specialists like hartech rebuilding and future-protecting these engines for longer term use.
GT4P said:
The 964 and 993 were around before the internet yet I have heard of engine failures back in the 90s and rebuilds before a 100k mainly top ends so most likely just as reliable as a gen2! The only thing the gen2 is lacking is nikasil bores
Yes it would have been interesting to have had the internet in eighties when the 3.2 went through a phase of being built with weak valve guides (mine needed a top end rebuild at 45K and I know of at least one other on here that did too). Then in the nineties I had a leaky 964 that needed redoing (plus duff DM flywheel). My 993 was good but my only Porsches that have been as trouble free as you would expect were both front engined a 928 GTS and a 968 - I did nearly a 100k in those and just serviced them and replaced brakes.Edited by Discombobulate on Friday 10th February 16:39
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
Discombobulate said:
my only Porsches that have been as trouble free as you would expect were both front engined a 928 GTS and a 968 - I did nearly a 100k in those and just serviced them and replaced brakes.
Always wondered about this,it seems like many front engined porsche owners (specifically 928) maintain their cars over 150-200k without any problem. Now that having all experts here, would it be possible to claim that maybe flat 6 engine design is not exactly the best location having either rear or mid engine layout? due to driving dynamics + Flat 6 behaviour -horizontal movement-, affects and create more stress or wear on the engine components comparing to front engine cars? Especially considering some low quality material (metal) were used on both m96/m97 in addition to lubrication and cooling inefficiencies?Edited by Discombobulate on Friday 10th February 16:39
Main issue that seems hard if not unavoidable ooid is that flat engines tend to pool oil on the underside of the cylinder when the engine has stopped.
The 4 pots were massively over-engineered for their power output compared to the modern engines so that is another difference, having said that as Baz knows all to well having seem em over the years some did bore score but this was pre-internet and since then its only a small number of enthusiasts with the cars that ever go on forums much.
The 4 pots were massively over-engineered for their power output compared to the modern engines so that is another difference, having said that as Baz knows all to well having seem em over the years some did bore score but this was pre-internet and since then its only a small number of enthusiasts with the cars that ever go on forums much.
Discombobulate said:
My 993 was good but my only Porsches that have been as trouble free as you would expect were both front engined a 928 GTS and a 968 - I did nearly a 100k in those and just serviced them and replaced brakes.
This is correct. 928's in particular are good for at least 300K before any kind of non-service engine block/piston work is worth considering, engines can easily take 650 bhp, so with a bog standard 350 hp we can see how under stressed they are. Edited by Discombobulate on Friday 10th February 16:39
Some more info here:
The engine blocks used in the Porsche 928 are well made pieces with very good cooling capacity. These blocks are cast from an aluminum alloy referred to as Reynolds 390. This was referred to as Alusil on the Porsche (and other) engine blocks. While difficult to cast, Porsche's supplier got these right. The basis for the all aluminum engine block is to maximise heat transfer and to run extra tight piston to wall clearances. All 928 engine blocks are stamped with a tolerance group number after the finish honing process is completed. Each piston was selected based on the bore tolerance group.
hartech said:
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
Baz, you already brightened my day --- with this.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
"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. "
Three from the last eight years of production ??
What will you do when you have repaired them all ;-)
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
I'm also rather puzzled Baz, you say that you have identified a problem, albiet in only three engines so far, that you expect to manifest itself in time in all gen 2's. You suggest it's some kind of bore scoring but give no details of mileage, usage, commonality, lubrication etc. You expect to be retired when this happens? I would have thought that your contacts and networks in the business would be far more effective in gathering stats than appealing to the relatively few who read these forums. If I were a suspicious person I might conclude that the idea is being circulated that a rebuilt gen1 is better than a gen2 ?
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
hartech said:
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.
7and911 said:
Baz,
My 991.1 engine is currently being investigated by OPC for a possible similar issue (2014, C4S, still under warranty & only 5000 miles). I am aware of a couple of 991 engines also replaced by Porsche.
Christ!! I've owned three 991's since 2012 (including my 991.2 Targa 4S) no problems for me (touch wood)My 991.1 engine is currently being investigated by OPC for a possible similar issue (2014, C4S, still under warranty & only 5000 miles). I am aware of a couple of 991 engines also replaced by Porsche.
As an owner of a Gen 2, I've been following this with interest.
The cars are getting a little older now and I'm sure we'll start to see some "bespoke concerns" appearing - some of these engines will be getting on for big mileages now. As Baz and others say, it's a context thing - each model has their own weak points - I hate to think the reputation the 964 would have had if these fora were around back in the day.
From an ownership point of view, I guess all one can reasonably do is ensure the maintenance is conducted on time and to a good standard, and to leave the rest to the mechanical Gods (and be thankful there's no IMS to worry about); from Baz's point of view, I think there's a lot of us keen to hear from the findings of his work.
The cars are getting a little older now and I'm sure we'll start to see some "bespoke concerns" appearing - some of these engines will be getting on for big mileages now. As Baz and others say, it's a context thing - each model has their own weak points - I hate to think the reputation the 964 would have had if these fora were around back in the day.
From an ownership point of view, I guess all one can reasonably do is ensure the maintenance is conducted on time and to a good standard, and to leave the rest to the mechanical Gods (and be thankful there's no IMS to worry about); from Baz's point of view, I think there's a lot of us keen to hear from the findings of his work.
Mine went 4 years ago at under 15k miles, so I wouldn't suggest it's age related. I've done nearly 40k miles on the new engine, plus 30k in another one and no signs of trouble.
I'd complained of a slight engine knock and high oil consumption just before mine went bang. If I was doing it again I'd still buy a Gen 2, but a later one.
I'd complained of a slight engine knock and high oil consumption just before mine went bang. If I was doing it again I'd still buy a Gen 2, but a later one.
Hartech did point out some time ago that he had concerns with the alusil lining and the coating on the Pistons/rings!
What would be good is for some one to develop is 4.0 litre blocks with decent Pistons/rings and nikasil linings or existing block when seized to be bored out with nikasil linings win win for owners seeking more power!
It sounds like heat related seizures to me although I am no engineer now if this problem is heat related as the engines do run extremely hot for emissions and so does the third radiator on some cars help ,and does the sport button on say the gt4 which opens the third radiator so the engine runs at a cooler temperature which I always press a few miles from home to cool the engine!
Thie above is purely speculation on my part!
Interestingly the 991gt3 is basically the same engine but does it still have the nikasil linings of the older gt3?
What would be good is for some one to develop is 4.0 litre blocks with decent Pistons/rings and nikasil linings or existing block when seized to be bored out with nikasil linings win win for owners seeking more power!
It sounds like heat related seizures to me although I am no engineer now if this problem is heat related as the engines do run extremely hot for emissions and so does the third radiator on some cars help ,and does the sport button on say the gt4 which opens the third radiator so the engine runs at a cooler temperature which I always press a few miles from home to cool the engine!
Thie above is purely speculation on my part!
Interestingly the 991gt3 is basically the same engine but does it still have the nikasil linings of the older gt3?
Edited by GT4P on Sunday 12th February 12:43
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