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
If you post here Baz you have to expect the thread to go where members want. So here goes.
Much as I love PH, and respect Baz, this is the downside of the internet. A few failures and rumours start a forest fire and now 997.2 owners are going to be s
tting themselves too. And I write as a 997.1 owner who has given up worrying and just enjoying the thing - 8 years in and 50k and so far so good.
PS but when, or if, it develops problems it will be off to Baz and his research has to start somewhere. Sell your 997.2 quick
Much as I love PH, and respect Baz, this is the downside of the internet. A few failures and rumours start a forest fire and now 997.2 owners are going to be s
tting themselves too. And I write as a 997.1 owner who has given up worrying and just enjoying the thing - 8 years in and 50k and so far so good.PS but when, or if, it develops problems it will be off to Baz and his research has to start somewhere. Sell your 997.2 quick
Edited by drmark on Sunday 5th February 13:12
drmark said:
Much as I love PH, and respect Baz, this is the downside of the internet. A few failures and rumours start a forest fire and now 997.2 owners are going to be stting themselves too. And I write as a 997.1 owner who has given up worrying and just enjoying the thing - 8 years in and 50k and so far so good.
PS but when, or if, it develops problems it will be off to Baz and his research has to start somewhere. Sell your 997.2 quick
Covered 80,000 fault free miles in gen 1 architecture engines. Had to replace one misty RMS. Thats it. By comparison as a dd my Mezger turbo was a lemon with a total failure. Go figure!tting themselves too. And I write as a 997.1 owner who has given up worrying and just enjoying the thing - 8 years in and 50k and so far so good.PS but when, or if, it develops problems it will be off to Baz and his research has to start somewhere. Sell your 997.2 quick
Not sure about this post. Respect Baz but there must be better ways of getting data.
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
hartech said:
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
I think the fact that you may be struggling to get data speaks volumes about how much better the gen 2 dpi engine is. Can't think of anywhere else many people would go with a broken Porsche engine than Hartech. Even my own Indy 9e sends broken non mezger engines to you for rebuild. I imagine other indies do the same?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
Hi, it seems the Porsche DFi engines introduced in the 987/997 cars are a simply massive leap forward in terms of reliability over their problematic predecessor, and in one fell swoop they appear to have addressed the design flaws that blighted the earlier units. In fact so reliable have they been we've only heard of a handful of isolated issues with them, which if you take into account the quantities that have been manufactured by Porsche over the past 7-8 years, is a testament to just how well engineered these engines are.
As well renowed M96/97 engine remanufacturers we like to think we're ahead of the curve, so if you've had ANY engine issues with a car with a Gen 2 DFi engine, do please drop us an email and I'll send you a very brief questionaire regarding the nature of the fault, mileage etc.
Many thanks
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
Slickhillsy said:
+1. Keep tapping this info Baz. You never know the negatives on here may need to come knocking one day, eager to use the fruits of your labour.
I don't think anyone is doubting that (nor indeed our general appreciation of what Baz has done or is doing) but there's ways and means of gaining information/feedback without scaremongering. And as we know, whilst there were a good many 996/997/986/987 engine failures, that number expressed as percentage of the total quantities of cars produced between '98 and '09 isn't anything like as bad as internet folklore would have us believe. The internet is a wonderful thing, but it only takes a few empty barrels to make a lot of noise.If there is nothing intrinsically wrong with the DFi engines, and from what Baz is saying the vast majority of issues that afflicted the early non_DFi engines would appear to have been addressed. A thread detailing any issues is probably going to create a lot of noise for what appears to be at the moment, insignificant numbers. As Baz has said, only time will tell whether higher mileage, older DFi engined cars develop issues, but at this moment in time there's nothing to indicate that any problems are widespread. That the DFi engines have now been around 8 years without the mass hysteria surrounding reliability issues that affected the non_DFi engines, would tend to support that viewpoint.
The only failures I have ever read about of the dfi over the years across the Internet are of very early 2.9 caysters having problems with piston/ring coatings causing scoring and engine failure but Porsche upgraded these pretty early on and I believe magic919 had a random failure with a 997.2
hartech said:
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.
That failure mechanism is called "low cycle fatigue". It's something that engine designers do look at for new engines using 3D FEA simulation techniques that predict the number of cycles to failure. When designing a new engine, you'll design to an acceptable number of cycles before failure. The number of cycles will depend on process and will vary depending on duty cycle etc.I'd assume that low cycle fatigue prediction is something that Porsche would look at as part of their engine design process, but you could potentially have someone else do their own simulation for you which would highlight the weak spots? Not sure whether the level of input data required for the simulation would only be accessible from Porsche themselves though.
anonymous said:
[redacted]
No need to apologise my dear boy, and as an aside, I think my use of said word IS justified. Whether you agree with it, or indeed like it, matters not, for 'tis my opinion, and just as you're entitled to yours, I'm entitled to mine 
I'm afraid I've not the inclination to make numerous posts debating said difference in opinion on an internet forum these days
Life's simply too short for such nonsense GT4P said:
The only failures I have ever read about of the dfi over the years across the Internet are of very early 2.9 caysters having problems with piston/ring coatings causing scoring and engine failure but Porsche upgraded these pretty early on and I believe magic919 had a random failure with a 997.2
You forgot about the entire initial early run of 991 gt3 engines (9A1 DFI variant after all) and continued failure of the replacement gt3 engines which may or may not have been fixed at long last now 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
anonymous said:
[redacted]
And whilst I know this concept is completely, totally and utterly unthinkable to your good self, so do you ! ! 
As for your other comments Jeremy, I suggest you read and (and note) the closing comment in my previous post. Much as you'd rather it otherwise, it's simply not up for further debate on my part
Of course, if you'd like to meet and 
over a brew, you know where to find me. Gassing Station | Porsche General | Top of Page | What's New | My Stuff