Has your 996 or 997 engine had a major rebuild?
Poll: Has your 996 or 997 engine had a major rebuild?
Total Members Polled: 867
Discussion
From memory, most of the magazines were simply replicating blind assumptions and ill informed rhetoric from the forums as fact for several years. It had somehow became the accepted wisdom that the 996.1 was the real problem and the 996.2 much lesser an issue. The forums misled the magazines, who then misled the forums, who then misled the next batch of journos, and so on and it's taken a long time for some facts to emerge out of the haze. Now the perception is completely reversed, a total 180degree flip. Its amusing at times to take out an old Porsche magazine (as in maybe even up to just two years ago) and see the historical perspective (and generally complete inaccuracy). But then, that's Porsche magazines for you.
I agree it is very frustrating to regularly read misinformed details stated as facts when we have researched the subject for many years and equally difficult to deal with customers who believe the wrong information regularly dished out in the media and indeed by some businesses eager to exploit their own particular product or solution. It must make it very difficult for the public to know who to believe and - much more sinister - is that this makes it easer for unscrupulous businesses to exploit - and this is often behind why we receive engines for a second rebuild after following the wrong advice initially.
While I was providing information and photos recently for a future magazine article about the whole subject I directed the journalist to our buyers guide (sections 4 and 5) and despite apologising for the fact it was written many years ago (and under a re-write now with a more modern format to bring things more up to date) I was surprised how long ago (often a decade ago) despite being at the beginning of data acquisition and feedback we accurately identified the main causes of the problems and came up with solutions that have worked ever since. That was reinforced when many of the photos we provided had dates over 8 years ago in the computer file.
My point is not to blow our own trumpet but more serious and relevant to the recent comments - to me it reinforces the degree by which information can be corrupted to the point that hardly any one knows what to believe when actually the true facts have been available and clear for many years and have not changed.
I remember us being wary to state too strongly any criticism of the original designs (for obvious reasons) that now we would feel more confident to state and I hope our new version will come across more positively to help readers but it is a huge subject and the difficulty I have had re-writing it is that it is rather like catastrophe theory where a number of minor issues (that in themselves might not lead to a disaster) combine in some circumstances to create an engineering leap into the disaster zone. Because there are and a lot of small contributory factors often crossing into different areas of expertise and technology (many still disputed) it is difficult not to get bogged down in lengthy explanations and easy for others to pick out and argue about individual points to muddy what is actually now a very clear picture of issues and failures points.
The gradual (and cynical) change in the regulations for motor sport engines over the last thirty years has achieved what the large manufacturers wanted and squeezed out the small businesses that used to compete even at GP level (which I did for example with a miniscule budget 35 years ago (and so did other business and even individuals like Helmut Fath who designed built his own engine to win the sidecar World Championship - imagine that today)) and as a result they have gradually pulled back into their house the knowledge that thousands more used to understand. One motor cycle World Championship I believe now just using one factory source of engines - for example while even in our own Porsche cup events we find restrictions on who can rebuild engines and what you can do to them (almost nothing). When small businesses and individuals designed and made their own engines that the public could see for themselves were every bit as good as the manufacturers (despite their bigger budgets) it gave credence to those individuals opinions and confidence to the public about who to listen to. It also gave those engineers the opportunity to develop their skills and learn stuff that there is little opportunity these days - and consequently there is very little now they can rely on to judge who to believe! and those they can seem to be getting older. This is one of the reasons we go racing and involve our young engineers and graduates - to provide opportunities for learning and developing that fewer and fewer businesses are doing - enabling manufacturers tog et away with increasingly poor products.
All this means there are fewer people who have enough expertise and experience to know what is what, who to trust and how to write about it reliably - with commercial interests increasingly driving everything forward as each decade unfolds.
This is the reason why I often mention the number of engines we rebuild - not to crow about it but simply as a means to at least enable the public to realise you must be doing something right and therefore can be trusted (and I would include in that scenario - for balance - anyone else that has been doing it for years successfully). If a supplier is just pushing one product connected with engine problems but with little overall rebuild history - you have to question their motives when they clearly have not tested alternatives and just focus on selling the one solution that have manufactured for them - whereas a business that has come up with engineering solutions on various fronts and with lots of different issues they can manufacture themselves is more likely to be offering the market a product more broadly based on experience and judgement.
If magazines and journalists also concentrated more on the people that have done the most repairs for the most years and have their own internal engineering facilities and experts - rather than trying too hard to come up with more sensational articles with glamorous pictures but little content - and spent more time researching their subject and verifying data - they would do the public a better service (i.e. were more concerned about quality than circulation).
The general public combined with the expansion of the Internet have not helped with many using it as an opportunity to appear knowledgeable (when they are not), pursuing a vendetta, trying to gain commercial favour or simply enjoying stirring trouble - confusing readers seeking genuine advice about a serious problem they didn't expect and probably find it difficult to afford to fix.
I have no easy answer but the problem is probably worse than alluded to above and I have great sympathy with just those seeking reliable advice with so much contradictory stuff out there.
Baz
While I was providing information and photos recently for a future magazine article about the whole subject I directed the journalist to our buyers guide (sections 4 and 5) and despite apologising for the fact it was written many years ago (and under a re-write now with a more modern format to bring things more up to date) I was surprised how long ago (often a decade ago) despite being at the beginning of data acquisition and feedback we accurately identified the main causes of the problems and came up with solutions that have worked ever since. That was reinforced when many of the photos we provided had dates over 8 years ago in the computer file.
My point is not to blow our own trumpet but more serious and relevant to the recent comments - to me it reinforces the degree by which information can be corrupted to the point that hardly any one knows what to believe when actually the true facts have been available and clear for many years and have not changed.
I remember us being wary to state too strongly any criticism of the original designs (for obvious reasons) that now we would feel more confident to state and I hope our new version will come across more positively to help readers but it is a huge subject and the difficulty I have had re-writing it is that it is rather like catastrophe theory where a number of minor issues (that in themselves might not lead to a disaster) combine in some circumstances to create an engineering leap into the disaster zone. Because there are and a lot of small contributory factors often crossing into different areas of expertise and technology (many still disputed) it is difficult not to get bogged down in lengthy explanations and easy for others to pick out and argue about individual points to muddy what is actually now a very clear picture of issues and failures points.
The gradual (and cynical) change in the regulations for motor sport engines over the last thirty years has achieved what the large manufacturers wanted and squeezed out the small businesses that used to compete even at GP level (which I did for example with a miniscule budget 35 years ago (and so did other business and even individuals like Helmut Fath who designed built his own engine to win the sidecar World Championship - imagine that today)) and as a result they have gradually pulled back into their house the knowledge that thousands more used to understand. One motor cycle World Championship I believe now just using one factory source of engines - for example while even in our own Porsche cup events we find restrictions on who can rebuild engines and what you can do to them (almost nothing). When small businesses and individuals designed and made their own engines that the public could see for themselves were every bit as good as the manufacturers (despite their bigger budgets) it gave credence to those individuals opinions and confidence to the public about who to listen to. It also gave those engineers the opportunity to develop their skills and learn stuff that there is little opportunity these days - and consequently there is very little now they can rely on to judge who to believe! and those they can seem to be getting older. This is one of the reasons we go racing and involve our young engineers and graduates - to provide opportunities for learning and developing that fewer and fewer businesses are doing - enabling manufacturers tog et away with increasingly poor products.
All this means there are fewer people who have enough expertise and experience to know what is what, who to trust and how to write about it reliably - with commercial interests increasingly driving everything forward as each decade unfolds.
This is the reason why I often mention the number of engines we rebuild - not to crow about it but simply as a means to at least enable the public to realise you must be doing something right and therefore can be trusted (and I would include in that scenario - for balance - anyone else that has been doing it for years successfully). If a supplier is just pushing one product connected with engine problems but with little overall rebuild history - you have to question their motives when they clearly have not tested alternatives and just focus on selling the one solution that have manufactured for them - whereas a business that has come up with engineering solutions on various fronts and with lots of different issues they can manufacture themselves is more likely to be offering the market a product more broadly based on experience and judgement.
If magazines and journalists also concentrated more on the people that have done the most repairs for the most years and have their own internal engineering facilities and experts - rather than trying too hard to come up with more sensational articles with glamorous pictures but little content - and spent more time researching their subject and verifying data - they would do the public a better service (i.e. were more concerned about quality than circulation).
The general public combined with the expansion of the Internet have not helped with many using it as an opportunity to appear knowledgeable (when they are not), pursuing a vendetta, trying to gain commercial favour or simply enjoying stirring trouble - confusing readers seeking genuine advice about a serious problem they didn't expect and probably find it difficult to afford to fix.
I have no easy answer but the problem is probably worse than alluded to above and I have great sympathy with just those seeking reliable advice with so much contradictory stuff out there.
Baz
Edited by hartech on Sunday 8th February 11:16
I have had my 997 Carrera S since January 2006. I bought it with 4000kms on the clock, 2005 model.
Since I bought the car I had 2 seized engines. The first one at 70k kms December 2010. Porsche supplied an exchange motor, at my cost, since the warranty and service plan had expired. When this happened I spoke to a mechanic in Germany who mad sit very clear to me that there is a problem as Porsche offered the exchange motor option. At that time the price was Euro 10k. 6 weeks ago the second engine seized, I had done 68k kms. Unfortunately, Porsche has not taken any responsibility, and have only referred me to the data off the ECU which is very vague. Anyway, I am not looking to import a second hand 997 3,8ltr motor as Porsche SA is wanting a minimum of Euro 30k to fix the motor. There are no more exchange motor deal available. They must have run out..... It is most disappointing as I loved my car, but nobody is taking responsibility when it is very clear that there is a problem with that motor.
Since I bought the car I had 2 seized engines. The first one at 70k kms December 2010. Porsche supplied an exchange motor, at my cost, since the warranty and service plan had expired. When this happened I spoke to a mechanic in Germany who mad sit very clear to me that there is a problem as Porsche offered the exchange motor option. At that time the price was Euro 10k. 6 weeks ago the second engine seized, I had done 68k kms. Unfortunately, Porsche has not taken any responsibility, and have only referred me to the data off the ECU which is very vague. Anyway, I am not looking to import a second hand 997 3,8ltr motor as Porsche SA is wanting a minimum of Euro 30k to fix the motor. There are no more exchange motor deal available. They must have run out..... It is most disappointing as I loved my car, but nobody is taking responsibility when it is very clear that there is a problem with that motor.
Sorry to hear about this psl it is a sad state of affairs and even though Porsche provide a replacement - without changing the technical things that cause the failures it is likely to reoccur (as you have discovered).
Just in case it helps - we have successfully supplied rebuilt engines, bottom ends and crankcases to customers all over the World and because they incorporate different internals and various subtle but important modifications - they have proven extremely reliable. The cost is also significantly less than the replacements you have mentioned (even with shipping) - however the down side is that you would need a reliable source to remove and re-fit the engine and/or strip and rebuild it.
No one else Worldwide has had a problem doing this - and I feel sure there are suitable people in SA that can help. One solution therefore is probably to ship the whole engine (less auxiliaries) or the whole bottom end at least to us.
If you are rebuilding using Porsche bottom end crankcases etc then cylinder heads should still require skimming and overhauls and the work required cleaning and rebuilding adds significantly to the final cost.
There are also alternative suppliers but I think it is fair to say that no one else has carried out as much research, test and development as us, no one else offers the modifications and the range of alternative choices and no one else has their own internal precision machine shop in which they can carry out all the work "in house" - so although you are free to compare what we do with others - it must at least be worthwhile making contact with us as well.
There are inevitably other sources of engine rebuilds. Some have typically tried to copy what we do, others provide inferior solutions (that often backfire resulting in us rebuilding them again properly). Most offer iron or steel liners and while the manufacturers of the basic liners are often providing a very good product - the final machining and the method of fitting them varies with each supplier and many fail due to the problems that resulted in Porsche themselves abandoning the solution over 40 years ago (together with most high performance sports car manufacturers who's engines have such large cylinder bores).
If you are using your engine only for racing then steel liners can be suitable because the engines are only ever running flat out but for the combination of road use varying so much they rarely can fulfil all the variations in temperatures and expansion rates.
However for road use and racing - there is in our opinion nothing better than an alloy liner with a Nikasil finish (which we use together with Porsche for all their air cooled engines since the '70's and their Turbo and GT3 models - without problems) and because we have invested in CNC machinery to carry out the process of fitting them we can pretty well price match the cost of all the other alternatives available anyway.
For further information please refer to our web site www.hartech.org (and the buyers guide sections 4 and 5) or contact us via the contact details revealed.
Good luck,
Baz
Just in case it helps - we have successfully supplied rebuilt engines, bottom ends and crankcases to customers all over the World and because they incorporate different internals and various subtle but important modifications - they have proven extremely reliable. The cost is also significantly less than the replacements you have mentioned (even with shipping) - however the down side is that you would need a reliable source to remove and re-fit the engine and/or strip and rebuild it.
No one else Worldwide has had a problem doing this - and I feel sure there are suitable people in SA that can help. One solution therefore is probably to ship the whole engine (less auxiliaries) or the whole bottom end at least to us.
If you are rebuilding using Porsche bottom end crankcases etc then cylinder heads should still require skimming and overhauls and the work required cleaning and rebuilding adds significantly to the final cost.
There are also alternative suppliers but I think it is fair to say that no one else has carried out as much research, test and development as us, no one else offers the modifications and the range of alternative choices and no one else has their own internal precision machine shop in which they can carry out all the work "in house" - so although you are free to compare what we do with others - it must at least be worthwhile making contact with us as well.
There are inevitably other sources of engine rebuilds. Some have typically tried to copy what we do, others provide inferior solutions (that often backfire resulting in us rebuilding them again properly). Most offer iron or steel liners and while the manufacturers of the basic liners are often providing a very good product - the final machining and the method of fitting them varies with each supplier and many fail due to the problems that resulted in Porsche themselves abandoning the solution over 40 years ago (together with most high performance sports car manufacturers who's engines have such large cylinder bores).
If you are using your engine only for racing then steel liners can be suitable because the engines are only ever running flat out but for the combination of road use varying so much they rarely can fulfil all the variations in temperatures and expansion rates.
However for road use and racing - there is in our opinion nothing better than an alloy liner with a Nikasil finish (which we use together with Porsche for all their air cooled engines since the '70's and their Turbo and GT3 models - without problems) and because we have invested in CNC machinery to carry out the process of fitting them we can pretty well price match the cost of all the other alternatives available anyway.
For further information please refer to our web site www.hartech.org (and the buyers guide sections 4 and 5) or contact us via the contact details revealed.
Good luck,
Baz
mollytherocker said:
Magic919 said:
The stats from the poll are pretty meaningless.
They are no worse than anything else.And those that do, take the time out to search the Porsche forum and write that their engines are 100% okay? Or, the majority of owners who have an issue, search Google, then complain on the Pistonheads forum?
25% is a ridiculous figure.
I could say that there are 6 x 964's for sale, all advertised with engine work. That would equate to a 100% engine problem.
Unless these figures are linked to cars sold data, they're meaningless.
fastgerman said:
I could say that there are 6 x 964's for sale, all advertised with engine work. That would equate to a 100% engine problem.
What has this got to do with 996/997 engine reliability?1 in 4 seems about correct to me, with the remainder seemingly only a matter of time.
Exception is the 997.2 engine which seems far more reliable thus far.
Helicopter123 said:
What has this got to do with 996/997 engine reliability?
1 in 4 seems about correct to me, with the remainder seemingly only a matter of time.
Exception is the 997.2 engine which seems far more reliable thus far.
1 in 4 seems about right to you? What are basing this figure on? The majority seem to think a figure of 1 in 20 is probably about right.1 in 4 seems about correct to me, with the remainder seemingly only a matter of time.
Exception is the 997.2 engine which seems far more reliable thus far.
Yes, they will all fail in time, no different to most other engines then really. There are plenty of examples that have covered 150k+ mls without issue.
It seems that some bore scoring takes perhaps over 10K before it gets bad enough to be obvious so many cars that have the problem only reveal it when they are boroscoped.
Going back a couple of years many Sports car sales outlets were selling cars that turned out to have bore scoring discovered by the new owner immediately upon getting it checked over after buying it and so under the law the seller had to pay for a repair = no profit.
Since then many have protected themselves by having a boroscope check before buying and those that have reported to us suggest about one in three has bore scoring already despite showing no other symptoms.
Now a couple of years on more will have the problem even though the owners may not have experienced the consequences yet.
I agree that it is almost impossible to assess exactly how many suffer since so many already have the problem and don't know it.
I also suspect that a good many offered for sale to the trade are from owners who have noticed the slight changes in oil consumption or exhaust blackening and had the car checked somewhere else before deciding to sell it instead of fixing it - so the proportions are probably less than that.
Several factors can combine to make it happen sooner or later.
It depends on the difference between the dispersion, size and density of silicon in the Lokasil preform, the bonding quality and the aluminium flow during casting.
When the cylinder is honed there is a random number of minute silicon particles that are either entrapped by the aluminium in a sort of dovetail so they cannot easily fall out, some others that are half honed away and so are relying on the bonding to remain where they are and some others are already honed away so that very little is retained in the aluminium and can easily fall out over time. When they do they interfere with the piston coating and can puncture or tear it before being taken away by the oil in the engine.
The longer the car is driven and the hotter the internals - the thinner the oil and the smaller the gap between the piston face and the cylinder bore - so the more inclined the lose particles are to damaging the bore and piston. The greater the torque delivered the harder the piston face pushes against the cylinder wall and the more oil it squeezes out from the gap between the piston and the cylinder bore and hence the more the silicon particles can grind into the piston and cylinder surface.
The hotter the coolant the thinner the oil and the smaller the oil film.
As all the cylinders migrate oval in time the surface temperature of the piston gradually runs hotter (since it is the oil film that largely conducts the heat to the cylinder block at the piston surface).
From this you can see that driver style, oil viscosity, age and mileage, quality of original product etc all combine to vary the failure mileages and outcomes.
I agree that all will probably need rebuilding in time and when they are changing the bore material is a good change.
Nikasil does not have lose silicon particles and is not only plated onto the bore but also to each adjacent part such that it forms a thin tube bonded to the cylinder and offering good lubrication and long life.
Steel and iron can also work but although many of the base liners on offer are perfectly good as material the design and fitting is usually left to small reconditioning shops not as familiar with the engineering problems that can occur with this type of application and so quite a lot fail. Many use boring machines that are not manufactured to provide extremely accurate set flange depths from which to support the liner flanges either.
The differential expansion rates of aluminium and a ferrous material are part of this problem as is the cold clearances necessary to keep an aluminium piston at the right clearance with the cylinder bore with widely different heat conditions between doddering around and flat out motoring. For racing there is only ever flat out motoring so the problems limit themselves to deck height control with the differential expansion. Traditional head gaskets designed for ferrous liners usually had thick compliant designs (or separate special seals) to allow for these variations but the Porsche engine has a head gasket with three pieces of thin metal with minor depressions and a very thin plastic coating that cannot tolerate even small changes in the flatness of the surface.
So although the people that make these various types of liners generally provide a quality product we find all the different sizes and shapes they are subsequently machined to and the different methods of fitting them result in some failing (through no fault of the original liner manufacturer).
To try and encourage owners to use the solution that has been used by Porsche, McLaren etc for many years without any problems - we have invested in manufacturing equipment to lower our costs for this high quality alternative to reach or get very close to the cost of ferrous alternatives anyway - making the choice a no brainer for those who understand the issues. While we are carrying out this work the same equipment creates other changes that we have researched to improve longevity.
We refuse to supply these liners for others to fit and will only consider it for overseas markets with partners who have firstly used our own supply and then entered into technical agreements that ensure quality control and after we have vetted their machining facilities and quality control systems. So far no one has come up to scratch and by this stance we ensure all our blocks have liners fitted bu us to our design resulting in no problems with any of these issues. We do however have partners in Europe who we supply remanufactured blocks to and now this is extending to the USA etc (and anyway we have supplied remanufactured blocks, engines and bottom ends Worldwide as far as Australia and Korea without problems). We think the design of the liner, tolerances and fitting are a very important part of the whole process and that this is where some competitors create problems by using other sources to carry out machining and fitting their own way.
I hope this all helps those trying to decide what to do when they experience bore scoring problems.
Baz
Going back a couple of years many Sports car sales outlets were selling cars that turned out to have bore scoring discovered by the new owner immediately upon getting it checked over after buying it and so under the law the seller had to pay for a repair = no profit.
Since then many have protected themselves by having a boroscope check before buying and those that have reported to us suggest about one in three has bore scoring already despite showing no other symptoms.
Now a couple of years on more will have the problem even though the owners may not have experienced the consequences yet.
I agree that it is almost impossible to assess exactly how many suffer since so many already have the problem and don't know it.
I also suspect that a good many offered for sale to the trade are from owners who have noticed the slight changes in oil consumption or exhaust blackening and had the car checked somewhere else before deciding to sell it instead of fixing it - so the proportions are probably less than that.
Several factors can combine to make it happen sooner or later.
It depends on the difference between the dispersion, size and density of silicon in the Lokasil preform, the bonding quality and the aluminium flow during casting.
When the cylinder is honed there is a random number of minute silicon particles that are either entrapped by the aluminium in a sort of dovetail so they cannot easily fall out, some others that are half honed away and so are relying on the bonding to remain where they are and some others are already honed away so that very little is retained in the aluminium and can easily fall out over time. When they do they interfere with the piston coating and can puncture or tear it before being taken away by the oil in the engine.
The longer the car is driven and the hotter the internals - the thinner the oil and the smaller the gap between the piston face and the cylinder bore - so the more inclined the lose particles are to damaging the bore and piston. The greater the torque delivered the harder the piston face pushes against the cylinder wall and the more oil it squeezes out from the gap between the piston and the cylinder bore and hence the more the silicon particles can grind into the piston and cylinder surface.
The hotter the coolant the thinner the oil and the smaller the oil film.
As all the cylinders migrate oval in time the surface temperature of the piston gradually runs hotter (since it is the oil film that largely conducts the heat to the cylinder block at the piston surface).
From this you can see that driver style, oil viscosity, age and mileage, quality of original product etc all combine to vary the failure mileages and outcomes.
I agree that all will probably need rebuilding in time and when they are changing the bore material is a good change.
Nikasil does not have lose silicon particles and is not only plated onto the bore but also to each adjacent part such that it forms a thin tube bonded to the cylinder and offering good lubrication and long life.
Steel and iron can also work but although many of the base liners on offer are perfectly good as material the design and fitting is usually left to small reconditioning shops not as familiar with the engineering problems that can occur with this type of application and so quite a lot fail. Many use boring machines that are not manufactured to provide extremely accurate set flange depths from which to support the liner flanges either.
The differential expansion rates of aluminium and a ferrous material are part of this problem as is the cold clearances necessary to keep an aluminium piston at the right clearance with the cylinder bore with widely different heat conditions between doddering around and flat out motoring. For racing there is only ever flat out motoring so the problems limit themselves to deck height control with the differential expansion. Traditional head gaskets designed for ferrous liners usually had thick compliant designs (or separate special seals) to allow for these variations but the Porsche engine has a head gasket with three pieces of thin metal with minor depressions and a very thin plastic coating that cannot tolerate even small changes in the flatness of the surface.
So although the people that make these various types of liners generally provide a quality product we find all the different sizes and shapes they are subsequently machined to and the different methods of fitting them result in some failing (through no fault of the original liner manufacturer).
To try and encourage owners to use the solution that has been used by Porsche, McLaren etc for many years without any problems - we have invested in manufacturing equipment to lower our costs for this high quality alternative to reach or get very close to the cost of ferrous alternatives anyway - making the choice a no brainer for those who understand the issues. While we are carrying out this work the same equipment creates other changes that we have researched to improve longevity.
We refuse to supply these liners for others to fit and will only consider it for overseas markets with partners who have firstly used our own supply and then entered into technical agreements that ensure quality control and after we have vetted their machining facilities and quality control systems. So far no one has come up to scratch and by this stance we ensure all our blocks have liners fitted bu us to our design resulting in no problems with any of these issues. We do however have partners in Europe who we supply remanufactured blocks to and now this is extending to the USA etc (and anyway we have supplied remanufactured blocks, engines and bottom ends Worldwide as far as Australia and Korea without problems). We think the design of the liner, tolerances and fitting are a very important part of the whole process and that this is where some competitors create problems by using other sources to carry out machining and fitting their own way.
I hope this all helps those trying to decide what to do when they experience bore scoring problems.
Baz
Regarding the 25% figure and as just posted on a similar thread, see the below quotes from the guru of Porsche inspections; Peter Morgan:
The following quotes I also like:
Re:IMS - 'This issue would not stop me buying a car, if it was otherwise on the button. Many independent specialists now offer strengthened IMS bearings to retrofit. Replacement at clutch change time reduces the relative labour cost involved and can improve the desirability of a car at resale.'
Re:Bore scoring - 'These failures are real, but we must emphasise that they are a relatively low percentage of all the Carrera engine Porsches out there. More than a few reputable independent dealers I have spoken to say that they haven't seen a bore scored 996/997/Boxster or Cayman for years (and that is only partly down to their expertise). It should not put you off buying one of these cars, assuming you do your homework and know the obvious failure signs.'
Would 25% = a low percentage? I don't think so!
http://www.porscheinspections.com/qanda.php
The following quotes I also like:
Re:IMS - 'This issue would not stop me buying a car, if it was otherwise on the button. Many independent specialists now offer strengthened IMS bearings to retrofit. Replacement at clutch change time reduces the relative labour cost involved and can improve the desirability of a car at resale.'
Re:Bore scoring - 'These failures are real, but we must emphasise that they are a relatively low percentage of all the Carrera engine Porsches out there. More than a few reputable independent dealers I have spoken to say that they haven't seen a bore scored 996/997/Boxster or Cayman for years (and that is only partly down to their expertise). It should not put you off buying one of these cars, assuming you do your homework and know the obvious failure signs.'
Would 25% = a low percentage? I don't think so!
http://www.porscheinspections.com/qanda.php
fastgerman said:
Would 25% = a low percentage? I don't think so!
It all depends what you are measuring and over what period. I can assure you that these engines have a 100% failure rate, as do all engines. No engine lasts forever.My view without any real stats is that the M96 and M97 are likely to fail sooner than most modern engines.
The only thing that matters to the buyer though is - 'Will it fail during my ownership?'. Thats the hard one to answer.
You could say that the longer you keep the car, the more likely it will fail, cetainly bore scoring is fairly inevitable eventually. But if you carry out certain preventative measures and adjust your driving style you could probably reduce it significantly.
There are many other variables too of course, like the fact that many cars for sale are being sold as they have some signs of impending issues.
hey guys.
sorry if this a re-post but the IMS engine failure rate percentage was stated in the class action lawsuit lodged in California against Porsche USA. The US failure rate was against a much larger sample size than what we would see in the UK.
The agreed figure was in the 8-10% region of all affected Porsche models sold in the years 2001-2005.
This was the percentage figure used in court after a long battle with PCNA and 4000 pages of evidence were reviewed.
I have seen figures as high as 25-30% quoted but those kind of numbers were never stated in court to my knowledge. As the litigation was resolved towards Q3 2012, the statistics on failure rates from the preceding eras would have been well known by this point and submitted as evidence by PCNA.
The cars excluded from the litigation were GT2, GT3 and Turbo.
http://www.imsporschesettlement.com/wp-content/med...
sorry if this a re-post but the IMS engine failure rate percentage was stated in the class action lawsuit lodged in California against Porsche USA. The US failure rate was against a much larger sample size than what we would see in the UK.
The agreed figure was in the 8-10% region of all affected Porsche models sold in the years 2001-2005.
This was the percentage figure used in court after a long battle with PCNA and 4000 pages of evidence were reviewed.
I have seen figures as high as 25-30% quoted but those kind of numbers were never stated in court to my knowledge. As the litigation was resolved towards Q3 2012, the statistics on failure rates from the preceding eras would have been well known by this point and submitted as evidence by PCNA.
The cars excluded from the litigation were GT2, GT3 and Turbo.
http://www.imsporschesettlement.com/wp-content/med...
According to the article in GT Purely Porsche March Issue by respected technical motoring journalist Peter Morgan - numbers with bore scoring quoted by other dealers range from 0.2% to 50% which seems confusing until you read more about what figures they refer to.
We are thinking in terms of cars in their reasonable lifetime either from new to now or say up to 150K or so.
One dealer says 50% of those offered to them for sale (probably reflecting the knowledge owners already have to find clues to having the problem and trying to dispose of the vehicle - so very much buyer beware! We would say 30% (but then sellers know we will check them first).
One Service centre says 1 in every 50 or 60 they see in a month. If you take your car there only once/year that still means over a 10 year cycle 10 in every 50 or 60 which is still 20% or so.
Another says less than 10% - but they would see less that have actually scored as we alone are fixing more than 3/week that come here for the check once the owner suspects the problem in readiness for a rebuild. This suggests it should therefore be more than 10%.
Another says less than 0.2% (one in 500) - and I would question this as all the other statistics seem to point to the numbers being between 10 and 20% over a 10 year cycle (and don't forget they are unlikely to fail in the first few years, many have scoring but don't know it yet and many will still get it in the next 5 years - so over 15 years I would suggest 15% or so seems fair. Some variation may reflect the age of cars a particular dealer sees or the mileages that owners in that area of the UK typically cover.
That is not an insignificant number (over 3000 in the UK alone) of which we have already fixed hundreds (although not all with 6 new cylinders so some may eventually return for others to be repaired as well).
I expect numbers and percentages of the remaining cars to go up as the cars age and there is a suspicion that lower numbers of Gen 2 may well eventually reach a point where they need similar treatment (only time will tell).
Best protection must be our Maintenance Plan that services and repairs your car for routine and wear and tear items free or at a parts only charge including engines and has no age, cost or mileage limit!
Baz
We are thinking in terms of cars in their reasonable lifetime either from new to now or say up to 150K or so.
One dealer says 50% of those offered to them for sale (probably reflecting the knowledge owners already have to find clues to having the problem and trying to dispose of the vehicle - so very much buyer beware! We would say 30% (but then sellers know we will check them first).
One Service centre says 1 in every 50 or 60 they see in a month. If you take your car there only once/year that still means over a 10 year cycle 10 in every 50 or 60 which is still 20% or so.
Another says less than 10% - but they would see less that have actually scored as we alone are fixing more than 3/week that come here for the check once the owner suspects the problem in readiness for a rebuild. This suggests it should therefore be more than 10%.
Another says less than 0.2% (one in 500) - and I would question this as all the other statistics seem to point to the numbers being between 10 and 20% over a 10 year cycle (and don't forget they are unlikely to fail in the first few years, many have scoring but don't know it yet and many will still get it in the next 5 years - so over 15 years I would suggest 15% or so seems fair. Some variation may reflect the age of cars a particular dealer sees or the mileages that owners in that area of the UK typically cover.
That is not an insignificant number (over 3000 in the UK alone) of which we have already fixed hundreds (although not all with 6 new cylinders so some may eventually return for others to be repaired as well).
I expect numbers and percentages of the remaining cars to go up as the cars age and there is a suspicion that lower numbers of Gen 2 may well eventually reach a point where they need similar treatment (only time will tell).
Best protection must be our Maintenance Plan that services and repairs your car for routine and wear and tear items free or at a parts only charge including engines and has no age, cost or mileage limit!
Baz
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