Engine Failure 2003 996 C4S 118,000 miles, Gearbox failure and replace

[norton-sp]

yes..very interesting links..the "break in secrets" reflect my experience. i remember a few times in the past, friends and other motorcycle riders wondering why my motorcycles seemed to perform better, run smoother and use no oil...especially my 6 cylinder honda which ran as smooth as an electric motor and performed/ran better than my friends bike which was the same model just much newer. (and run-in according to the manual)

i must admit i was pretty facinated by those "run in secrets"...a great link.

cheers

kelvin

[Johnnyceesred]

Porsche GB have acknowledged receipt of the report and have said they will respond within 30 days.

Rgds

John

[Johnnyceesred]

Engine's back in. Slight delay due to bottom hose in later 996 engine being a push-fit (as used on 997 engines as well) rather than traditional hose-clip fixing. New hose is on it's way. Should be finished early next week.

Rgds

John

[Johnnyceesred]

Engine's back in. Slight delay due to bottom hose in later 996 engine being a push-fit (as used on 997 engines as well) rather than traditional hose-clip fixing. New hose is on it's way. Should be finished early next week.

Rgds

John

New hose fitted, engine warmed up, re-filled with anti-freeze, road tested and.........................................offside radiator leaking!!!!!!! :cursing:

Two new rads on the way, hopefully fitting Thursday/Friday this week. Fingers crossed I'll be back on the road at the weekend. Good point is that I got the 2 new rads for £267 less than the Porsche GB RRP and the peace of mind that the cooling system's OK. The specialist says that many people put in new rads with a new engine anyway.

Rgds

John

[Lee Quave]

John,

Have you gotten your car back? You must have the patients of a saint. Have you found out what “upgrades” have been done to the replacement engines as compared to the original M96? I get no response from PCNA and the local service tech seems to be in the dark. I guess Porsche wants it that way!

Lee

[Johnnyceesred]

John,

Have you gotten your car back? You must have the patients of a saint. Have you found out what “upgrades” have been done to the replacement engines as compared to the original M96? I get no response from PCNA and the local service tech seems to be in the dark. I guess Porsche wants it that way!

Lee

Hi Lee,

To quote the old Canned Heat song "I'm on the Road Again" :drive: :jump: .

Got the car back on Saturday but within 200 yards of leaving the specialist "CEL - Drive to Workshop" came on :cursing: . Went to my most local OPC today and they diagnosed a faulty Oxygen Sensor. So £233 more spent and everything now OK :clapping:

I also rang Porsche GB today and was told that they have put a letter in the post. The guy I spoke to couldn't/wouldn't tell me what it says, just "read it and make your decisions based on what is says" :unsure: So watch this space and fingers crossed for when the post drops through the letterbox.

Money spent: -

Engine - £7,325.25

Labor, new hoses, anti-freeze, rear gearbox mounting (old one had broken rubber shock absorber) etc - £3,119.02 (includes taking out old engine and re-building to return to Porsche GB)

New radiators - £400.00

Oxygen Sensor and diagnostics - £233.33

RAC Report - £94.00

Grand total - £11,171.60

Rgds

John

Edited February 20, 2007 by Johnnyceesred

[viper501]

With the exchange rate, you could have almost bought another 996 here in the States.

[PeterK]

With the exchange rate, you could have almost bought another 996 here in the States.

Thankfully, in US we would have to pay the same number for these repairs, but it would be in $

[norton-sp]

John,

Have you gotten your car back? You must have the patients of a saint. Have you found out what “upgrades” have been done to the replacement engines as compared to the original M96? I get no response from PCNA and the local service tech seems to be in the dark. I guess Porsche wants it that way!

Lee

Hi Lee,

To quote the old Canned Heat song "Back on the Road Again" :drive: :jump: .

Got the car back on Saturday but within 200 yards of leaving the specialist "CEL - Drive to Workshop" came on :cursing: . Went to my most local OPC today and they diagnosed a faulty Oxygen Sensor. So £233 more spent and everything now OK :clapping:

I also rang Porsche GB today and was told that they have put a letter in the post. The guy I spoke to couldn't/wouldn't tell me what it says, just "read it and make your decisions based on what is says" :unsure: So watch this space and fingers crossed for when the post drops through the letterbox.

Money spent: -

Engine - £7,325.25

Labor, new hoses, anti-freeze, rear gearbox mounting (old one had broken rubber shock absorber) etc - £3,119.02 (includes taking out old engine and re-building to return to Porsche GB)

New radiators - £400.00

Oxygen Sensor and diagnostics - £233.33

RAC Report - £94.00

Grand total - £11,171.60

Rgds

John

jesus!!! poor u, im flabergasted! (love that word) ... i paid just over 11,000 EUROS for my new engine, all inclusive...the only extra part i had to have installed was one new exhaust clamp for the end pipe, which they didnt charge me for because i moaned.

i was real upset about that because of the prices i saw qouted here for an engine change in the US where about the same in euros as in USD...no-one could tell me why an engine is cheaper in the US even considering it has to get there!! (or do they build them in mexico? that would explain some things :unsure: ) you obviously had to pay for the dismanteling/rebuilding of your old engine which makes it more costly, but it still looks like porsche just charge the same price irrespective of the currency or exchange rate!! :rolleyes: my tip: get it done in poland next time :lightbulb:

[Johnnyceesred]

John,

Have you gotten your car back? You must have the patients of a saint. Have you found out what “upgrades” have been done to the replacement engines as compared to the original M96? I get no response from PCNA and the local service tech seems to be in the dark. I guess Porsche wants it that way!

Lee

Hi Lee,

To quote the old Canned Heat song "Back on the Road Again" :drive: :jump: .

Got the car back on Saturday but within 200 yards of leaving the specialist "CEL - Drive to Workshop" came on :cursing: . Went to my most local OPC today and they diagnosed a faulty Oxygen Sensor. So £233 more spent and everything now OK :clapping:

I also rang Porsche GB today and was told that they have put a letter in the post. The guy I spoke to couldn't/wouldn't tell me what it says, just "read it and make your decisions based on what is says" :unsure: So watch this space and fingers crossed for when the post drops through the letterbox.

Money spent: -

Engine - £7,325.25

Labor, new hoses, anti-freeze, rear gearbox mounting (old one had broken rubber shock absorber) etc - £3,119.02 (includes taking out old engine and re-building to return to Porsche GB)

New radiators - £400.00

Oxygen Sensor and diagnostics - £233.33

RAC Report - £94.00

Grand total - £11,171.60

Rgds

John

jesus!!! poor u, im flabergasted! (love that word) ... i paid just over 11,000 EUROS for my new engine, all inclusive...the only extra part i had to have installed was one new exhaust clamp for the end pipe, which they didnt charge me for because i moaned.

i was real upset about that because of the prices i saw qouted here for an engine change in the US where about the same in euros as in USD...no-one could tell me why an engine is cheaper in the US even considering it has to get there!! (or do they build them in mexico? that would explain some things :unsure: ) you obviously had to pay for the dismanteling/rebuilding of your old engine which makes it more costly, but it still looks like porsche just charge the same price irrespective of the currency or exchange rate!! :rolleyes: my tip: get it done in poland next time :lightbulb:

Hi,

Re your love of "Flabbergasted" take a look at http://blogs.ipona.com/frog/archive/2004/11/25/471.aspx

On a more serious note, I had Porsche GB e-mail me their latest written response which is missing some fundamental facts so I need to correct that situation and supply some further information regarding the reports.

The actual labor costs at the independent were were £2,749.50. The quote I got from the OPC for then same work was £6,580.

Rgds

John

[Johnnyceesred]

With the exchange rate, you could have almost bought another 996 here in the States.

Viper, Peter

It's like the US software I sell in the UK. The vendors ask for the same number in sterling as the US $ price.

Rgds

John

[PeterK]

John,

Have you gotten your car back? You must have the patients of a saint. Have you found out what “upgrades” have been done to the replacement engines as compared to the original M96? I get no response from PCNA and the local service tech seems to be in the dark. I guess Porsche wants it that way!

Lee

Hi Lee,

To quote the old Canned Heat song "Back on the Road Again" :drive: :jump: .

Got the car back on Saturday but within 200 yards of leaving the specialist "CEL - Drive to Workshop" came on :cursing: . Went to my most local OPC today and they diagnosed a faulty Oxygen Sensor. So £233 more spent and everything now OK :clapping:

I also rang Porsche GB today and was told that they have put a letter in the post. The guy I spoke to couldn't/wouldn't tell me what it says, just "read it and make your decisions based on what is says" :unsure: So watch this space and fingers crossed for when the post drops through the letterbox.

Money spent: -

Engine - £7,325.25

Labor, new hoses, anti-freeze, rear gearbox mounting (old one had broken rubber shock absorber) etc - £3,119.02 (includes taking out old engine and re-building to return to Porsche GB)

New radiators - £400.00

Oxygen Sensor and diagnostics - £233.33

RAC Report - £94.00

Grand total - £11,171.60

Rgds

John

jesus!!! poor u, im flabergasted! (love that word) ... i paid just over 11,000 EUROS for my new engine, all inclusive...the only extra part i had to have installed was one new exhaust clamp for the end pipe, which they didnt charge me for because i moaned.

i was real upset about that because of the prices i saw qouted here for an engine change in the US where about the same in euros as in USD...no-one could tell me why an engine is cheaper in the US even considering it has to get there!! (or do they build them in mexico? that would explain some things :unsure: ) you obviously had to pay for the dismanteling/rebuilding of your old engine which makes it more costly, but it still looks like porsche just charge the same price irrespective of the currency or exchange rate!! :rolleyes: my tip: get it done in poland next time :lightbulb:

Actually, people from mexico take their cars to Texas porsche dealers because major parts are more expensive in Mexico.

I think it is just supply and demand. US lux car market is very competitive. Lexus, BMW, Merc are all fighting for the same segment. If porsche decides to charge $20K for a new engine, that will influence the used car market and introduce a major downside drift to resale. This in turn will drop the leasing residuals for the new cars and thus increase the costs of leasing, which will result in less cars being purchased.

UK car market is just generally quite krazy for some reason. I think comparable car models are selling for the same amount in $ vs. f.

Edited February 21, 2007 by PeterK

[Johnnyceesred]

Done around 700 miles since new engine fit and O2 sensor replacement, everything feels and sounds good. Will change oil at 1,000 miles.

I'll be delivering a copy of the metallurgist's report to Porsche GB tomorrow (Friday) which they said would help my position. It cost me £152.75 including tax.

For those of us in the UK, there's a link on the Department of Trade and Industry web site www.dti.gov.uk regarding the Sale of Goods Act 1979 that states that one of the points to consider when considering a claim is durability and safety. I'll post the link later today.

I'll update when there's more news.

Rgds

John

[Johnnyceesred]

Useful links for the UK

http://www.dti.gov.uk/consumers/fact-sheet...9010_print.html

http://www.dti.gov.uk/consumers/fact-sheets/page24700.html

http://www.dti.gov.uk/consumers/fact-sheets/page9010.html

I guess there are equivalents in the US for consumer protection?

Rgds

John

Edited March 1, 2007 by Johnnyceesred

[Johnnyceesred]

Spoke to Porsche GB today. I should get their reply to the metallurgy report next week. I've agreed to call them Wednesday if I don't hear anything before.

Oil change done on new engine at just over 1,000 miles. Starting to use more revs for the next 500-1,000 miles.

Rgds

John

[viper501]

John,

Thanks again for the updates. Will be keeping an eye on this as it develops.

[Johnnyceesred]

John,

Thanks again for the updates. Will be keeping an eye on this as it develops.

Hi Viper,

I picked up the latest letter from Porsche GB last Friday. They're still refusing my claim and stated that they consider the matter closed. I've informed them that I do not and have today e-mailed Dr.Wiedeking President and CEO of Porsche AG with details of my complaint and requested his assistance in resolving the situation.

According to his PA he should be back on Thursday so we'll see what develops.

Rgds

John

[CosmosC4S]

Good Luck John, I admire your strong will on this matter.

No matter what happens in the end, at least you could settle, knowing that you gave it a good fight.

I hope you win your case, all the best!

[Johnnyceesred]

Good Luck John, I admire your strong will on this matter.

No matter what happens in the end, at least you could settle, knowing that you gave it a good fight.

I hope you win your case, all the best!

Hi Cosmos,

Thanks for your comments. I'll keep thread updated.

Rgds

John

[Johnnyceesred]

Good Luck John, I admire your strong will on this matter.

No matter what happens in the end, at least you could settle, knowing that you gave it a good fight.

I hope you win your case, all the best!

Hi Cosmos,

Dr. Wiedeking apparently just passed my e-mail on to the Customer Commitment team in Germany and so I'm corresponding with them as well as the UK Customer Assistance Team.

For some reason (and I can guess what that is) they are focusing (incorrectly) on the misfire as being the basis of my complaint and claim and their continuing rejection and not the sub-standard crank cradle. They have not commented about the quality issue at all which I think says a lot.

I have today passed the correspondence on to two well-known motoring magazines in the UK to see if they think the situation is news-worthy and if they are interested assisting in my cause.

Whilst I've got the metallurgy specialist's report on PDF now, I'm hesistant to publish it too widely in case in jeopardises my situation right now. If I get to the stage where I feel that I'm left with no choice then I'll consider things again.

Kind regards

John

Edited April 12, 2007 by Johnnyceesred

[CosmosC4S]

You're right, don't make hasty moves now that may jeopardise your case.

Porsche is working on it now and you don't know what their decision is yet, there is still hope.

But if you get this published now and upset them, that might backfire on you!

I say, Hold on to your cards for now...

[Johnnyceesred]

You're right, don't make hasty moves now that may jeopardise your case.

Porsche is working on it now and you don't know what their decision is yet, there is still hope.

But if you get this published now and upset them, that might backfire on you!

I say, Hold on to your cards for now...

Hi Cosmos,

Thanks for your supportive comments. I've also sent the photos and correspondence to the solicitor my employers use to get his assessment of what I've done so far and his recommendations of the next steps.

Since I've had the new engine there's been no recurrence of the misfire so I can safely say it was related to the original engine and not to any other electricals or connections from other parts of the car to the engine.

I'll keep things updated.

Best regards

John

Edited April 12, 2007 by Johnnyceesred

[Johnnyceesred]

Gearbox failure and replacement at 125,300 miles!!!!!!

Hi all,

There's not been much to update since my last post save 2 points: -

1. As you can see from the title above, my gearbox failed and was replaced. It developed a severe whining noise at around 2,500-3,000 rpm and this was particularly noticeable when manually changing from 3rd to 2nd gear (it's Tiptronic S). I took it to the local OPC whose technician did a test drive and concluded a new gearbox was required. Had that fitted June 7. Whilst fitting the gearbox they also noticed that the rubber mounting on the front-to-rear prop shaft had split and that the only solution was a new prop shaft (Porsche do not supply the rubber mounting separately). So that was fitted June 16. End user cost for these parts and labour would have been around £9,300. The good news is I took out a year's extended warranty on 1st May at around 124,300 miles so all costs were covered by the warranty. That was £895 well spent.

2. I've got the local Trading Standards Office (part of the UK Government's Office of Fair Trading Department) communicating with the OPC that sold me the car and Porsche Cars GB, to see if they can progress my claim for compensation against the cost of the replacement engine etc. I'll update the thread with any news that I can publish.

Regards

John

[jmj996]

Gearbox failure and replacement at 125,300 miles!!!!!!

Hi all,

There's not been much to update since my last post save 2 points: -

1. As you can see from the title above, my gearbox failed and was replaced. It developed a severe whining noise at around 2,500-3,000 rpm and this was particularly noticeable when manually changing from 3rd to 2nd gear (it's Tiptronic S). I took it to the local OPC whose technician did a test drive and concluded a new gearbox was required. Had that fitted June 7. Whilst fitting the gearbox they also noticed that the rubber mounting on the front-to-rear prop shaft had split and that the only solution was a new prop shaft (Porsche do not supply the rubber mounting separately). So that was fitted June 16. End user cost for these parts and labour would have been around £9,300. The good news is I took out a year's extended warranty on 1st May at around 124,300 miles so all costs were covered by the warranty. That was £895 well spent.

2. I've got the local Trading Standards Office (part of the UK Government's Office of Fair Trading Department) communicating with the OPC that sold me the car and Porsche Cars GB, to see if they can progress my claim for compensation against the cost of the replacement engine etc. I'll update the thread with any news that I can publish.

Regards

John

John,

This has been a fascinating thread. I am really sorry to hear about your problems and I hope that I never have to go through the same thing. First, I'll get straight to the point, then I'll explain. Based on the information we have (and I'm kind of making a big assumption that I have all of the key, relevant information that the shop had when they decided to disassemble it) I believe you have a stronger case against the shop that performed the initial diagnosis than you do against Porsche. I believe that the engine disassembly was premature and was not the appropriate course of action given the evidence. I don't think they did enough to determine that the disassembly was necessary before diving in. I think that they only did it because they couldn't find the source of the problem and had nothing else to follow up on besides a small piece of metal. It was the right decision to eventually replace it *after* it was already disassembled and *potential* trouble parts were identified, but it never needed to get that far in the first place. That probably wouldn't have been necessary for at least another 10k-30k miles.

To try to briefly summarize all that has already been reported with respect to the sequence of events that led to the engine replacement:

1) Engine is running rough. Problem comes and goes, and shifts from one side to another. Several attempts to troubleshoot it don't lead to a solution, but a small piece of metal is found in the case.

2) Engine is disassembled as a result of finding the metal to see if that is the source of the problem. There are definitely a few areas of concern with regard to structural integrity, but catastrophic mechanical failure has not occurred as a result of those issues, and there were no huge metal particle problems (the contents of the oil filter is the biggest factor to me).

3) Ultimately, the source of the misfiring is never determined, but because of the concerns with the structural integrity and its high mileage, the engine is deemed not worth all the trouble to reassemble and restart the troubleshooting process, so the engine is replaced.

Here is the predicament:

1) The engine did not actually experience catastrophic failure. It had a fairly uncommon problem, but it was not self-destructing.

2) The structural issues that were identified do not lend to an explanation of the engine woes. I can't even justify a very loose correlation.

3) The source of the problem that contributed to the engine woes was never identified.

4) The engine was replaced without having experienced a catastrophic failure or identifying the source of the problem that put it in the shop in the first place.

Given all of this, it will not be possible to prove that the structural problem that is the focus of the metallurgical examination would have been the source of the engine's ultimate demise. Who's to say that something else wouldn't have eventually given way first - a crank bearing, a piston, valve springs - all parts that are more likely to fail and not as likely to suggest that Porsche should be responsible for replacing the engine (or at least a partial offer).

I'll bet that Porsche has performed numerous FMEA's (Failure Mode and Effect Analysis) on the failed engines that they've taken back. Since Porsche does not release statistics or other detailed information about engine failures, we will never know if any of those FMEA's pointed to the same part that is the focus of your investigation (though I would like to hear from any mechanics of Porsche's water-cooled engines that have identified this as the source of failure in an engine they removed). If by some chance they had seen that in another engine, the best conclusion they can draw is that this part has some probability of being the ultimate cause of failure, but that it hasn't failed yet and there's no way to prove that something else wouldn't have gone first.

You have many valid points in your case. The piece in question probably never should have been used. I've read about another process Porsche implemented to retrofit new sleeves into new blocks that were deemed unfit upon receipt, which seem to have ultimately led to piston wall failure in some engines, so I would not put it beyond Porsche to take an imperfect engine component and try to make it acceptable for use. Personally, I think their gamble with that part in your engine paid off. The engine went 118,000 miles and the part still hadn't failed, and nobody can prove that it ever would have prematurely failed.

I know you have several strong supporters here and I'm probably going to get railed for this conclusion, but I can only conclude that the diagnosis of the initial problem you were experiencing went way off track due to a small, but relatively insignificant piece of metal, simply because the real source of the problem was not yet identified. Retrospectively, it seems that the first thing they should have done after finding that metal is remove and cut the oil filter and determine if there were really significant metal shavings. Had they found nothing in the oil filter prior to disassembly, do you think your shop still would have disassembled the engine? Probably not. After all, the little metal they did find is not really cause for great alarm yet (at least I don't think so, but maybe there will be other very knowledgeable people that disagree). Once you got to the point of disassembling the engine, and given the high mileage, I agree that it was wise to replace it rather than try to reassemble it with some new components, figure out the real problem, and put it back in service; but you were in that situation in the first place because of a fumbled diagnosis that was not performed by an OPC. The shop kind of derailed any case against Porsche for compensating a required engine replacement. The fact that the part probably shouldn't have been used by Porsche in the first place appears to be a valid complaint with legal justification that Porsche had definitely compromised the engine's original build quality in some way and should be obligated to do *something* about it even though it hadn't yet failed, but it is not directly related to the costs you incurred so it's impossible to determine damages owed to you.

Because there is no strong, direct correlation of a major engine part failure (and more specifically the component that was the source of your investigation) to the need to replace that engine, I don't think Porsche will ever conclude they have a direct responsibility for an offer of partial compensation. They might still do it out of goodwill if you persist and eventually reach the right person, and I wish you luck on that. IMHO, Porsche makes more than enough money on these cars to take care of uncommon situations like this.

I would be interested in hearing from other forum members that believe the shop did have sufficient justification to disassemble the engine (excluding that at the point they did it, they couldn't find any other problems yet - that is clearly not sufficient). I don't think that the small piece of metal was significant enough on its own to initiate a tear-down, and if the real problem was fixed the engine may very well have gone on for many thousands more miles.

I personally believe that these engines should go at least 130k miles before needing any major rebuild or replacement. However, given what I read about the limit of Porsche's goodwill, I only have enough confidence in keeping my 996 until it has almost 80k miles, and should I need that, I will quickly change my avatar in this forum and edit previous posts about my one on-track experience in this car. :rolleyes:

I think we all have a couple of really good lessons learned from John's experience:

1) If the diagnosis is being performed somewhere other than a Porsche service center and it gets to the point where they believe they have to tear down the engine, stop there, and take it to a really good Porsche service department. It may be more costly, but one way or another, you're in for a big one anyway (or you might save a lot of money from a misdiagnosis). If the independent shop never found the problem (or if they think they found the problem but they're not convincing), the dealer will need to reinforce the shop's findings (or lack thereof) before you really owe the shop much of anything anyway.

2) If you keep your Porsche over 80k miles, you do so at your own risk of not having Porsche support/goodwill, and can take that into account when determining the value in buying a high-mileage Porsche or keeping your high-mileage Porsche.

Edited June 24, 2007 by John Jones

[Johnnyceesred]

Gearbox failure and replacement at 125,300 miles!!!!!!

Hi all,

There's not been much to update since my last post save 2 points: -

1. As you can see from the title above, my gearbox failed and was replaced. It developed a severe whining noise at around 2,500-3,000 rpm and this was particularly noticeable when manually changing from 3rd to 2nd gear (it's Tiptronic S). I took it to the local OPC whose technician did a test drive and concluded a new gearbox was required. Had that fitted June 7. Whilst fitting the gearbox they also noticed that the rubber mounting on the front-to-rear prop shaft had split and that the only solution was a new prop shaft (Porsche do not supply the rubber mounting separately). So that was fitted June 16. End user cost for these parts and labour would have been around £9,300. The good news is I took out a year's extended warranty on 1st May at around 124,300 miles so all costs were covered by the warranty. That was £895 well spent.

2. I've got the local Trading Standards Office (part of the UK Government's Office of Fair Trading Department) communicating with the OPC that sold me the car and Porsche Cars GB, to see if they can progress my claim for compensation against the cost of the replacement engine etc. I'll update the thread with any news that I can publish.

Regards

John

John,

This has been a fascinating thread. I am really sorry to hear about your problems and I hope that I never have to go through the same thing. First, I'll get straight to the point, then I'll explain. Based on the information we have (and I'm kind of making a big assumption that I have all of the key, relevant information that the shop had when they decided to disassemble it) I believe you have a stronger case against the shop that performed the initial diagnosis than you do against Porsche. I believe that the engine disassembly was premature and was not the appropriate course of action given the evidence. I don't think they did enough to determine that the disassembly was necessary before diving in. I think that they only did it because they couldn't find the source of the problem and had nothing else to follow up on besides a small piece of metal. It was the right decision to eventually replace it *after* it was already disassembled and *potential* trouble parts were identified, but it never needed to get that far in the first place. That probably wouldn't have been necessary for at least another 10k-30k miles.

To try to briefly summarize all that has already been reported with respect to the sequence of events that led to the engine replacement:

1) Engine is running rough. Problem comes and goes, and shifts from one side to another. Several attempts to troubleshoot it don't lead to a solution, but a small piece of metal is found in the case.

2) Engine is disassembled as a result of finding the metal to see if that is the source of the problem. There are definitely a few areas of concern with regard to structural integrity, but catastrophic mechanical failure has not occurred as a result of those issues, and there were no huge metal particle problems (the contents of the oil filter is the biggest factor to me).

3) Ultimately, the source of the misfiring is never determined, but because of the concerns with the structural integrity and its high mileage, the engine is deemed not worth all the trouble to reassemble and restart the troubleshooting process, so the engine is replaced.

Here is the predicament:

1) The engine did not actually experience catastrophic failure. It had a fairly uncommon problem, but it was not self-destructing.

2) The structural issues that were identified do not lend to an explanation of the engine woes. I can't even justify a very loose correlation.

3) The source of the problem that contributed to the engine woes was never identified.

4) The engine was replaced without having experienced a catastrophic failure or identifying the source of the problem that put it in the shop in the first place.

Given all of this, it will not be possible to prove that the structural problem that is the focus of the metallurgical examination would have been the source of the engine's ultimate demise. Who's to say that something else wouldn't have eventually given way first - a crank bearing, a piston, valve springs - all parts that are more likely to fail and not as likely to suggest that Porsche should be responsible for replacing the engine (or at least a partial offer).

I'll bet that Porsche has performed numerous FMEA's (Failure Mode and Effect Analysis) on the failed engines that they've taken back. Since Porsche does not release statistics or other detailed information about engine failures, we will never know if any of those FMEA's pointed to the same part that is the focus of your investigation (though I would like to hear from any mechanics of Porsche's water-cooled engines that have identified this as the source of failure in an engine they removed). If by some chance they had seen that in another engine, the best conclusion they can draw is that this part has some probability of being the ultimate cause of failure, but that it hasn't failed yet and there's no way to prove that something else wouldn't have gone first.

You have many valid points in your case. The piece in question probably never should have been used. I've read about another process Porsche implemented to retrofit new sleeves into new blocks that were deemed unfit upon receipt, which seem to have ultimately led to piston wall failure in some engines, so I would not put it beyond Porsche to take an imperfect engine component and try to make it acceptable for use. Personally, I think their gamble with that part in your engine paid off. The engine went 118,000 miles and the part still hadn't failed, and nobody can prove that it ever would have prematurely failed.

I know you have several strong supporters here and I'm probably going to get railed for this conclusion, but I can only conclude that the diagnosis of the initial problem you were experiencing went way off track due to a small, but relatively insignificant piece of metal, simply because the real source of the problem was not yet identified. Retrospectively, it seems that the first thing they should have done after finding that metal is remove and cut the oil filter and determine if there were really significant metal shavings. Had they found nothing in the oil filter prior to disassembly, do you think your shop still would have disassembled the engine? Probably not. After all, the little metal they did find is not really cause for great alarm yet (at least I don't think so, but maybe there will be other very knowledgeable people that disagree). Once you got to the point of disassembling the engine, and given the high mileage, I agree that it was wise to replace it rather than try to reassemble it with some new components, figure out the real problem, and put it back in service; but you were in that situation in the first place because of a fumbled diagnosis that was not performed by an OPC. The shop kind of derailed any case against Porsche for compensating a required engine replacement. The fact that the part probably shouldn't have been used by Porsche in the first place appears to be a valid complaint with legal justification that Porsche had definitely compromised the engine's original build quality in some way and should be obligated to do *something* about it even though it hadn't yet failed, but it is not directly related to the costs you incurred so it's impossible to determine damages owed to you.

Because there is no strong, direct correlation of a major engine part failure (and more specifically the component that was the source of your investigation) to the need to replace that engine, I don't think Porsche will ever conclude they have a direct responsibility for an offer of partial compensation. They might still do it out of goodwill if you persist and eventually reach the right person, and I wish you luck on that. IMHO, Porsche makes more than enough money on these cars to take care of uncommon situations like this.

I would be interested in hearing from other forum members that believe the shop did have sufficient justification to disassemble the engine (excluding that at the point they did it, they couldn't find any other problems yet - that is clearly not sufficient). I don't think that the small piece of metal was significant enough on its own to initiate a tear-down, and if the real problem was fixed the engine may very well have gone on for many thousands more miles.

I personally believe that these engines should go at least 130k miles before needing any major rebuild or replacement. However, given what I read about the limit of Porsche's goodwill, I only have enough confidence in keeping my 996 until it has almost 80k miles, and should I need that, I will quickly change my avatar in this forum and edit previous posts about my one on-track experience in this car. :rolleyes:

I think we all have a couple of really good lessons learned from John's experience:

1) If the diagnosis is being performed somewhere other than a Porsche service center and it gets to the point where they believe they have to tear down the engine, stop there, and take it to a really good Porsche service department. It may be more costly, but one way or another, you're in for a big one anyway (or you might save a lot of money from a misdiagnosis). If the independent shop never found the problem (or if they think they found the problem but they're not convincing), the dealer will need to reinforce the shop's findings (or lack thereof) before you really owe the shop much of anything anyway.

2) If you keep your Porsche over 80k miles, you do so at your own risk of not having Porsche support/goodwill, and can take that into account when determining the value in buying a high-mileage Porsche or keeping your high-mileage Porsche.

Hi John,

Thankyou so much for a very detailed and reasoned response. It's great to get another person's analysis of the series of events.

I haven't re-read my whole thread so in case I've missed any important detail I'd like to clarify the points below.

I did actually take my car to two different OPC's for diagnosis and got 2 different results and the second one, which is where I bought the car from originally, concluded that the problem "might" be a broken valve spring and to determine that would necessitate them taking out the engine and stripping off the cylinder heads at a cost to me of £2,100 + tax just to prove or disprove their theory, without any guarantee of a correct diagnosis. The advice from the independent, who by the way has many years' experience building, running and maintaining Porsche 917's etc., see his web site http://www.davegriffithsracing.co.uk/aboutus.htm was that if it was a broken valve spring it would be a more consistent problem.

Dave carried out all the tests that an OPC would carry out (leakdown tests, MAF tests etc.) and I'm confident that the tear down was very much a last resort, given that all his contacts (some with Porsche factory training) with their many years' of experience of Porsche engines as well, could offer no explanations either. He also has a very good relationship with the OPC where I bought the car from and he talked to them very openly about the situation and explained everything that he had done and thought about.

If I had stayed with the OPC that did the second diagnosis, the final bill for labour alone could have been in excess of £6,700 + tax and the new engine was £7,356 + tax which make a total of £14,056 + tax, about £3,000 + tax more than I have paid using the independent.

There is a clause in the Sale of Goods Act 1979 in English Law, that states that goods must be "safe and durable" to be fit for purpose. My argument is that the crank cradle did not meet the durability aspect of this law and as it was cracked and flaking was becoming unsafe.

In conclusion, I'm more than confident that the independent took the right course of action and I will pursue the matter to it's final conclusion.

As you can see from the previous update the gearbox and prop shaft have been replaced under extended warranty at 125,300 miles.

Best regards

John