996-997 wet-sump engine reliability: enter your stats here!
Discussion
Thanks for your insight sterling ... On first glance , you seem to have a good business set up there , very transparent , congrats!!
Would you hear back from buyers of your cars , if they've had a blown engine? ..
I'd imagine some would ring you if only for advice on the warranty claim...
Would you hear back from buyers of your cars , if they've had a blown engine? ..
I'd imagine some would ring you if only for advice on the warranty claim...
So given the stats thrown up here , you should be getting phone calls at a rate of about one every 2 months!!
Somehow I doubt you are... Makes me even more convinced that the engine failure rate is much lower than the statistics on this thread.
However ,that doesn't mean I wouldn't get an OPC warranty!!
Somehow I doubt you are... Makes me even more convinced that the engine failure rate is much lower than the statistics on this thread.
However ,that doesn't mean I wouldn't get an OPC warranty!!
Ballcock said:
So given the stats thrown up here , you should be getting phone calls at a rate of about one every 2 months!!
Somehow I doubt you are... Makes me even more convinced that the engine failure rate is much lower than the statistics on this thread.
However ,that doesn't mean I wouldn't get an OPC warranty!!
My TVR doesn't leak anywhere near as much as my 996 did Somehow I doubt you are... Makes me even more convinced that the engine failure rate is much lower than the statistics on this thread.
However ,that doesn't mean I wouldn't get an OPC warranty!!
HTH :-|
Back from one beach/mountainous landscapes holiday, and a fine time was had by all! 
Interesting posts in the meantime. Here goes....
I still think they are great cars to look at and enjoy. BUT......
1. Accept his higher RMS rate, as closer to the truth (use his sample size of 50 cars/year, go back however many years you like);
2. Add his higher RMS rates - weighted appropriately, of course - to this thread's statistics;
3. and reduce the blown engine rate - weighted again - according to his postings?
Just curious.
Whatever you choose to do, the maths suggest the rates will still be higher than expected (see Dunit's postings - he is, after all, an expert too. Or should we discard his contributions?).
Meanwhile, this is more like it as far as the ownership aspiration should be (again in my books) and I wish there were more of this type of posting:
Interesting posts in the meantime. Here goes....Ballcock said:
So given the stats thrown up here , you should be getting phone calls at a rate of about one every 2 months!!
Why? If you have an OPC warranty, why call the supplying Indie dealer to rectify a major, or any known problem covered by the OPC warranty? No need...Ballcock said:
Somehow I doubt you are... Makes me even more convinced that the engine failure rate is much lower than the statistics on this thread.
Possibly and even probably so. However, even if the rate were halved, or reduced to 25% of that proposed by this thread (check out Option 1 at the end of this post), should that be considered okay for a premium product?Ballcock said:
However ,that doesn't mean I wouldn't get an OPC warranty!!
Precisely - after all, if it were a 1% failure rate, I doubt you'd need the warranty! The warranty makes good financial sense because of the probability and consequence issues (risk = probability x consequence. All the warranty threads on here give a good indication of the risk rating, methinks).I still think they are great cars to look at and enjoy. BUT......
Stirling said:
My own experience is that 60% of the cars i buy need the RMS changing, Ok I'm not one of the larger volume specialists i sell 40/50 cars a year
That's a much higher rate than this thread has suggested. So, Ballcock, will you:1. Accept his higher RMS rate, as closer to the truth (use his sample size of 50 cars/year, go back however many years you like);
2. Add his higher RMS rates - weighted appropriately, of course - to this thread's statistics;
3. and reduce the blown engine rate - weighted again - according to his postings?
Just curious.
Whatever you choose to do, the maths suggest the rates will still be higher than expected (see Dunit's postings - he is, after all, an expert too. Or should we discard his contributions?).
Meanwhile, this is more like it as far as the ownership aspiration should be (again in my books) and I wish there were more of this type of posting:
Rappa said:
1999 3.4. I have all the history. No Engine Failures, Clutch replaced at 69585 miles and RMS done as a precautionary measure.
Car fine only other faults have been: Aircon Rads 82000 miles.
Alternator 54000 miles.
Cab hood mechanism 71000 miles.
Sorry for the long post. Happily, I'll be silent for a few more days (off tomorrow for the rest of my hols) Car fine only other faults have been: Aircon Rads 82000 miles.
Alternator 54000 miles.
Cab hood mechanism 71000 miles.
One point re rms that I have never seen discussed is with 993's
i did the rms on 3 993's last year all with sub 50,000 mileages
but then again these were 10 year old cars
Although before we go too deep down that route, it does seem to be widely acknowledged that the RMS problem is down to poor casting at the factory
i did the rms on 3 993's last year all with sub 50,000 mileages
but then again these were 10 year old cars
Although before we go too deep down that route, it does seem to be widely acknowledged that the RMS problem is down to poor casting at the factory
I think there are 4 contributary causes of the RMS problem.
(1) Because of the design of the crankcase - unlike most cars and other Porsche engines - the hole that the seal fits in is not machined at the same time as the crankshaft bores nor in the same casting and some misalignment occurs - worse in some than others. Sress relieving of the casing may also contribute to this out of alignment.
(2) There is no machined flat face to check/measure against in the casing to ensure the seal is in square (although it can be done from the crankshaft end).
(3) The tool used to knock the seal in square - doesn't - because the rubber that the seal is made of can compress and so even if the tool is square - the seal usually is not after it is knocked in unless it is measured afterwards and then knocked in square piecemeal and checked.
I think the provision of a tool may make some people assume that it will be automatically knocked in square - which it isn't - so some may not check afterwards.
Porsche redesigned the seal to be made in a kind on "memory plastic" for the 997 so that it will gradually conform to any out of alignment and also made the hole in the centre resist stretching - so it enables the out of alignment to be pulled into position - although strangely they decicded to do without a spring on the inside (as most seals have a spring). I think these changes reflect their belief that it was the out of alignment that was the cause (which I too initially put the problem down to).
However - unfortunately I now think the primary cause is something different.
(4) Most rear crankshafts have nothing else nearby except the crankshaft and so the centrifugal force of the rotating crankshaft throws off oil and applies little pressure to the seal area where it touches the crankshaft - so it doesn't have too big a job to do.
Although other cars and 911's have chains driving the camshafts these are usually at the front and there is usually a shell bearing between the chains and the front seal so that seal is protected from the forces of oil being thrown about by the chains.
This engine has 2 chains right next to the RMS - one driving the intermediate shaft and one driving one bank of cylinders camshafts. These chains are travelling in an oil bath at very high speed (something like 50mph @ 6500 rpm). The design of a chain makes it like a pump at this speed and it will be throwing oil with huge force and velocity at everything in sight and in turn against the crankshaft where the seal sits against the crankshaft journal. It if just like holding a pipe discharging a high pressurised feed of large quantities of oil directly against the seal face.
This is a relatively new problem and I think requires a kind of baffle or fixed or rotating disc to keep the majority of that pressurised full force oil flow away from the area of the crankshaft seal.
We have developed our own solution but if others think this explanation is right - then no doubt they too will find a simple way to improve the outcome - it's just a pity Porsche don't seem to have solved it completely yet. There again I too may not yet have found the right answer - time will tell!
Having said all that it rarely results in a problem over oil levels and a simple baking tray strategically placed in the garage usually is all that is needed.
Baz
This engine has
(1) Because of the design of the crankcase - unlike most cars and other Porsche engines - the hole that the seal fits in is not machined at the same time as the crankshaft bores nor in the same casting and some misalignment occurs - worse in some than others. Sress relieving of the casing may also contribute to this out of alignment.
(2) There is no machined flat face to check/measure against in the casing to ensure the seal is in square (although it can be done from the crankshaft end).
(3) The tool used to knock the seal in square - doesn't - because the rubber that the seal is made of can compress and so even if the tool is square - the seal usually is not after it is knocked in unless it is measured afterwards and then knocked in square piecemeal and checked.
I think the provision of a tool may make some people assume that it will be automatically knocked in square - which it isn't - so some may not check afterwards.
Porsche redesigned the seal to be made in a kind on "memory plastic" for the 997 so that it will gradually conform to any out of alignment and also made the hole in the centre resist stretching - so it enables the out of alignment to be pulled into position - although strangely they decicded to do without a spring on the inside (as most seals have a spring). I think these changes reflect their belief that it was the out of alignment that was the cause (which I too initially put the problem down to).
However - unfortunately I now think the primary cause is something different.
(4) Most rear crankshafts have nothing else nearby except the crankshaft and so the centrifugal force of the rotating crankshaft throws off oil and applies little pressure to the seal area where it touches the crankshaft - so it doesn't have too big a job to do.
Although other cars and 911's have chains driving the camshafts these are usually at the front and there is usually a shell bearing between the chains and the front seal so that seal is protected from the forces of oil being thrown about by the chains.
This engine has 2 chains right next to the RMS - one driving the intermediate shaft and one driving one bank of cylinders camshafts. These chains are travelling in an oil bath at very high speed (something like 50mph @ 6500 rpm). The design of a chain makes it like a pump at this speed and it will be throwing oil with huge force and velocity at everything in sight and in turn against the crankshaft where the seal sits against the crankshaft journal. It if just like holding a pipe discharging a high pressurised feed of large quantities of oil directly against the seal face.
This is a relatively new problem and I think requires a kind of baffle or fixed or rotating disc to keep the majority of that pressurised full force oil flow away from the area of the crankshaft seal.
We have developed our own solution but if others think this explanation is right - then no doubt they too will find a simple way to improve the outcome - it's just a pity Porsche don't seem to have solved it completely yet. There again I too may not yet have found the right answer - time will tell!
Having said all that it rarely results in a problem over oil levels and a simple baking tray strategically placed in the garage usually is all that is needed.
Baz
This engine has
hartech said:
(1) unlike most cars and other Porsche engines - the hole that the seal fits in is not machined at the same time as the crankshaft bores nor in the same casting and some misalignment occurs
Now I know RMS is nowhere as serious a problem as an engine failure, but still, why should the cars have this problem for so long. Is it possible that it is, for Porsche, a by-product of performance cars, and that maybe they have a strenious bureaucractic procedure, workflows, many departments, teams and checklists envolved to perform the needed enhancement or fix, and they just couldn't bother, since they are focusing on other things (like painting Caymans black with stripes...)Kay
Very often designers accept some things as std and not needing any particular thought - like an RMS perhaps until there is a problem - when they have to think out what the problem is before coming up with a solution.
Different people have different ideas - some are right - some are wrong and some are in between - but often the actual main problem is not diagnosed first time. So when the RMS had a problem it would not be unusual to think - what is different about this RMS and realising that it is often a little off centre and attribute that as the reason.
Then you design a solution that improves the quality of the seal itself - but find it only partly works - so there must be another contributory factor.
All this takes time as does providing a manufactured answer to supply to dealers.
Politics often comes into this as people naturally defend their initial designs etc and therefore try and find fault somwehere else (like with the seal manufacturer or assemblers etc).
In this case I think it is possible that the out of alignment was a problem that provided a false solution - i.e. it was whoever designed the crankcase - not the seal (if you see what I mean) and so it has delayed finding the right cause. The desire to make cylinder heads common resulted in the rear camshaft chain and its proximity to the RMS - so it could even be blamed on that decision.
Ultimately someone has to think out the right cause and often it is someone not employed inside Porsche (and therefore not subject of politics or career issues). Or Porsche designers may know the answer and have decided they don't want to change it until the next model upgrade (if at all).
Although there are those who contribute to this forum who imagine that designers inside Porsche have some superhuman quality that ordinary people like me don't posses - they should realise that if fate had resulted in me (or countelss other degree qualified mechanical engineers) being born in Germany - we too may have ended up working in the Porsche design team and therefore there is nothing unusual at all in a solution being found first outside of the Porsche factory. Good experienced designers always know this and often don't mind discussing such issues with anyone with something useful to offer - although there is supposed to be a cultural difference in Teutonic thinking that may make them less comfortable discussing failings - I don't really know how true that tradition is!
There is nothing more humbling than trying to solve engineering problems and so good designers always accept their own shortcomings and are prepared to look for new answers whereas managers, PR departments, accountants, etc usually don't and from, this politics emerges.
It would not suprise me at all if my suggestion is entirely wrong but at the moment - it is the one I think is most likely and only time will prove that theory right or wrong.
Baz
Different people have different ideas - some are right - some are wrong and some are in between - but often the actual main problem is not diagnosed first time. So when the RMS had a problem it would not be unusual to think - what is different about this RMS and realising that it is often a little off centre and attribute that as the reason.
Then you design a solution that improves the quality of the seal itself - but find it only partly works - so there must be another contributory factor.
All this takes time as does providing a manufactured answer to supply to dealers.
Politics often comes into this as people naturally defend their initial designs etc and therefore try and find fault somwehere else (like with the seal manufacturer or assemblers etc).
In this case I think it is possible that the out of alignment was a problem that provided a false solution - i.e. it was whoever designed the crankcase - not the seal (if you see what I mean) and so it has delayed finding the right cause. The desire to make cylinder heads common resulted in the rear camshaft chain and its proximity to the RMS - so it could even be blamed on that decision.
Ultimately someone has to think out the right cause and often it is someone not employed inside Porsche (and therefore not subject of politics or career issues). Or Porsche designers may know the answer and have decided they don't want to change it until the next model upgrade (if at all).
Although there are those who contribute to this forum who imagine that designers inside Porsche have some superhuman quality that ordinary people like me don't posses - they should realise that if fate had resulted in me (or countelss other degree qualified mechanical engineers) being born in Germany - we too may have ended up working in the Porsche design team and therefore there is nothing unusual at all in a solution being found first outside of the Porsche factory. Good experienced designers always know this and often don't mind discussing such issues with anyone with something useful to offer - although there is supposed to be a cultural difference in Teutonic thinking that may make them less comfortable discussing failings - I don't really know how true that tradition is!
There is nothing more humbling than trying to solve engineering problems and so good designers always accept their own shortcomings and are prepared to look for new answers whereas managers, PR departments, accountants, etc usually don't and from, this politics emerges.
It would not suprise me at all if my suggestion is entirely wrong but at the moment - it is the one I think is most likely and only time will prove that theory right or wrong.
Baz
bcnrml said:
. So, Ballcock, will you:
1. Accept his higher RMS rate, as closer to the truth (use his sample size of 50 cars/year, go back however many years you like);
2. Add his higher RMS rates - weighted appropriately, of course - to this thread's statistics;
3. and reduce the blown engine rate - weighted again - according to his postings?
Just curious.
Funnily enough I'll accept any rate of RMS failure , having been the 'victim' of such failure in the past , I can confirm it's no biggie.1. Accept his higher RMS rate, as closer to the truth (use his sample size of 50 cars/year, go back however many years you like);
2. Add his higher RMS rates - weighted appropriately, of course - to this thread's statistics;
3. and reduce the blown engine rate - weighted again - according to his postings?
Just curious.
You'll notice none of my postsshow any interest in oil leaks , they're part of our Porsche motoring pleasure , it's a long standing Pork tradition that would be a shame to break at this stage
I do think it would be a mistake to reduce the failure rate on just one dealers experience , but it would be interesting for Baz , Sterling , Henry and RSJ to throw a few words together on this thread and divulge how many engine failures they've had on 996's they've sold in the last year or so...
I'd be very surprised if the rate is any higher than 2-3%
Granted they're going to say that they only choose to sell the best cars , but my answer back is that 996 engine failures don't follow any set pattern , can happen just as quickly to a well serviced , sympathetically run low mileage car just as quickly as an old abused model. In fact this is probably the reason we're so interested in 996 engine failures ... We can't predict which cars will and which cars won't.
So I'm going to stick with my gut feel of between 2-3% , and I'll be well prepared to eat humblest of pie if the stats can prove otherwise..
Btw , 2-3% is still unacceptably high ...
Ok I can only remember ever having had a failed valve spring in a 996/Boxster car we have sold (and as he was on our maintenance plan it only cost him parts to repair).
Similarly I don't remember any car we look after having a failed engine.
We are rebuilding on average 1 or 2/month but I expect that to increase.
Serious weak spots are timing chains, big ends, cracked cylinders, seized cylinders (due to ovality allowing too much piston blow by and overheating and blowing away the oil film), intermediate shaft bearings, variocam solenoids, cracked cylinder heads (usually showing as oil in the coolant). This accounts for failures brought here for repair so far - almost always we have never seen the car before - so it is difficult to attribute the cause just to the design or construction (most cars have some seized exhaust bolts that shear on removal and need helicoiling).
Before big ends fail usually the white metal has rubbed away leaving a trace of copper in the oil and oil filter (but it is a rather thin layer of white metal anyway).
The rest seem random and unpredictable.
We have seen many engines that are running well after covering over 100K and up to 140K.
It seems that if they keep going they are really rather good and yet they can fail anything from about 7K upwards.
We have still always been able to rebuild but it can take some time to process. We also have 10 units we are hoping to rebuild for stock soon (probably have time this Autumn) to speed up turn around times (including all models i.e. 2.5, 2.7, 3.2 and 3.4). We do not yet have a donor 3.6 engine but I guess it will not be very long before we do (anyone out there got one) although we have repaired them.
It is impossible for us to provide statistics except to say that the only failure in cars we sold or look after was one in say 100 ish (1%) and that was the valve spring that has never been repeated - but then we have probably only looked after most of them for about 3-5 years and not throughout their life.
I hope that helps - in time more repairs will result in better statistics - but it is still rare and of course there are not many places rebuilding so those that do get more of the business than say with 944/968's or other 911 variants.
Baz
Similarly I don't remember any car we look after having a failed engine.
We are rebuilding on average 1 or 2/month but I expect that to increase.
Serious weak spots are timing chains, big ends, cracked cylinders, seized cylinders (due to ovality allowing too much piston blow by and overheating and blowing away the oil film), intermediate shaft bearings, variocam solenoids, cracked cylinder heads (usually showing as oil in the coolant). This accounts for failures brought here for repair so far - almost always we have never seen the car before - so it is difficult to attribute the cause just to the design or construction (most cars have some seized exhaust bolts that shear on removal and need helicoiling).
Before big ends fail usually the white metal has rubbed away leaving a trace of copper in the oil and oil filter (but it is a rather thin layer of white metal anyway).
The rest seem random and unpredictable.
We have seen many engines that are running well after covering over 100K and up to 140K.
It seems that if they keep going they are really rather good and yet they can fail anything from about 7K upwards.
We have still always been able to rebuild but it can take some time to process. We also have 10 units we are hoping to rebuild for stock soon (probably have time this Autumn) to speed up turn around times (including all models i.e. 2.5, 2.7, 3.2 and 3.4). We do not yet have a donor 3.6 engine but I guess it will not be very long before we do (anyone out there got one) although we have repaired them.
It is impossible for us to provide statistics except to say that the only failure in cars we sold or look after was one in say 100 ish (1%) and that was the valve spring that has never been repeated - but then we have probably only looked after most of them for about 3-5 years and not throughout their life.
I hope that helps - in time more repairs will result in better statistics - but it is still rare and of course there are not many places rebuilding so those that do get more of the business than say with 944/968's or other 911 variants.
Baz
Thanks for that Baz , that really is all very heartening (Hartening 
) stuff ...
One point you bring up which might be worth discussion is whether we include high mileage 996 failures when referring to 'premature/unpredictable' failures (ie the sort of well documented failures that needed top end rebuilds etc. in previous 911's ).
I think it's fair to assume that these engines will need some work as they reach or exceed 100k miles. This is something that's expected , and gets borne out by the sort of price folk are willing to pay (or not willing to pay as the case may be!) for a high mileage 996.
Failures will increase over time , but it's also reasonable to emphasise that this is the same with any car made ...
Yes folks , even the omnipotent 993 is not impervious to miles on the odo
) stuff ... One point you bring up which might be worth discussion is whether we include high mileage 996 failures when referring to 'premature/unpredictable' failures (ie the sort of well documented failures that needed top end rebuilds etc. in previous 911's ).
I think it's fair to assume that these engines will need some work as they reach or exceed 100k miles. This is something that's expected , and gets borne out by the sort of price folk are willing to pay (or not willing to pay as the case may be!) for a high mileage 996.
Failures will increase over time , but it's also reasonable to emphasise that this is the same with any car made ...
Yes folks , even the omnipotent 993 is not impervious to miles on the odo
Very good point Ballcock, because all Porsches need engine/gearbox attention sometime. It is really a little too early to establish generaL rules for them yet - but I have come up with the following clues as far as I can tell so far.
Early 911's up to say 1994 say 130K is usually top end only - perhaps a full rebuild if a 964. Bottom ends probably around 200K+ very rare at present. 993's last a little longer due partly to the hydraulic tappets and partly due to the head sealing rings making them last longer). Some low mileage 3.2's need a top end after only 70K due to premature piston ring wear.
944's/968's top ends (head gaskets etc) probably nearer 140K typical & perhaps nearer 200K to 240K for bottom ends as well.
996's and Boxsters probably around 120 to 140K - probably missing out on the top end issue and going for the full rebuild all at the same time (top ends seem better than previous models apart from the plastic cam chain runners (similar problem with 944 S, S2 & 968's though) bottom ends seem good as well but not quite as good as previous regarding big end shells I think and no regrind shells available yet).
The fact that the post '96 cars are water cooled does add problems with radiators, water pumps, head gaskets and perished coolant pipes and cracked header tanks - however not more really than most water cooled cars and similar to 944's/968's.
Overall - for a high performance car - one of the best on the market.
For 996's & Boxsters - most rebuilds will cost similar to previous engines - probably around £5K (+Vat) for a whole engine job (although it can cost more if a crankshaft is damaged etc - perhaps more up towards £7K depending upon how far the rebuild goes). The decision about how far to go is important because as Porsche's reach say 15 years old many buyers do very little mileage and own them as a toy/classic rather than a race car or daily transport - the the remaining mileage anticipated may be so low that some parts of a rebuild/renovation may be reasonably delayed a few more years.
Engine failures for lower mileage engines may only cost around £3-4K if other associated parts are still in good condition. To cover all this we have a comprehensive menu containing over 140 options that enable quick pricing to be discussed with customers. We also hope to build up some reconditioned engines this Autumn but then they will have the full monty and be guaranteed and be a little more expensive.
Overall despite the doom and gloom merchants I cannot help looking at an early Boxster or 996 as a hell of a lot of modern sports car for between say £12k and £25K and if only buyers were aware of the comparatively rare possibility of an engine rebuild a little earlier than previous models - or if they are lucky - a similar cost and time frame - then they still seem to me excellent value for money.
It is only those that over extend themselves to buy the most expensive example they can afford and then have a problem that they cannot afford to fix - that should be unhappy - for more well read individuals taking all the possibilities into account - they still seem to me a brilliant buy. They cost similar to much earlier cars amd may last a few more years or if not at least they can be rebuilt - perhaps a little sooner than earlier models but for so much more of a modern, comfortable and fast car - it seems good value to me especially as the rate of depreciation slows down considerably under the £15K level (say).
Baz
Early 911's up to say 1994 say 130K is usually top end only - perhaps a full rebuild if a 964. Bottom ends probably around 200K+ very rare at present. 993's last a little longer due partly to the hydraulic tappets and partly due to the head sealing rings making them last longer). Some low mileage 3.2's need a top end after only 70K due to premature piston ring wear.
944's/968's top ends (head gaskets etc) probably nearer 140K typical & perhaps nearer 200K to 240K for bottom ends as well.
996's and Boxsters probably around 120 to 140K - probably missing out on the top end issue and going for the full rebuild all at the same time (top ends seem better than previous models apart from the plastic cam chain runners (similar problem with 944 S, S2 & 968's though) bottom ends seem good as well but not quite as good as previous regarding big end shells I think and no regrind shells available yet).
The fact that the post '96 cars are water cooled does add problems with radiators, water pumps, head gaskets and perished coolant pipes and cracked header tanks - however not more really than most water cooled cars and similar to 944's/968's.
Overall - for a high performance car - one of the best on the market.
For 996's & Boxsters - most rebuilds will cost similar to previous engines - probably around £5K (+Vat) for a whole engine job (although it can cost more if a crankshaft is damaged etc - perhaps more up towards £7K depending upon how far the rebuild goes). The decision about how far to go is important because as Porsche's reach say 15 years old many buyers do very little mileage and own them as a toy/classic rather than a race car or daily transport - the the remaining mileage anticipated may be so low that some parts of a rebuild/renovation may be reasonably delayed a few more years.
Engine failures for lower mileage engines may only cost around £3-4K if other associated parts are still in good condition. To cover all this we have a comprehensive menu containing over 140 options that enable quick pricing to be discussed with customers. We also hope to build up some reconditioned engines this Autumn but then they will have the full monty and be guaranteed and be a little more expensive.
Overall despite the doom and gloom merchants I cannot help looking at an early Boxster or 996 as a hell of a lot of modern sports car for between say £12k and £25K and if only buyers were aware of the comparatively rare possibility of an engine rebuild a little earlier than previous models - or if they are lucky - a similar cost and time frame - then they still seem to me excellent value for money.
It is only those that over extend themselves to buy the most expensive example they can afford and then have a problem that they cannot afford to fix - that should be unhappy - for more well read individuals taking all the possibilities into account - they still seem to me a brilliant buy. They cost similar to much earlier cars amd may last a few more years or if not at least they can be rebuilt - perhaps a little sooner than earlier models but for so much more of a modern, comfortable and fast car - it seems good value to me especially as the rate of depreciation slows down considerably under the £15K level (say).
Baz
Hartech,
Your theory on the cam chain pumping oil contributing to RMS failure is interesting. I assume this pumping would not occur on dry sumped cars (turbo/GT2/3) - this seems consistent with anecdotal evidence that suggests the problem is much rarer in these engines. The fact that some dry sump cars do occassionally have RMS failures would suggest that the "alignment" failure mode can still apply (which would also make sense as this is presumably a common build feature between dry/wet sump engines). Or do the dry sump cars have better alignment checks etc. during manufacture - perhaps resulting in their supposedly significantly higher cost to make?
Finally, is the "alignment tolerant"/ post May 05 upgraded RMS in the 997 retrofittable to earlier cars as they get their RMSs replaced?
Cheers
Your theory on the cam chain pumping oil contributing to RMS failure is interesting. I assume this pumping would not occur on dry sumped cars (turbo/GT2/3) - this seems consistent with anecdotal evidence that suggests the problem is much rarer in these engines. The fact that some dry sump cars do occassionally have RMS failures would suggest that the "alignment" failure mode can still apply (which would also make sense as this is presumably a common build feature between dry/wet sump engines). Or do the dry sump cars have better alignment checks etc. during manufacture - perhaps resulting in their supposedly significantly higher cost to make?
Finally, is the "alignment tolerant"/ post May 05 upgraded RMS in the 997 retrofittable to earlier cars as they get their RMSs replaced?
Cheers
///ajd said:
Hartech,
Your theory on the cam chain pumping oil contributing to RMS failure is interesting. I assume this pumping would not occur on dry sumped cars (turbo/GT2/3) - this seems consistent with anecdotal evidence that suggests the problem is much rarer in these engines. The fact that some dry sump cars do occassionally have RMS failures would suggest that the "alignment" failure mode can still apply (which would also make sense as this is presumably a common build feature between dry/wet sump engines). Or do the dry sump cars have better alignment checks etc. during manufacture - perhaps resulting in their supposedly significantly higher cost to make?
I think if you read some of Baz's other posts on the subject the usual cause of RMS failure in a dry sumped engine is simply that the seal has worn out - it is only a piece of plastic after all. I believe the dry-sumped engines (all derived from the 964 engine) are built entirely differently from the M96 engines and so the alignment failure does not apply.Your theory on the cam chain pumping oil contributing to RMS failure is interesting. I assume this pumping would not occur on dry sumped cars (turbo/GT2/3) - this seems consistent with anecdotal evidence that suggests the problem is much rarer in these engines. The fact that some dry sump cars do occassionally have RMS failures would suggest that the "alignment" failure mode can still apply (which would also make sense as this is presumably a common build feature between dry/wet sump engines). Or do the dry sump cars have better alignment checks etc. during manufacture - perhaps resulting in their supposedly significantly higher cost to make?
I own a 996 c4, I bought it from a reputal garage but without a Porsche warranty as it was just over 3 years old, within three months of ownership only having done 24K from new it dropped a valve through breaking a spring, I asked Porsche if this was heard of in the " bomb proof 911" and they replied that it had never been heard of before, much to my dismay after paying 41K for the car I now had a bill for 5K to repair it.
I now have a full Porsche warrenty at a cost of £900 a year, since that failure I have only had minor repairs, the car is now 5 years old.
I now have a full Porsche warrenty at a cost of £900 a year, since that failure I have only had minor repairs, the car is now 5 years old.
I'm now on to my third Porsche.
I drive them 20000 miles a year. They are driven almost daily, as everyday drivers, but also sometimes around racetracks on the weekends.
No problems. No RMS. Nothing in around 150000 miles. Last weekend I ran out of petrol because the petrol guage is giving incorrect readings. The first time I've had a problem.
These things have to be driven, and then the seals will be fine. If you sit the car in a garage and only take it out at the weekends you're going to have problems.
Rgds, WalterU
I drive them 20000 miles a year. They are driven almost daily, as everyday drivers, but also sometimes around racetracks on the weekends.
No problems. No RMS. Nothing in around 150000 miles. Last weekend I ran out of petrol because the petrol guage is giving incorrect readings. The first time I've had a problem.
These things have to be driven, and then the seals will be fine. If you sit the car in a garage and only take it out at the weekends you're going to have problems.
Rgds, WalterU
Edited by WalterU on Monday 10th September 22:54
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