High Mileage 996 Engines
Discussion
Cheers Baz,
The preventative maintenance idea reminds me of my old E28 M5 that I happened to have when it needed it timing chains replaced etc at 120k. Expensive at the time but good peace of mind.
Also echo question regarding if you have experience of any 997 engine issues and relative strengths.
The preventative maintenance idea reminds me of my old E28 M5 that I happened to have when it needed it timing chains replaced etc at 120k. Expensive at the time but good peace of mind.
Also echo question regarding if you have experience of any 997 engine issues and relative strengths.
Ballcock said:
madala said:
....Baz....that was one helluva interesting read.....thanks....if I lived "oop" North I certainly would be using Hartech to look after my 993.
Happy Christmas.
Try livin in Dublin Happy Christmas.
....Bally I know...and you drink Beamish....living in Dublin!!!!....sheesh....says it all...lol...;)my MK1 Gt3 has 88k miles, put out 361 bhp on a german Maha dyno in May! Doesnt use water, needs a pint of oil after driving to the Ring from Dublin and then 3 hard days lapping at the ring'.....
I change the oil 3-4 times per year in engine and gearbox, OE airfilters and fuel filters.. Recently had the timing chain tensioners changed as a precaution. Mite have chain done soon..
I change the oil 3-4 times per year in engine and gearbox, OE airfilters and fuel filters.. Recently had the timing chain tensioners changed as a precaution. Mite have chain done soon..
noumenon said:
Ballcock said:
madala said:
....Baz....that was one helluva interesting read.....thanks....if I lived "oop" North I certainly would be using Hartech to look after my 993.
Happy Christmas.
Try livin in Dublin Happy Christmas.
Happy Christmas Baz. Makes a change to read a really informative and honest post. Normally posts that refer to the cost cutting exercises of Porsche are met with cries of disbelief. However you have put the point across in such an inoffensive way, no one should get upset. The harsh reality was that Porsche had no option but to reduce build costs in order to survive. In the process they made more money than they had hoped for and hopefully this has stood them in good stead to survive the current global econonic crisis.
Dave 321 said:
my MK1 Gt3 has 88k miles, put out 361 bhp on a german Maha dyno in May! Doesnt use water, needs a pint of oil after driving to the Ring from Dublin and then 3 hard days lapping at the ring'.....
I change the oil 3-4 times per year in engine and gearbox, OE airfilters and fuel filters.. Recently had the timing chain tensioners changed as a precaution. Mite have chain done soon..
Yes but GT3 is 993 based motor unlike the 996I change the oil 3-4 times per year in engine and gearbox, OE airfilters and fuel filters.. Recently had the timing chain tensioners changed as a precaution. Mite have chain done soon..
Baz, thanks for the informative and thought-provoking read.
I know from reading your buyers' guide that you don't do much work on the 928, but do you have any general thoughts on the 928 engine, as I have read in various places that the engines are absolutely bulletproof and can go for enormous mileages without requiring the endless rebuilds that aircooled 911 engines seem to need.
My own experience has been with three examples, a 4.5, a 4.7 and a 32v 5.0 S4, all with mileages well over 100k and none of them consuming oil or behaving other than as they left the factory. All though had regular fluid changes and t-belt / waterpump maintenance.
Cheers
Joel
I know from reading your buyers' guide that you don't do much work on the 928, but do you have any general thoughts on the 928 engine, as I have read in various places that the engines are absolutely bulletproof and can go for enormous mileages without requiring the endless rebuilds that aircooled 911 engines seem to need.
My own experience has been with three examples, a 4.5, a 4.7 and a 32v 5.0 S4, all with mileages well over 100k and none of them consuming oil or behaving other than as they left the factory. All though had regular fluid changes and t-belt / waterpump maintenance.
Cheers
Joel
Just a few follow ups.
Unfortunately I am not privy to what goes on inside the Porsche design department - so it is difficult to state what things may still be weak in the newer engines until they start to fail and come in for rebuild (as the first 996's and Boxsters seemed OK initially). It is only then or by picking up reports of failures on the Internet that I can start to analyse the problem and find explanations and hopefully solutions.
However - at this stage - I don't expect much difference from the 997 although Porsche may have improved the composition of the Lokasil preform (to make it stronger or more stable), and the improved IMS bearing may last longer. The newer RMS is different and allows for some of the missalignment of the crankshaft and the RMS locating hole - but then (inexplicably) during the re-design they decided to do without a spring to hold the seal lip tight to the crankshaft when I also believe that the oil being thrown at high speed against the crankshaft next to the seal - increases the leak potential and a spring would have helped resist that and I don't know why it has not been included.
I am too busy with problems that need solving day to day to worry in advance too much about new ideas and designs. So I don't look into the design of new engines much until they start to come in broken and I have something physical to look at and ponder over. However an intermediate shaft is not in itself a design problem (all the old 911's had one after all) and without it the sprocket diameters should be increased and if they have not been, this in itself could present long term problems. The Intermediate shaft allows for a more gradual speed reduction but if the oil pump is driven from it (as it is on the 911 and 996) it tends to run with low oil pressure just at tickover (as the speed then is a bit low and needs high quality shells and cranks to last) but apart from that it is not usually a problem. Due to the pulsating loads that result from cams operating - it seems that plain bearings (older 911 design and the OK end of the Boxster/996 shaft) are better than ball bearings on the failing end (or at least don't usually fail so badly just fatigue over time).
There is IMHO a little too much pressure applied to the timing chains that wears them against the very long slippers - but this is more to do with keeping them in contact with small sprockets (due to the reduction in diamter of the sprockets to reduce engine dimensions) than the materials. When they do break they just pull out a piece of the link as if that particular link was weak - or they last for ever (if all the links are OK as they usually are). As all older engines will have bores going oval (therefore cracking or increasing blow by) and since crankshaft shells are thinner than I would have liked to see them - by the time most chains are getting tired there are other more important things that should be addressed that are more likely to result in an engine failure. This is why I propose that it will become worthwhile (or perhaps I should say that the public/owners will eventually realise that) for the low cost of the cars and the fantastic performance and comfort - an engine rebuild to fix these problems before a failure occurs - at perhaps around 100 to 140K - will (or should) become the norm and an acceptable cost - OR the additional cost of a waranty/Maintenance Plan (to reduce costs if and when a failure occurs) should become part of the equation when considering ownership.
This is one reason why our Lifetime Maintenance Plan is such good value particularly for these cars because not only would it only cost the parts cost for fixing a failure - but we are happy to include the other modifications and replacements to re-condition the whole engine (regardless of what actually failed) without charge (except for parts and any additional labour directly incurred), resulting in a fuly reconditioned engine at very low cost with all our preventative additions - that are not available elsewhere.
The 928 is a strange animal. It is under stressed and as most are automatic and very powerful - they spend most of their lives running at low revs and modest acceleration and as a result are reliable for a long time.
However several things will eventually catch up with them and then they will prove very expensive to renovate/repair.
The 4 valve heads run with softer cams than the 944 S2 and at lower average revs so the small camshaft chain, sprockets and cams themselves - lasts longer - but will probably let go one day after huge mileage.
The head gaskets are the same as the 944 S2 and will soon start needing replacement through old age rotting them away and then will cost double the 944 cost.
Rubber seals and pipes in the inlets system will eventually fail and be expensive to repair.
Finally there are enough computers etc in that car to get to the moon and back but eventually they will fail through old age and copper wire or silver/solder joints will deteriorate through corrosion and when that happens it will prove almost impossible to justify the repair costs.
They have been good cars up until now (if you like the sheer weight to drive and dated interior) but I expect them to start being too expensive to own soon for most people (but may last longer before that expensive times starts in drier climates than ours).
Finally can I reinforce my opinion that the 996 desrves less criticism and more serious acceptance right now - as it represents by far the best value for money buy of any Porsche I have previously been involved with. Manual or tiptronic are superb to drive, relatively inexpensive to run, extremely reliable and IF (don't forget this next bit when those that prefer something else start dissagreeing) - IF you can afford some kind of protection against the full cost of a very rare engine failure - are low risk buys. You know they are getting so cheap - even if you take the risk of an engine failure (i.e. no cover) compared to what you might have expected to pay a few years ago for anything remotely comparable - they still can be viable.
Perhaps the only people who should think hard before buying one are those that spend all their money buying it and cannot afford any extra to cover a costly failure if it occurs - but then this is advice we give to ALL Porsche buyers anyway! (but as a result of human nature is usually ignored)
Baz
Unfortunately I am not privy to what goes on inside the Porsche design department - so it is difficult to state what things may still be weak in the newer engines until they start to fail and come in for rebuild (as the first 996's and Boxsters seemed OK initially). It is only then or by picking up reports of failures on the Internet that I can start to analyse the problem and find explanations and hopefully solutions.
However - at this stage - I don't expect much difference from the 997 although Porsche may have improved the composition of the Lokasil preform (to make it stronger or more stable), and the improved IMS bearing may last longer. The newer RMS is different and allows for some of the missalignment of the crankshaft and the RMS locating hole - but then (inexplicably) during the re-design they decided to do without a spring to hold the seal lip tight to the crankshaft when I also believe that the oil being thrown at high speed against the crankshaft next to the seal - increases the leak potential and a spring would have helped resist that and I don't know why it has not been included.
I am too busy with problems that need solving day to day to worry in advance too much about new ideas and designs. So I don't look into the design of new engines much until they start to come in broken and I have something physical to look at and ponder over. However an intermediate shaft is not in itself a design problem (all the old 911's had one after all) and without it the sprocket diameters should be increased and if they have not been, this in itself could present long term problems. The Intermediate shaft allows for a more gradual speed reduction but if the oil pump is driven from it (as it is on the 911 and 996) it tends to run with low oil pressure just at tickover (as the speed then is a bit low and needs high quality shells and cranks to last) but apart from that it is not usually a problem. Due to the pulsating loads that result from cams operating - it seems that plain bearings (older 911 design and the OK end of the Boxster/996 shaft) are better than ball bearings on the failing end (or at least don't usually fail so badly just fatigue over time).
There is IMHO a little too much pressure applied to the timing chains that wears them against the very long slippers - but this is more to do with keeping them in contact with small sprockets (due to the reduction in diamter of the sprockets to reduce engine dimensions) than the materials. When they do break they just pull out a piece of the link as if that particular link was weak - or they last for ever (if all the links are OK as they usually are). As all older engines will have bores going oval (therefore cracking or increasing blow by) and since crankshaft shells are thinner than I would have liked to see them - by the time most chains are getting tired there are other more important things that should be addressed that are more likely to result in an engine failure. This is why I propose that it will become worthwhile (or perhaps I should say that the public/owners will eventually realise that) for the low cost of the cars and the fantastic performance and comfort - an engine rebuild to fix these problems before a failure occurs - at perhaps around 100 to 140K - will (or should) become the norm and an acceptable cost - OR the additional cost of a waranty/Maintenance Plan (to reduce costs if and when a failure occurs) should become part of the equation when considering ownership.
This is one reason why our Lifetime Maintenance Plan is such good value particularly for these cars because not only would it only cost the parts cost for fixing a failure - but we are happy to include the other modifications and replacements to re-condition the whole engine (regardless of what actually failed) without charge (except for parts and any additional labour directly incurred), resulting in a fuly reconditioned engine at very low cost with all our preventative additions - that are not available elsewhere.
The 928 is a strange animal. It is under stressed and as most are automatic and very powerful - they spend most of their lives running at low revs and modest acceleration and as a result are reliable for a long time.
However several things will eventually catch up with them and then they will prove very expensive to renovate/repair.
The 4 valve heads run with softer cams than the 944 S2 and at lower average revs so the small camshaft chain, sprockets and cams themselves - lasts longer - but will probably let go one day after huge mileage.
The head gaskets are the same as the 944 S2 and will soon start needing replacement through old age rotting them away and then will cost double the 944 cost.
Rubber seals and pipes in the inlets system will eventually fail and be expensive to repair.
Finally there are enough computers etc in that car to get to the moon and back but eventually they will fail through old age and copper wire or silver/solder joints will deteriorate through corrosion and when that happens it will prove almost impossible to justify the repair costs.
They have been good cars up until now (if you like the sheer weight to drive and dated interior) but I expect them to start being too expensive to own soon for most people (but may last longer before that expensive times starts in drier climates than ours).
Finally can I reinforce my opinion that the 996 desrves less criticism and more serious acceptance right now - as it represents by far the best value for money buy of any Porsche I have previously been involved with. Manual or tiptronic are superb to drive, relatively inexpensive to run, extremely reliable and IF (don't forget this next bit when those that prefer something else start dissagreeing) - IF you can afford some kind of protection against the full cost of a very rare engine failure - are low risk buys. You know they are getting so cheap - even if you take the risk of an engine failure (i.e. no cover) compared to what you might have expected to pay a few years ago for anything remotely comparable - they still can be viable.
Perhaps the only people who should think hard before buying one are those that spend all their money buying it and cannot afford any extra to cover a costly failure if it occurs - but then this is advice we give to ALL Porsche buyers anyway! (but as a result of human nature is usually ignored)
Baz
Ballcock said:
noumenon said:
Ballcock said:
madala said:
....Baz....that was one helluva interesting read.....thanks....if I lived "oop" North I certainly would be using Hartech to look after my 993.
Happy Christmas.
Try livin in Dublin Happy Christmas.
One of the most frigtening drives ever. Much scarier than my first lap of the ring or first lap of the arc de triomphe.
hartech said:
You know they are getting so cheap - even if you take the risk of an engine failure (i.e. no cover) compared to what you might have expected to pay a few years ago for anything remotely comparable - they still can be viable.
Baz
Actually, that is a really good point... You can buy a 996 AND a brand spanking new engine for the same price as a similar mileage 993 in some cases: and have a newer, faster car, with a more modern interior, etc...Baz
Have to make a decision what to do with my 996 next month (balloon finance payment due)... I figured it will cost me more to change into a 997 (which I'm not too sure about tbh) than keep mine and buy a new engine if needed. So I will probably refinance the balloon and keep the car and just be prepared to splash out on a new / recon motor if it all goes tits up at some stage!
I'll keep you posted on how high mileage you can get out of a 3.4 original engine... 107k so far and counting
I'll keep you posted on how high mileage you can get out of a 3.4 original engine... 107k so far and counting
Mine has done 96,000 miles now but had a brand new engine fitted in 2005 by Porsche Reading so has only done 42,000 on new engine and is as sweet as a nut. Does anyone know if they changed anything , would a 2005 engine be identical to a 2000 engine or would there have been a few minor changes ?
Edited by woogie on Tuesday 23 December 10:39
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