km..or miles??...I cant see how this can work really. You need to carry out a census over a percentage of the total units in service. You also need to factor in..age..history..milage..owners..type of use...engine type...etc etc. Even having 50 or 100 comments it will not show a true measure of the facts. Sorry!

You have proven the value of the statistics - well done.

As I mentioned on a different posting about 996 engine reliability (I think) the position of the crankshaft relative to the hole that supports the seal is not guaranteed as it is not machined at the same time.

It is clear to us that some seals fail at very low mileages - then continue to fail again and again whereas some seals last up to 100K and never fail.

Although it need special tools and even a vernier or micrometer to check that the seal is in square to the crankshaft (as any tool that pushes the seal in does not neccessarily result in a square position because the rubber that it is made of compresses and so even if it is pushed in with a square tool it can end up out of square and needs checking) - there is nothing anyone can do to correct an out of alignment of the seal position right from the manufacturing and assembly stage.

We have measured around 0.25mm out of alignment (some more - some less) and in my view this is a design/manufacturing tolerance that is unreasonable and wrong - although I would have thought a seal design could be developed that could cope with it. For example a seperate seal carrier that can be located in line and then secured in position or an extension of the original casting that holds the main bearings so it also holds the RMS instead of it being held in a seperate casting that is out of line.

The size of the crank journal and the design and quality of the seal will be the same - so it must be that those that fail the most are simply those that go together with the most out of alignment.

There is also some age related stress relieving of the casing that holds the seal because it is not restrained anywhere near the centre being more like a bell housing - which also contributes to the out of alignment.

In my view this should be an accepted fault always repaired FOC by Porsche and I cannot believe that they have not thought out how to fix it by now.

For example - if the crank carrier was extended and a stub protruded into the cylinder casting holding the seal in the crank carrier and with an o ring between that and the cylinder casting - it would be perfectly OK.

Having made that point - most old Porsche's leak a little oil and you know it is not a serious problem - putting a small amount of top up oil in the engine every few weeks will not affect the reliability of anything else and a small tray left strategically on the garage floor can prevent oil staining.

This and the bearing problem in the intermediate shaft, should have been sorted out years ago.

Baz

2002 996. 48000 miles. 1 x RMS to my knowledge.

Hi Dunit,

Thanks again for a most informative post!

Your point about Warranty Direct provokes many thoughts, and the implications are not very encouraging.

For those still knocking the value of this thread, please note that only a very tiny proportion of unhappy customers bother to complain in writing. On that basis, negative postings here about reliability are still only a very small proportion of the reality. So if anyone still wants to, may I respectfully suggest that instead of knocking this thread, you go and ask Warranty Direct or Porsche for facts. Armed with said facts, please inform this forum. Until then, please add stats, or leave well alone. Thank you.

I still expect the failure rate to fall, but I am now confident that we're looking at double figures in percentage terms, and not single figures as I first expected six-nine months ago.

Back to Dunit: Merc took a big hit on warranty claims (and profitability), leading to significant changes for the better. Porsche do not appear to have taken a hit - maybe because so many buyers in Blighty think it is normal to write large cheques to maintain this premium product (annual warranty premiums, or big bills).

The yanks have a four year warranty and they pay less for these cars than we do in the UK! Go figure.......

Just for the record

986 - 10,000 miles - dry as a bone, no problems with the engine, but the roof was another matter 97 my

996 - 19,000 miles 2000MY, not used a drop of oil, not failed, owned for 3 years

2000 C2 3.4

1 x RMS @ 30k miles replaced under warranty
No failures

Currently 68k miles - bought two and half years ago at 29k miles.

Highly unlikely

The incidence of RMS failures recorded is far higher than our customer base or customer records experience - I guess one car in 50 seems to have a problem during a 3 year period but not one in 5 - so I think there must be some element of posting if your car had a fault and perhaps not bothering if it hadn't.

Mind you we always recomend a new seal when doing a clutch etc - so perhaps we intercept more often. (My 0.01% (in a previous posting) was sarcastic but was relating more to very serious engine problems and of course we don't actually know the figures - but Porsche do! - I was just trying to reflect the fact that it is relatively rare).

However with so many having an RMS problem I have revisited the problem and spent longer analysing it and have come up with a new explanation that makes good sense and so we are going to experiment with a new solution and then - after a reasonable period of time - if it works we will inform others.

Baz

98 996 no rms or engine failure issues-66000miles.

996 C2 1999 95,000 miles original engine no RMS in last 3 years but can't answer for before that.

Almost run in now, can't wait to be able to open her up