996 RMS survey results

[NicD]

Just before I rush off for a week in the sun, we have almost all the 996 survey results input and I thought I would share.

We will chase up those who haven't replied over the next month

Results:
----------
sent 1158
Returned 450
no fault 343
% returned 38.9%
% - RMS failed, of those returned 23.8%


The really interesting (and hopeful) thing is that only a few have had more than one failure and only one has had four - Berny - I thought you had more than this, you should return your form.

1 had 4 RMS failures
1 had 3
6 had 2

The engine failures question is a little confused as while 25 ticked this box, only one gave details. I will follow up on this also.

 

[garyandjanet]

Thank you very much for that.

Facts are always good, allows you to make your own mind up

 

[Guest]

No engine failures then?

 

[Guest]

Are we supposing that the 708 that did not reply had not experienced any problems? If this is so, then we are saying that 107 had an RMS leak, out of those 1158 canvassed, or 9.24 percent. Making this is assumption gives us the best case, as opposed to assuming that our respondents are a representative sample.
Therefore, the chances of having an RMS leak are between 1 in 10 and 1 in 4. You have clearly spotted that I am not statistician, and so I could argue that the likelihood is 1 in 7 (half way between worst and best cases?).

Is this a good thing?

Nic, thanks for the 'heads up', and have an enjoyable break. Now, I wonder what the oil seals are like in a Rolls-Royce gas turbine? Pretty good, I reckon!!!!

 

[Guest]

ORIGINAL: NicD
Berny - I thought you had more than this, you should return your form.

Uh? I sent the form back to you the day I got it. Are you saying you have not got my survey form?

 

[Guest]

Nic,
just to clarify, are you saying you have not got my survey form?

 

[Sundeep]

blimey !

good return though (agreed?) but 24 out of every 100 suffered from the RMS problem...

throw a bit of rounding in.... then 1 in 4 996's will suffer from the dreaded RMS failure..

I realised it was a problem but not that much []

just to check, to aid my knowledge, am I right in assuming the GT3, GT2 & Turbo don't suffer from such a problem (or a much lower %?) due to the exotic engine material used????



regards

 

[Mark_Bennett]

From Nic's 1st post, I think he may be off for a week...

 

[Guest]

am I right in assuming the GT3, GT2 & Turbo don't suffer from such a problem (or a much lower %?) due to the exotic engine material used????

That is the current understanding. GT3/2 and TT aren't so much exotic, as just a different design. Theirs is based upon the long standing race proven design, evolved from 964 (not sure which model) to 993 GT2, to GT1, to 996.
Due to higher stresses, they decided to play it safe.

C2/C4 design was a clean sheet effort. Unfortunately, whilst it looks good on paper, perhaps there is some weakness that was not foreseen. I think that there may be a number of route causes, plus the issue is also being made worse by a design that seems to be marginal.

I think that the main difference is 8 main bearings on the GT3/2 against 7 on the C2, and cast iron bearing holders on the C2 against mounting them directly in the alloy (to reduce the differential thermal expansion, so C2 design should be better).
However, I have not seen any diagrams/taken one apart, so I am not sure, and this could be rubbish.

After they change it all (on 998?) then some years later (once they are all out of warranty) someone will describe it in a book.
Until then, I dount we will actually get to the bottom of it.

 

[oldtimer]

sundeep, the engine design for the boxster/996 is different to that for the GT3 , turbo etc , thats why only the boxster/996 , and apparently 997 , are affected.

 

[Sundeep]

cheers chaps for the explanation....

1 in 4 is still very worrying......[]

maybe the next survey will be "of those effected, what action was taken to correct the problem?" [:-]

does anyone know what the figures are across other european countries ? ignoring the USA, as their warranty terms are more favourable to the consumer....

for example any data say from the Porsche Club Germany ? etc (assuming there is one) as I guess no data is available from Porcshe themselves...

 

[John Ware]

Add me to your list. The car is at Chiswick this morning having the 48k (at 25k in fact) and they called to say that there is a slight leak from the RMS (seepage rather than flood). They and Reading are happy for it to be left until the clutch needs changing (all of which I'll probably have done by Ray Northway). Not good enough in a car like this. Get it sorted.

 

[Guest]

The GT2/3 and TT versions of the 996 engine use the 993 block. The n/a 996 engine which is in the C2/C4/Boxster & 997 uses a new engine block. They are entirely different engines. It is ony the n/a engines that are having such problems. However, the none-n/a engines have had some RMS problems reported too. But RMS failures happen in most any engines (any marque) so this is to be expected. The problem is that it happens too often and too frequently in the 996 n/a engine almost to the point that it is a fair bet it will happen with these engines. The biggest issue is what long term effect the RMS problem has on a 996 n/a engine. Can it cause or lead to engine failure?, only time will tell. Will it reoccur once fixed, probably.

Mine is at my OPC as I write this having its 7th RMS fitted.

But I am now starting to wonder if half the "repeat" RMS problems are because the OPC engineer doesn't follow
procedure when they install the new RMS. For example, they are supposed to fit the seal dry (not pre-oiled). They
are also to be extra careful when handling the seal especially not to touch the outer lip. They are also supposed to
fit the seal using a special Porsche tool and it has to be fitted at a specific distance within the rear crankshaft bore cavity.
Then there are the "blue blots". These are 4 blue cloloured replacement engine block bolts and 3 IMS bolts. They are
specifically instructed to replace these when replacing the seal. But do they actually do this? My exerience is they don't.
And I surprised the service manager when I handed him the American Porsche TSBs that explain these procedures.
He had not heard of them or followed this procedure before but will follow up when replacing my RMS this time. It will
be interesting to see if the leak stops after they follow these procedures. He agrees that there is a chance that
by following these procedures the leak may stop. Could it be that PUK engineers are not up to speed with training?
I don;t know the answer but I speculate this may be the case.

 

[TISPKJ]

Nic please send me a form, I will soon be on my second one in my ownership.

Had only a minor damp patch never a drip, put in to replace after a year of arguing with Porsche over who was going to pay they finally agreed, had it changed not done 100 miles and now it drips all over the floor, back in next week for a new one.

 

[philippe]

Berny

I think you are right, I am sure there must be lots of engineers fitting these RMS and doing it the way they think best or should i say think would be the easiest route. It is a bit like if you get a flat packed pieces of furniture and it has fitting instructions most people would look at the instructions but would then ignore them if they think they can put it together without them and it may work but is not necessary the right way. I would be intrested to see if they do it correctly to see if it stops fingers crossed, lets hope the manager that you spoke to over looks the work.

Phil