***Non-Turbo 996 owners - Please read - IMS DATA REQUIRED***

[SilverCat]

IMS Data

date inputted: 11/08/15
member: SilverCat
model: 996.1 C4
engine size: 3.4
purchase date: 07/08/15
date registered: 01/01/1999
mileage (at purchase): 154,600
mileage (now): 154,600
bearing (orig./replacement): Unknown
failure data (if applicable): N/A
comment: Car thoroughly checked by Porsche tech last week - no sign of any nasties yet.

 

[cg1308]

date inputted: 11/08/15
member: cg1308
model: 996.2 C2
engine size: 3.6
purchase date: 23/07/2015
date registered: 01/03/2004
mileage (at purchase): 58000
mileage (now): 59500
bearing (orig./replacement): Unclear. Possibly replaced in 2009 at 31k miles
failure data (if applicable):
comment:
Service history has a bill for warranty part payment as goodwill towards RMOS replacement with inspection and work to the IMS mentioned. I was sold the car as having had the IMS replaced but what I can see looks as if they inspected the seals and changed some external gubbins around the IMS but not the part itself. Total of about £600 for the work (but at Porsche dealer so assume massive internal warranty work discount).
Who knows? I have written to the owner at the time so hopefully I will get to the bottom of it.

 

[Alex]

Porsche won't change an IMS bearing, only the full IMS assembly. Probably just had a new seal fitted on the cover plate.

 

[cg1308]

Porsche won't change an IMS bearing, only the full IMS assembly. Probably just had a new seal fitted on the cover plate.

Hmmm. So if I was sold the car specifically being told that the IMS has been replaced, and it hasn't. What should I do? I don't want to reject the car, it's perfect! but I did prefer that peace of mind and it did swing me from another car I was also looking at.

 

[Alex]

What does it actually state on the invoice? IMS bearing replaced or IMS seal replaced? The IMS is the 'Intermediate Shaft'. If they replaced that, I'm guessing the bill would've been around £5,000 not £500.

These engines are prone to the IMS seal leaking as well as the rear main seal (RMS) and would cost in the region of £500 to have them both replaced. Mine have been done twice.

IMS bearing is a completely different thing.

See this photo of leaking RMS & IMS seal

 

[Jmorgan93]

date inputted: 01/09/2015
member: jmorgan93
model: 996.2 C2 X51
engine size: 3.6
purchase date: 06/06/15
date registered: 14/03/03
mileage (at purchase): 58200
mileage (now): 62200
bearing (orig./replacement): Origianl
failure data (if applicable): N/A
comment: IMS plate and bolts changed at 37k with Clutch.


Edit made: I flicked through the cars history today and it was the IMS plate and bolts changed along with the RMS, Clutch and other jobs at once. Bearing therefore is still the original as far as i know.

 

[486ROB]

Ins Bearing Failure

996 C2 3.4 2000 W
Bought at 51k 2012,now at 68k
Original bearing & seal

 

[CarreraMonkey]

I'll stick my details on here for you.

date inputted: 07/09/15
member: CarreraMonkey
model: 996.2 C4S
engine size: 3.6
purchase date: 03/09/13
date registered: 30/07/03
mileage (at purchase): 86300
mileage (now): 114,500
bearing (orig./replacement): Original
failure data (if applicable):
comment:

 

[glenwells]

latest IMS pole

Hi,

Commend the time you have taken. I looked at the turedelta site and the info there (limited) points to the matter having peaked.
Hope I am not tempting fate!?!

date inputted: 16/09/15
member: glenwells
model: 996.2 C2
engine size: 3.6
purchase date: 29/06/15
date registered: 01/02/04
mileage (at purchase): 61,000
mileage (now): 63,000
bearing (orig./replacement): Original
failure data (if applicable):

My 2pennyworth.
The failures were/are more to do with tolerance variance at production (saving money). The failures in some cases caused by initially fractional movement of the bearing housing leading to increased stress and wear on the bearings themselves.
This then causes the increase in freeplay that then goes on to destroy the seal (leak of grease) then allows further accelerated deteriorstion of the bearing and the bearing race proper. It is not likely to be simply failure of the seals as bearings can survive with very small amounts of lubrication.

That is why there are differing mileages for IMS bearing collapse because they start at different degrees of tolerance, some will be fine some a mircon out of some much worse etc.
That is also why Porsche were at first wipping away defective engines and replacing them.
What 'premium' company would admit to poor quality components?
That would also explain why they reamined silent for so long. They did not know what the longer term outcome would look like in numbers of failures. It would not have taken long for someone to extrapolate likely failure rates and the then ever decreasing numbers of failures as time went on.

That theory would also explain why not all IMS bearings have failed. Those that had an acceptabel tolerance in regards to quality and 'fit' have stood the test of endurance as they were expected to.
All read the stories of bearings being 'upgraded' only to be told it was 'like new and seals intact'.

That may also explain why the instances of failure are tailing off. The cars are out of production for 10 years but still using a theoretical bell shaped graph it would show a peak of failure 'those that were going to fail' and then reduce as those that were ok reaming and others are repalced as precautions.

To cut a boring theory short. There are a number of factors at play. Quality of the parts. Maybe how you drive the car as low revs high gear
combinations would increase the stress on the relevant parts and if they were not as they should be increase the wear/damage.

On the upside. IF any of this theorisation were true then the higher numbers of failures that have been seen will not be repeated and although no guarrantees in life, other than death and taxes, those that remain are less likely to fail because they were ok in the first place.

A caveat to that would be very late models that have very very low mileages whose less than perfect IMS has not had enough run time yet.

A double caveat is that Porsche may at some point between 2001 and 2005 realised the issue and changed production or supplier. That may explain the other theory that there were higher instances of failure in 2001 and 2002 cars - again all theory - I do not work for Porsche. If I did I would be sneaking into the secrets room to find out the truth lol.

Regards
GW

 

[Alex]

Re: Ins Bearing Failure

996 C2 3.4 2000 W
Bought at 51k 2012,now at 68k
Original bearing & seal

Hi 486ROB, I can't use your data unless you give me more accurate details of the entries below:

date inputted:
member:
model:
engine size:
purchase date:
date registered:
mileage (at purchase):
mileage (now):
bearing (orig./replacement):
failure data (if applicable):
comment:


Thanks to all other members who've recently inputted data. Now have data from 86 996s. :thumbs:

 

[jaykay127]

Alex, just wanted to say, this is a great thread, thanks for taking the time to keep it all up to date.


date inputted: 21 September 2015
member: jaykay127
model: 996 C4S
engine size: 3.6
purchase date: 26 August 2015
mileage (at purchase): 89600
mileage (now): 90500
bearing (orig./replacement): Original
failure data (if applicable): N/A
comment: Car has full service history and at no point have the IMS nor the RMS been changed.

 

[Alex]

jaykay127

Forgot to put date registered

 

[jaykay127]

Sorry

Date registered 4th July 2002

 

[Alex]

Sorry

Date registered 7 July 2002

:thumb:

 

[Robertb]

So... any makings of a trend and a theory from your data yet Alex?

Edit to add, sorry just read your post on the previous page!