Intermediate Shaft Bearing Question, once more

I know this ISBearing been very extensively covered, but do we have any data on the likelyhood of issues associated with late 2000 engines - like 2007 & 8's? Is it prudent to have the bearing replaced or is the bearing in these cars the same than what is used in the eary model 996's? I understandmodel year 2009 included the change to the engine design that eliminated that problem (997.2). Thanks

After 2005 and until the advent of the 9A1 engine in 2009, Porsche used an oversized IMS bearing that cannot be changed out without totally disassembling the engine. And, yes, the oversized IMS fail as well.

For the results of an unofficial, statistically insignificant poll of 513, and counting, owners of 997 look here. IMS failure for your 997 car, Y or N? tell us (yr, 997.1, .2, m96, m97, failure mode) - Rennlist Discussion Forums

Does the 2004 GT3, with a different engine, also have the IMS bearing failure of the C2 and C4?

Thanks JFP & Frank! JFP: That is consistent with what I picked up previously, TY. Frank: That's some interesting data, obviously not scientific, but good data points. Too bad someone can't mine that data to determine the characteristics of the car at failure and non-failure. We know it's design but is it maintenance, mileage, hard driving, geographic location or what, that drives the issue? I did't go through all the posts over at Renn.. , but I would be curious about how many high mileage 996/997's are out there and their failure rate. Thanks again guys! Gary enough.

yelcab Dude, ur hijacking my post. Interesting question, and cool cars... Maybe reformat question to be consistent or post new one. Let's get thru this...

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GT 2 & 3 use a different engine than the C 2 & 4. They have lay shafts, but use pressurized oil fed bearings.

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Hey, sorry. I thought you got your answer. The 997 from 2005-2008 use an oversized bearing, but it also fails at a non scientific rate of 5%. Ir is enough of a problem that PCNA approves replacement of engines when that happens out of warranty. That means it is a design problem.

Thanks YelCab! Do you have a link to further information on the engine coverage for 2005-8 from PCNA?

There is this for earlier cars. I would bet (not much) that as soon as the 05 -08 IMS equipped cars are more than 10 yrs old Porsche will retroactively cover them. 10 Years because the number of units of exposure, IE failed engines, will be a known quantity. If too many maybe no coverage extended?? IMS Class Action Suit 2001-2005 owners win. Update Mar 12 IMS Class Action Suit 2001-2005 owners win. Update Mar 12 - Rennlist Discussion Forums

Thanks Frank Good point about the 2005-2008 pcars. I'll read or skim the text of the suit but I think the issues would be, if a purchaser of the used vehicle buys it knowing about the issue, then the lost value, in part, would be on the seller as the price would have been adjusted downward due to knowlege of the issue. I will PM yelcab1 to see if he has further data on his post. Nonethless, thanks for the posting! Gary

In this link: http://forums.rennlist.com/rennforums/997-forum/629870-ims-failure-for-your-997-car-y-or-n-tell-us-yr-997-1-2-m96-m97-failure-mode-21.html Look at page 21, post 306, where the 2005 fails out of warranty and Porsche agreed to a replacement.

Thanks again, yelcab1!

Historically Porsche would replace select out of warranty engines. But it was not a given. Now that 2001 - 2005 owners have won a lawsuit Porsche might cover more "out of warranty" 2006 - -2008 cars. But once again not a given. You will still have to fight for coverage which may be more forthcoming if you have a good long term relationship with your servicing dealership. In other words don't count on it.

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No - different engine design - does not have an IMS. *Does have an issue with coolant pipe breaking...

The data that was given out in the discovery phase of the lawsuit that is supposed to show that single row bearings fail anywhere from 8% to 10% (location dependent for some reason) and double row under 1% does not take into account the dealers that pulled engines based upon an early Porsche diagnostic (simple) process that was later changed to require dealers to actually pull out the bearings to check before they ordered a new motor under warranty. In the first few years of Boxster and 996 bearing issues - Porsche found after tearing down the returned motors that a significant (to them) number of engines actually had issues unrelated to the IMS and that the bearings in many were fine. Now it`s debatable if an engine with a D chunk issue or cam chains falling off would have been swapped out for a new motor or not - most likely yes - but the point is that it does tend to swing the IMS failure numbers higher in the earlier stages (some suggest 2001 was when Porsche changed diagnostic procedures) and this could affect these stated percentages in this lawsuit. I`m one of the 1% crowd who decided I would change out my 99`s double row bearing last year - just because. It turned out the bearing was fine but I changed it for the LN bearing and treated it as maintenance. I think the number of people who will be able to take *full* advantage of the low (to me) amount of $6500 after an engine blow up will be quite low when you take into account of the *clauses* in the proposed settlement. FYI: This lawsuit has not been settled as yet.

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No

I have a 2001 996 with 105,000 miles. When I tried to join the class action lawsuit, the serial number of my car precluded me from joining for some reason. I have never done any remedial work on my IMS bearing, but have faithfully changed the Mobil 1 0-40W oil at 10,000 miles or 2 years.