IMS on a 99?
 

I've read somewhat conflicting reports on whether a 99 is or is not a good, 1% chance that is, candidate for the dreaded IMS failure. The readings I have made in favor of a 99 says that the design of the bearing, vs a 2000 to 2008(or was it 09?), insured that there was a very slim possibility of a failure. I think that I also read that the design change to the bearing was made sometime in the 99 manufacturing schedule. So if this is true then it seems that it would be a good idea to know how to tell if the 99 you were considering buying or owned had the older style bearing or the newer(bad) bearing. I would have to think this would be traceable by using the Vin# to look at Porsche's records.

Am I right in all this? Is there a published mfg date or set of Vin numbers or serial numbers that one could use as a guide?

I'd say just search the forum, but that actually may end up being more confusing.
The 2.5L engines (1997-1999) all have dual row bearings. They have a low failure rate, but have been known to fail. I have heard 1% to 2%.
2000 and 2001 2.7L and 3.2L engines may have dual row or single row bearings. There is a list of engine serial numbers, but it has been shown to be incorrect. The only way to be sure it to remove the transmission and look.
2002 thru 2004 models have single row bearings. Single row bearings have been reported to fail at 8% to 10%.
2005 may have a single row, or a non-replaceable oversized bearing. The oversized bearings have a low failure rate. You can read that they fail more often on cars that are frequently tracked.
2009 and later do not have an IMS bearing.

That may all be lies, but that's what I have read. :dance:

Thanks for that info. I did do a search and read a handful of threads. None of them offered the info you just gave me so I decided to take the easy way.

My 99 is a dual row. I saw the removed bearing. It was sloppy not staring to fail but ? 130kms. Dual row can fail too.

The 2005 -2008 M97 engines with the larger IMS bearing can have the bearing replaced. But only if the engine case is disassembled and split in half. So then you are rebuilding the engine. With all the new gaskets and other things that have to be replaced just to disassemble and reassemble, you may as well be replacing crank and rod bearings, rings, timing chain tensioners, etc. and checking valves, guides, cylinder bores to see if they are within spec. The idea behind the bigger bearing was that its larger diameter speeds up the movement of the ball bearings at any given engine rpm vs the smaller diameter bearings that were replaceable with the engine assembled.

Not to mention that any car this old could easily have a replacement engine and then all bets are off as to what bearing the engine has. Only sure way is to remove the transmission and inspect the IMS housing. Now if you know the history of the car from day one ....

Or if you have read the engine numbers off the sump rail, you can determine if it is a reman, or if not, what year it is.

Last Saturday I met and talked to a guy with a 99 base that had a failed IMS at low mileage. Less than 30k miles. Porsche replaced his engine under warranty but who knows what that bearing is. No engine is immune. My recommendation was when the clutch is done (low mileage, so it's still an original clutch @67k) have them see what bearing is in that replacement engine and be ready to replace it

Am I reading this correctly - Porsche replaced the engine under warranty - on a 18 year old car?

Sorry if I wasn't clear. While the car is 18 years old, the replacement of the engine took place a few years after pucrchase. Don't know exactly how many years, so I can't be more specific