I'm looking at a 2001 S with about 60k miles. It is in great shape, a color I like, optioned really nicely, has maintenance records, etc but does have an oil leak between the engine and trans (6-speed). It is on the original factory IMS bearing. The oil leak is thoujght to be RMS, but from what I've read it could very well be the IMS bearing itself leaking, which I believe means it could be near failure. The owner has monitored oil filters for debris and they look clean, but who knows. I'm trying to gauge the risk that the IMS bearing is about to fail. Should I buy it and drive it and not worry? Should I buy it and immediately replace the IMS bearing? Should I skip this one and keep looking? Thanks

 

If you buy it, I’d replace the bearing. Great peace of mind.

 

The IMS doesn’t leak, it’s a grease-filled roller. It’s the RMS that can fail and allow oil to wash out the grease. If the RMS is failing I’d play it safe and budget for IMS replacement. Change the clutch while the ‘box is out. If condition reflects the low mileage, and the price is right, you could end up with great ride

 

A leaky RMS (which is the crankshaft seal) does not impact the IMS bearing, which is on the intermediate shaft, which sits below the crank. The IMS bearing has it's own seal (which helps contain the bearing grease) which can fail, initiating bearing failure.

I wouldn't let a leaky RMS stop you from buying the car, if everything else looks right. My RMS has been leaking since Clinton was president. When I change the clutch, I'll fix the seal, and consider the IMS.

 

Yep, was thinking of the IMS seal If that’s leaking the bearing is likely compromised. Definitely worth haggling on the price

 

Just to clarify a couple of things. The IMS bearing is below the crankshaft and is bathed in oil when the engine is not running. The flange that positions the bearing has an o-ring in the early version (changed to a ribbed seal in later versions as I remember it) and the o-ring can leak, which means nothing... except that the o-ring is leaking and has nothing to do with the condition of the IMS bearing. IMSBs start out packed with grease but the grease has long since washed out by now for most of us. Post #8 of this thread has some interesting info from a contributor to the forum who has lots of experience with the IMSB.
http://986forum.com/forums/performan...nt-thread.html
There is a fair amount of information with some links in the thread.
If the IMSB is seriously failing I imagine it can impact on the flange and cause a it to leak.

A 2001 may be either a double row or a single row IMSB. How old and in what condition is the clutch? If it is getting on in years and wear I would think in terms of a clutch job and RMS replacement. With the flywheel off the IMSB can be inspected to see if it is single or double row and for wear. If it is a double row and in good condition I would remove the outer seal and leave it alone... but that's just me. Would you be paying someone to do the work or would it be DIY? How resistant to stress are you?

 

Ditto to this.

I was living in a condo and my RMS was leaking, leaving a lot of spots on the floor and residents complained to the condo board. My hand was forced to get the RMS replaced or the leak contained so that was when I got the IMS replaced at the same time. Had it not been for that, I would have just left it alone. 1.5 years later, my RMS is dribbling again. The only way to stop it was to drive the car. Letting it sit was the worst thing I did to this car.

 

Thanks for the info, and that link - good info there. I also saw info from PCA in this video - where they say a failing IMSB can cause the flange to leak and present as an oil leak that is thought to be RMS but is actually the IMS bearing. I just don't want to buy a car and have a catastrophic engine failure right away. No way to know with certainty without inspecting (or replacing) the IMSB, and that won't happen on this car because the clutch is reported to be in good shape and no reason to pull the trans. It sounds like it is just a risk with these cars with no real way to measure that risk on any individual car. I may have to accept the risk and then plan to change the IMSB and RMS when it is time to change the clutch, which might be a while. This is the same for any car on the factory IMS bearing.

 

Oil can leak from the IMS flange when the rubber seal is compromised. The IMS bearing is partially submerged in oil. A lot of people think it's always the rear main seal, but drop the transmission and find the oil is coming from the IMS flange.

Porsche even sells just the flange for this purpose.

 

Irregardless if it's a dual row or the most problematic single row 6204 IMS bearing, the engine has been in service for more than 20 years. If you buy this car, make plans to change out the IMS bearing, RMS, AOS, and clutch kit. Those are the basics.

Cheers!

 

I'm largely indifferent and unafraid of IMS problems. But a 60k mile car isn't past the 100k 'all clear' rule of thumb that I use. I'd figure on replacing the IMS if I was interested in this car. Figure that into your offer.