Replacement Schedule for IMS Bearings

[RNajarian]

I received an email from our host this morning informing me that it was time to replace my upgraded IMS bearing.



My bearing was done in 2020 and the car (a 2000 996 Carrera) has only 4000 miles on the replaced bearing.

What is the current thinking of the brain trust? If the bearing has low miles but has “timed out” (year wise) is it critical to replace the bearing?

Thanks for your expertise.

[OldSharp997]

You ask a great question.

What is the failure mode(s) for the "timed out" bearing (with low miles)? Are there any other (failure) statistics available for any of these (non-IMS Solution) replacement bearings?

[inaminit]

I read the same email and had the same question: if the bearing is made from ceramic and metal parts, how then will some of it decay or degrade in 5 years so that it is no longer functional? Is it metal fatigue from gazillions of stress cycles? And what about a bearing still in its oe packaging that has been sitting on the shelf for 5 years?

[RarlyL8]

IMHO this is complete BS, a money grab.
I've had the engine out of my 996 twice for regular maintenance and both times the IMS bearing checked out with no signs of issue. I've spoken to several mechanics at different shops (we do business with shops all over the world) and they tell me if it ain't broke don't fix it. They warn that you are opening up a can of worms when replacing these which can possibly cause more harm than good if no signs of wear are showing. Their advice is to change the oil regularly and have the oil tested.
You do what you want; if the engine is coming out for service anyway and you're antsy about the IMS then go for it. If not it's an expensive PM that may not be needed or at worst could cause a leak that leads to another engine out to fix.