IMS again

[Subman]

I just had the LN IMS Retrofit done on my 02 Boxster S at 115,000 miles. When it came out the original IMS bearing was, in a word, perfect; it was in like-new condition. Still happy I had it done.

I intend to do the same thing in the spring on my 00' Carrera with only 34,000 miles. There are zero signs the car needs it; oil change at purchase showed (when the old filter was cut open) zero particulate inside, and the car's been dealer serviced regularly. Nonetheless it'll get done.

It's a really simple equation.

1. There's a (low) failure rate of some number with these bearings, and there's no accurate data on what percentage will fail. There's also no accurate predictor as to which cars are going to fail (high miles vs. low miles, single row vs. double row, oil changes at X miles vs. Y miles, etc.)
2. The vast majority of IMS bearings won't fail (as evidenced by mine, which was a single row in great shape after 115K).
3. Resale value of cars with IMS bearing replacement is higher.
4. Having the bearing work done eliminates "not knowing" how your bearing looks. That in a nutshell is why I did mine and why the 911 will also get the work done. Simple peace of mind.

There's a lot of subjectivity, and there's no right or wrong answer. If someone decides not to replace their bearing based on the low failure rate, clean oil filters etc., that's a pretty good plan with a high chance of success. And if someone (like me) decides to go ahead with replacement based on the certainty a new bearing provides, well that's OK too. Do what works for you and enjoy the car.

[pilot4fn]

Thanks Subman, good points. I'l probably get the IMS bearing changed at the spring as I get the car out from the garage (currently hiding from the snow)

[piper6909]

Originally Posted by pilot4fn

Thanks Subman, good points. I'l probably get the IMS bearing changed at the spring as I get the car out from the garage (currently hiding from the snow)

Subman makes some good points, but consider the cost vs benefits. You can get a good used 2.7 motor from $1500-3000 depending on location, miles, etc. An IMS will cost you around $1500. So you're looking, at best, at a 2:1 insurance policy against, at worst, a 15% chance the IMS bearing will actually fail.

Is it worth it?

I have a 2002 with 93K miles and Tiptronic. If I had a manual and needed to change the clutch, the IMS bearing may have been a "while you're in there" sort of thing. I don't, so it's not worth it for me.

[maytag]

Originally Posted by piper6909

Subman makes some good points, but consider the cost vs benefits. You can get a good used 2.7 motor from $1500-3000 depending on location, miles, etc. An IMS will cost you around $1500. So you're looking, at best, at a 2:1 insurance policy against, at worst, a 15% chance the IMS bearing will actually fail.



Is it worth it?



I have a 2002 with 93K miles and Tiptronic. If I had a manual and needed to change the clutch, the IMS bearing may have been a "while you're in there" sort of thing. I don't, so it's not worth it for me.

FWIW, when I installed a used motor, 78k miles, into my '03 S, I elected NOT to replace the IMSB. There are so many things that can take out these motors, it seems the IMSB has a relatively low failure rate, comparatively. (When all is taken in aggregate)
Why bother?

Sent from my SM-G970U using Tapatalk

[mikefocke]

Of course there is always the chance that the new bearing is bad (low, perhaps, but always a chance) or the installation flawed.

There is accurate failure data from Porsche as revealed in the lawsuit. Only accurate as of the date of the lawsuit which is a long time ago and more cars have accumulated more miles since then. So are the failures higher now? One would think so as more cars are at greater mileage than was factored into the original admission by Porsche.

[BoxMann]

Originally Posted by mikefocke

There is accurate failure data from Porsche as revealed in the lawsuit. Only accurate as of the date of the lawsuit which is a long time ago and more cars have accumulated more miles since then. So are the failures higher now? One would think so as more cars are at greater mileage than was factored into the original admission by Porsche.

From everything I've read, failure rates for the Gen 2 bearing are anywhere between 5% - 20%. Pick your lucky number. IIRC, 8% was the number in the lawsuit, but that's on limited data that existed at that time, and therefore, should not be applied or relied upon universally.