I am not so sure that the rate of failure is as small as mentioned in this thread. There is a well publicized class action lawsuit that Porsche settled, so clearly, it must be a big enough nuisance. 2% will not warrant Porsche settling the case.

It's an upside and downside situation. Upside of not doing the IMS is a saving of what? $3k. $5k if you do IMS, RMS, AOS, clutch all at once. Downside is a blown engine and a minimum of $15k AND a significant hit on resale value because you have a replacement engine and a story to explain to the next buyer. I wouldn't go anywhere near a car with a replacement engine, because you never know what else needed to be/was replaced along with the engine.

I have also heard (this is anecdotal only) that garage queen cars that sit a lot are more susceptible, because the bearings aren't lubricated as intended, as they are designed to be on a daily-driven car.

Just my two cents.

 

Congratulations and welcome to the 6!! It looks like you found a beautiful example, and only 10k on the clock. Were you looking for a while?

 

Hi

Yeah I was looking for close to two months.

 

Great purchase! Nice looking car, congrats!!! And welcome to the club :-)

 

There are documented cases of IMSB failures even after the installation of the LN Engineering upgrade. Jake Raby made a post about it on rennlist. I believe he said that there were six known failures, and they all could be traced to improper installation. It's important to have the upgrade done by a knowledgable Porsche mechanic.

I drove my car on the original IMSB for over 120K miles. I had it upgraded when my clutch was changed. According to my mechanic, there were no signs of impending failure of the original bearing based on his inspection (he didn't actually cut the bearing open and inspect it internally).

You'll never find a definitive answer on whether you should replace the bearing or not for your car. You'll find cases where people have had no issues, and you'll find cases where the bearing has failed early. You have to take in all the information and make a decision based on your tolerance for risk. Personally, based on everything I've read or heard about, I would have it changed proactively. I feel that the risk is relatively low, but the consequences of failure are dramatic. That being said, I wouldn't fault you if you decided not to have it changed. It's your decision. In the overall scheme of things, it's not that expensive.