IMS Bearing, I'm a 99 Percenter
 

2000 S with 113K.

I replaced the clutch and while there wanted to deal with my IMS bearing fears. I had read somewhere, maybe of this forum, that the true failure rate on the dual rows was ~1%, and the single row 10%. I do not know if this is true.

However with the cost of failure being so high, I went with the LN pro solution.

Bottom line, the factory bearing was in great shape, I replaced it anyway.

IMS Bearing
 

According to the articles that I have read, those numbers are commonly quoted. At the end of the day, is the incremental cost of the IMS bearing upgrade worth the "peace of mind" to you?

Personally, I would do the upgrade vs risking grenading the engine and dealing with a much much larger repair bill...

Also, from a resale perspective, knowledgeable buyers will pay a premium for an IMS upgraded car or at least consider purchasing it because it had the upgrade addressed.

These cars have such a bad rep with the IMS. It´s always nice to hear that not all of them are rolling grenades.

did you have a single or dual row in there once it was removed?

I change these out for a living, and the retrofit process is designed to be a proactive step, not a reactive one. Of all the bearings we have pulled, probably 95% were in good shape. But that does not mean anything, as the time frame from when one starts to go, to when it totally fails is not a big one; once on their way, these things crap out really fast, which is why they give little if any warning to owners.

+1 - absolutely right!

My 2001 Boxster S has 111,000 miles on her. If, IMS failure was going to happen, it happened long ago and I've no record of that from past owners. There was an issue early on. An issue so severe that there was a class action lawsuit. But, most of them happened below 40,000 miles. If you drive a Porsche like a Volvo expect problems.

JEP in PA,

I recently bought a replacement 2.5L with 84K miles on it the listing said "it has already the IMS updated to the new Porsche factory IMS." What does this mean to me? Am I safe to not replace the current IMS?

While this engine should be a dual row, it also means it has the same factory bearing in it, only newer. If it were mine, I would put one of the ceramic hybrid's or even the IMS Solution in it before putting it in the car.

I dont see a problem with volvo driving

http://highspeedfotos.de/Coppermine/...s/IMG_3697.jpg

The most likely failure mode begins when IMS seals degrade to the point where the bearing grease washes out but not enough splash oil gets in to lubricate it. Seals in low mile cars, whose seals sit in contaminated oil for long periods, see this mode early on.

Seals in high mile cars with frequent oil changes degrade much more slowly, which gives rise to the myth that once you past a certain point your IMS won't fail. Nevertheless, they still degrade. Eventually, these cars will see their IMS bearings fail. For this reason, one should change the bearing at the time of a clutch changes and leave the outer seal off.

I've the Tip, but when reading about the IMS the recommendation is to swap it out coeval with a clutch change.

Does this mean the Tip is less susceptible to a failing IMS?

Thank you.

No, It just means there is no clutch to change so one less reason to go in there. There is no evidence or reasoning to believe the tip models are less prone to IMS issues.

I was told by a service tech in Carlsbad that if your 986 has more than 75k miles without a failure, the odds of it failing is less than 1%, though he did say that it would be prudent to do the upgrade with the next clutch change for that peace of mind.

That is complete nonsense. We have seen no statistically significant relationship between mileage and failure rates.

Jfp, would you elaborate on this for us, please?
General consensus all over the internet seems to corroborate what the mechanic told him; if your IMS hasn't failed by xx miles (I've read anywhere from 60k to 75k) then it's very unlikely it WILL fail.

I value your knowledge, as it's based on real experience, rather than just what I've read, haha. Can you tell us what's behind this idea, and what your own experience says are real factors?



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Over the years, we have see several IMS failures, which were confirmed by at least a partial engine tear down (we don't say IMS failure until we know it was). The mileage of these cars were all over the place, some were 'garage queens doing less than 1K miles a year, others were daily drivers with well over 100K miles on them at the time of failure. If you looked at the confirmed failures we have seen, while the mileage data seems almost randomly scattered, one very obvious similarity was that most were single row engines, with only a smattering of dual rows, similar to the data published in the factory's legal case. An outlier in the data was one owner that had a relatively low mileage failure, he had a higher mileage replacement engine installed, only to have that one fail many thousands of miles later. Last I heard, he was driving a Nissan.

On the basis of this experience, I don't see a mileage relations relationship. Other shops may or may not have had a different history, but we don't go by unconfirmed chatter off the web, I can only speak for what we have seen.

Thank you.
And the delineating line for when a shingle row was used, rather than the dual row? Do I understand this happened mid - year '02?

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No. The transition period was the 2000-2001 years; with either year, you can have either a single or dual row, and the only way to know is to pull the car apart and look, regardless of what the internet chatter thinks. I personally own a 2000 and 2001 M96 engine cars that were both purchased new. The 2000 car is a very early (in the model year) car, and it was a single row. The 2001 was one of the last built that model year, and it was a dual row, which is exactly backwards from what a lot of people think it should be. Both now carry IMS Solutions.

I've heard the mileage failure rate nonsense for years and have always quickly dismissed it as it's just counterintuitive to common sense, or at least to my limited version of "common sense". I'd agree that low use cars (and bearings) are (or can be) subject to failure for many understandable reasons, but the logic of thinking "I've made it to xx,xxx mi without issue, so I don't need to worry about it" is just plain dumb. It's a bearing, under load and with friction...it will fail; and the longer the bearing is subjected to wear, the greater risk of failure.

To use an analogy...let's say that you purchased tires that you discovered had a known design failure and that you had heard that the failure *usually* happened under 1,000mi...if you continued to use such tires, would you think "I've made it to 50,000mi, I guess my tires are good" and continue to blissfully drive along? Of course not. Tires wear, and the wear is visable. Just because a component is buried deep and out of sight doesn't mean wear isn't slowly degrading the functionality and shortening the lifespan.

I can understand trying to find comfort and console in a belief to to mitigate fear, but those who wish to follow the "high mileage IMSB" preachers are *ahem* delusional. Please accept my most sincere apologies if I have offended, but please, don't just believe something because you want it to be true.

Of course, I am fully open to meaningful contradiction. My complete and total wrongness on any given subject only leads to a learning experience. ;)

It makes sense if the failures are related to a production flaw, but not if they're due to a design flaw.
Hear me out:

If the failed IMS bearings were all from a certain oem supplier, or from a certain set of date codes, then one could have faith in the idea that "if it hasn't failed by xx miles, it won't". We could imagine that, nestled deep in the motor, is an IMS from a different OEM, or a different date code.

If, however, the failures are due to a design flaw, then the number of miles should serve to INCREASE likelihood of failure. (Because, as you say, the longer it's stressed, the more likely to fail)

To be honest, I don't know what to make of "no correlation to mileage", other than the frequency of failures must be so profoundly low as to be too small a sample to track trends.

??

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I won’t expect tires to last over 50K miles on my Boxster, not even close. But I do expect my original IMS bearing to last 100K miles or more by design, specifically the original dual row bearing.

Incidents with downgraded single row design exposed potential weakness in the system but I find some truth in someone suggesting less failure expected once past 50-75K miles for the double row. Early bearing failure may signify quality/ tolerance issues, but bearing life could be infinite when lubricated properly and loaded below its capacity, like many other components are originally designed for under ‘ideal’ conditions. Tires just wear out no matter what...

After all, this issue comes down to half glass full or empty... not a single answer for all. Personally I have no fear with my original double row bearing, just keep my oil fresh and full and drive the car the way it is meant to be, almost daily through the year and enjoy every second of it. I may think about it if my clutch needs replacement but good chance that I’d still leave it alone... it has ONLY 83K miles!

I am the original poster, it was a dual row, likely did not need replacing however I have the piece of mind now. BTW, pulling that bearing was no small task, I destroyed 3 tools b4 success. That inner spring clip was a bear. A machinist friend took the challenge personally and fabbed a puller that worked.

There are so many variations and no central authority tracking things. Porsche didn't for a long time want to know for legal reasons and fixes were, until recently, not Porsche developed or approved. Nor could they know all as replacement engines were frequently third party installations from wrecks.

First there are production variations. How do the crankshaft and IMS mounting holes line up in the block. Then the parts variations, thing like the trueness of idler pully bearings and such. Then the randomness of manufacturing tolerances in the bearings themselves. Now throw in weather conditions, driver techniques, oils used, oil change frequency, etc.

I've seen postings of 10k failures and 350k non failures. Two on the same car. Every transmission. Everything else clean. Everything in the engine trashed.