Tiptronic and IMS Failure

[rexcramer]

I have read multiple threads, visited several vendor sites and spoken to a local German car specialist (who has worked on my car) regarding the IMS bearing and possible failure. There seems to be several points that are echoed across the various ‘experts’ forums;

1. IMS failure is +/- 10%. (Unless it’s your and then it’s 100%) C’mon, fess up Porsche, what are the real numbers?
2. Lugging an engine is hard on the internals. I understand how torque/HP curves work and that makes sense.
3. Ergo, Boxsters that are driven hard are less prone to IMS failure. Or so suggest the ‘experts.’
4. Low mileage cars can somehow contribute to IMS failure. This seems like fuzzy logic.

In full ‘auto’ mode, my 97 (16K on the odo) really likes to shift low in the RPM range. Usually shifting under 2k, unless I put my foot in it. I can still be under 50MPH and it will shift up to 5th.

I usually only put it in ‘manual’ mode when I am in the twists’ or mountains and keep the revs above 3K.

So the question to my colleagues is do cars with ‘Tips’ have a higher IMS failure rate as the data would suggest?

I should probably just go for a drive and quit overthinking this.

[Timco]

Go for a drive.

If it worries you, yank that trans and swap it and be done. Do RMS and flush trans /filter if they use one. Do boots, CVs, Cat Deletes, and go crazy while you're in there. New drop links, sway bar bushings, all that stuff.

[Giller]

I've heard lots of people say the Tip is LESS likely to get the failure. I've also heard the failure rate is way under 10%. I've also heard......
There is no hard data. Many many people have changed out their IMS and it was perfectly fine. Many have not and it went boom.
Roll the dice and just choose. No one here can tell you if your IMS will blow up or not. It just either will, or it won't.
The odds are still in the "it won't blow up" camp...as even using your 10%, that means 90% won't blow up.

[JFP in PA]

Originally Posted by rexcramer

I have read multiple threads, visited several vendor sites and spoken to a local German car specialist (who has worked on my car) regarding the IMS bearing and possible failure. There seems to be several points that are echoed across the various ‘experts’ forums;

1. IMS failure is +/- 10%. (Unless it’s your and then it’s 100%) C’mon, fess up Porsche, what are the real numbers?
2. Lugging an engine is hard on the internals. I understand how torque/HP curves work and that makes sense.
3. Ergo, Boxsters that are driven hard are less prone to IMS failure. Or so suggest the ‘experts.’
4. Low mileage cars can somehow contribute to IMS failure. This seems like fuzzy logic.

In full ‘auto’ mode, my 97 (16K on the odo) really likes to shift low in the RPM range. Usually shifting under 2k, unless I put my foot in it. I can still be under 50MPH and it will shift up to 5th.

I usually only put it in ‘manual’ mode when I am in the twists’ or mountains and keep the revs above 3K.

So the question to my colleagues is do cars with ‘Tips’ have a higher IMS failure rate as the data would suggest?

I should probably just go for a drive and quit overthinking this.

Failure rates are a matter of probabilities, not transmission type. One of the most enduring comment is that running these engines for prolonged periods in certain RPM ranges seems to be involved, probably due to internal harmonics. Otherwise it is a simple probability calculation.

[Luv2Box]

Your Tip's ECU uses fuzzy logic to determine how it will shift in D mode based on how you drive the car. If you putter around it will shift quickly into 5th gear to get the best fuel mileage. If you start driving it with a heavy foot it will adjust to go to redline for more performance. I leave mine in M all the time to keep the revs above 2K rpm as LN suggests when their IMS is installed.
There is hard data on the number and percentage of IMS failures that were reported in the class action lawsuit against Porsche over the IMS failures in model years 2000-2005. Failure rates reached as much as 10% in some of those years and the suit involved 52K vehicles and the largest number of failed IMS was in California. Model years '97-'99 had a failure rate of 0.2% and were not included probably the double row IMS had something to do with the low failure rate.
No breakdown of failure rates were categorized by transmission type, however, I've also read that Tips have a lower failure rate and fewer camshaft deviation issues than sticks but that is unsubstantiated due to lack of real data.
IMS failure does not seem to favor lower mileage vehicles over high mileage or slow drivers over fast drivers it appears, from the lawsuit data, that it is largely confined to the 2000-2005 models probably due to the shift from a dual row to a single row bearing.

[JayG]

Whoa Trigger...

10% failure?? where are those numbers?
My understanding after sifting through all the crap is a failure rate much lower than that, some claim around 1-2% others as high as 10%

There is SO MUCH misinformation on this subject that no one really knows the facts

here is a really good article on the IMSB issue. Now bear in mind, it was written by LN, so they do have a vested interest in bearings being replaced.

IMS Bearing - The Full Story | Oregon Region Porsche Club of America

[JFP in PA]

Originally Posted by JayG

Whoa Trigger...

10% failure?? where are those numbers?
My understanding after sifting through all the crap is a failure rate much lower than that, some claim around 1-2% others as high as 10%

There is SO MUCH misinformation on this subject that no one really knows the facts

here is a really good article on the IMSB issue. Now bear in mind, it was written by LN, so they do have a vested interest in bearings being replaced.

IMS Bearing - The Full Story | Oregon Region Porsche Club of America

The data is right out of the class action lawsuit. 1-2% for dual rows, 8-10% for single rows.

[Jake Raby]

Tips make up a much smaller percentage of cars manufactured. They fail too, you hear less about it, because of the lesser amount of cars.

IMSB failure has no prejudice, you either got a good one, or you got a bad one; you either have good luck, or you don't. Some things can be done to make your chances better, but its still all luck.

BTW- That article wasn't written by LN. The pics and some information were compiled from our research, and LN.

[rexcramer]

Thanks everybody for your input.