I was reminded about this old thread a few weeks ago when I was out at my friend's shop at Willow Springs. I handled probably 6 or more failed or imminently failing IMS bearings.

They ranged from a little loose and not smooth spin to flopping all around to loose and catching as you spin. Any of these would be taking out the engine really soon had they not been replaced.

I watched a double row IMS being replaced in a Boxster, actually went pretty quickly. That one was purely preventative and had no actual play or issues in spinning when it came out.


Our M96 motors are no longer a black box mystery. A body of knowledge is now out there. There are things on it that wear out and take out the motor if not addressed. Just like any other motor porsche or otherwise.

Even the venerable GT3 Cup motor has a very well defined rebuild window measured in operating 'Hours'.

My 2 cents

 

So if you think that the best way to install the bearing is without seals,
do you think we need to clean the grease before?
I'm not sure if this grease could contaminate the clean engine oil...

And... could the oil passing through the bearing (without seals) get into the IMS tube?

Thanks in advance for your reply, Jake. I'm one of those who think that you're giving us a great support.



I think 0W40 is too thin and properly for cold climates.

after reading LN/Raby's advices about lubricants, I'm going for Valvoline VR1 5w50.

 

Ok, so i have read the entire nine pages of comment, one thing I practise that I have not seen addressed is Oil Analysis. I have a 2001 996 and i use Mobil One 0-40 changed at 5000 miles, then send off a sample to blackstone to get analysed, I rely on the fact that as everything seems really healthy right now and the analyses are complimentary about the engines condition, could the bearing get to the point where it fails completely and causes catastrophic damage to my engine in less than 5000 miles?. I was hysterical about the problem until i went this route and I'm wondering if my new found confidence is warranted?.

 

Early '99 owner (May '98 build) and new member here. Bought car in 2004. Don't really know if the motor is a replacement or original. Car now has 33k miles. No visible leakage from RMS and bottom of motor is dry. Just changed oil. Used 15w50 Mobil1. Old oil and filter looked clean. After going through these 9 pages about the IMS bearing I feel a little sick. I "had" planned on keeping my car for a long time since I love it and it's in pristine condition and runs as new. But now I feel like I'm always going to look at it like it's a bomb about to go off. Did I read that replacing this IMS part runs close to 2K dollars? My dilemma now is should I spend this kind of money to get over the "sick" feeling or rationalize the anecdotal odds and hope for the best?

 

I have raced my '99 car HARD for the last 3 years. 4 hour enduros in 105F ambient heat etc.
We change the oil (Motul 300v) every w/e and cut open the filter to look for bits. So far so good.
My mechanic posits that its tied to Porsche going to overly wide oil change guidelines back in the late 90's. He may be right but how are you going to test that theory.

We are just about to pull the motor- if there's anything of note I'll post here.

There is no data on IMS failure. Equally there is no data on how effective the cure is. Intuitively it makes sense but may be (may be) unnecessary. Ultimately its for you to decide, but changing your oil frequently and keeping and eye on the RMS , drain plug and oil filter can't be a bad thing.

Best of luck (to us all).

 

There is no data on IMS failure because IMS failure does not exist. There are many many things to be afraid of with regards to your high performance flat 6 engine (D-chiping, cracked heads/valves, cylinder ovaling) just not IMS failure.

 

Trapper, I have an early 99 as well - I think an August 98 build. One thing to remember in all this is that the early motors (installed in 1999 and 2000 MY cars) used a dual row IMSB. Anecdotal evidence seems to be that the dual row bearing motors seem to have experienced far less bearing related problems than the 2001 and up cars with the single row bearing. I'm like you and didn't know about the "issue" until after I'd bought my car (at 28K miles). I've had it now for 4 years and it has about 43K miles on it. I intend to keep it for a long time. Just change your oil often and check your filter after every oil change for debris. There are lots of cars out there that have gone into the high hundred thousand mile mark and beyond.

 

Wonder what the IMS failure ratio is between daily drivers and garage queens.

 

I took my car in today to have my IMSB done as a precaution since my car has been a "garage queen" for most of its life and the owner of the shop (Redmond European in Redmond, Wa) showed me some recent IMS's he has done, one he said had the ***** fall on the ground as he pulled the IMS cover off (double row), another he showed me was all dry and loose and sounded gritty (single row) definately feeling better about my car now that I took the step to do this......to me 2k is quite a bit for something that may or may not fail but I look at is as a type of insurance....

 

If the bearing was as easy to change as an oil filter then there would be no 996 on the road that didn't have the upgraded bearing. There would be no cheapish 996 to buy. I love the scare mongers. It was the scare mongers that made it possible for me to afford a top class sports car. WE are not all highley paid Doctors, surgeons or executives on this board. The top and bottom of this discussion is, some of us don't have that kind of money to outlay on something that probably wont happen. Don't we all take a chance every day of our lifes? From the moment we rise in the morning we take a chance that we are still alive at the end of the day. My preventative measures consist of checking my oil filter, Changing oil at 5000 miles driving the hell out of my DD and thats about it. I refuse to live in the wreckage of my future. Thats not a good place to live. I live in the wonderful moment of driving a convertable 911 Porsche, something I have wanted to do for the past 50 years but could never afford one. The scare mongers made the 996 possible and I thank them so much. So thanks to Flat6 Innovations and Jake. I hope I never need to use you. Oh musn't forget to take my 6 daily tablets to keep my heart ticking lol

 

BTW how was the condition of yours.. Don't need to ask or you would have said how bad it was. I have an extended warranty which came on my car with 35000miles or another 2years left. I already used it for a new gear box last june and I am driving like a maniac to make the car break down on me. No luck so far. Well.....got to get my moneys worth. Like the guy that had to have his car towed off the turnpike for $500. He kept his foot on the brake just to get his moneys worth.

 

Everything fails eventually. M96/M97 engines have a remarkably reliable track record. There are something like a half million on the road. If there weren't a few hundred horror stories out there, it would almost be more suspicious. If the fail rates were anything like the fear mongers would have it (10% or some nonsense), this would be a headline scandal on 60 Minutes, and not the engine powering Consumer Reports most reliable car of the decade, and there wouldn't be a dozen aftermarket warranty companies out there happy to write you a power train warranty for a tiny fraction of the cost of engine replacement.

Enjoy your car. They all break down sooner or later, these just do it later than most 99% of the time.

 

what weight of 300V 5W40 or 15W50?

I've used the 300V 5W40 and after 10 track hours the UOA was pretty good... the only thing that was low was the actual viscocity...

cSt Viscosity @ 100°C was 10.87 so that was a little low and I don't know the impact of that or if it could go longer in the engine... 10 track hours and 3,100 KILOMETERS

I'm trying DT40 this year from LNEngineering to see how good that is... I have to say though I've been using the Castrol 5W50 which has good UOA's but the Motul 300V had better results.... and Mobil 1 was crap. Don't know how stable Castrol 5W50 is at high temp high rpm but if metal wear is an indicator the Motul was better

 

Funny, tell that to the owner of the 996 that is sitting in my parking lot with an ims failure... We didn't want it to feel lonely, so we parked it next to a boxster with the same problem....

 

Ill update you in a couple days, I should pick it up Friday or Monday, Im expecting it to be in excellent shape though, but you never really know.