IMS Bearing

[Roger duRand]

Talk to Jake, at low RPM's their is a load on the bearing. At high RPM almost no load at all. So run the car RPM's in the mid to upper limits. The factory bearing is at design limits around 90 miles. The newer bearing made by Timken will last forever. Go to Flatsix website if you want the complete info. :clapping: My 911 will get the mod this spring. E

Falcon-- What do you mean 'design limits around 90 miles'?

[pk2]

Roger 2x.

Falcon what gear? what rpms? wouldn't a load calculation of some sort be in order thats translatable to normal driving be helpful? Is it a question of load or rpms?

Regards, PK

[jmatta]

My 3.2 S is going on eight years old and shows 17k miles. To date, I have installed the LN billet oil filter adapter/magnetic drain plug and the 160 degree t-stat with new OEM coolant. My car is not a daily driver, so when it is driven, it is driven for a long enough period to get it good and hot and use the upper ranges of the revs. I've always used 5W or 10W40 good quality synthetic (not M1) and change at least yearly, which is less than 3000 miles. My car does not need a clutch, but I am still considering updating to the LNE IMS bearing, so my engine doesn't become a boat anchor at some point in time. I feel it is just prudent to do so, as a 3.6 rebuild is not in the cards at the moment with two kids in college.

Edited December 30, 2009 by jmatta

[txhokie4life]

Rodger,

I was real nervous about these issues some time ago. The conclusions I came away with were;

1) *** peter said, the more milers you have, the less likely it is to be a problem. (and I was feeling so lucky to only have 35k) Apparently the magic number is around 40k. There are few broken hearts after that.

2) It would seems to have little to do whatsoever how you drive it, warm it up, etc. Happens to the nicest, caring & most consensus people in the world.

3) There is no hard data, only anecdotal. People have had to run poles and the like over the years but there’s no really accurate way to run a decent study. Porsche keeps a very tight lock on what must be the best evidence.

Regards, PK

Well those pics of the old vs new IMS was due to me dropping in a 55K miles 2.5L in a

92K mile 2.5L that had an IMS failure.

So YMMV, but I've seen up close and personal a 92K mile failure.

Mike

Mike--

Sincere condolences!

Just curious: what were the conditions at failure? Hard to believe the anecdotes of it occuring at idle!

RdR

I do not know -- I bought it for next to nothing knowing the engine was shot.

when we put it on jack stands the IMS bolt was looking us straight in the eye -- wedged

perpendicular in between the flywheel and engine case.

Mike

[infocusf8]

I bought my '99 Boxster with 74K miles on it and use it as a DD and AX and track it. The last time I was in for service work a small amount of oil was on the bottom of the case. Although the car does not burn or leak oil, to the point of drops on the ground under it, I've decided to do an RMS replacement and install the LN IMS bearing while the Tiptronic tranny is out. I'm having it done at Flintworks in Campbell, CA on March 6th and will be taking photos and possibly a video of the procedure that will be posted on the Babblers web site. At this point I'd rather spend $1800 for the whole procedure then have to shell out $10-15K for a new motor. I realize there are other reasons for engine failure but the IMS bearing seems to be the most prevalent. Thinking that your motor is safe after a certain number of miles is not conclusive as the last person I know who's IMS failed had it happen at 120K miles as he was pulling into his garage.

[mikefocke]

All 986/987 M96 engines of every year can experience failures of the IMS bearing. At any mileage. With any version of the Porsche bearing. I am aware of several at 100K miles plus. With any service interval (though more frequent oil changes are better). With any oil (though better oils are better). I don't recall Charles or Jake saying that the lower the temperature the less probability, and that goes against the higher revs theory.

My personal suspicion is that the "see less on cars that are driven hard or raced" observation is probably because such people are more conscious of the maintenance of their cars and change the oil more frequently. So that, if the inner IMS bearing seal fails and allows oil in, it is clean oil and not dirty. Clean oil displaces the grease and allows lubrication without the wear that dirty oil would allow. And since the oil to the IMS would be via splash and not pump delivery, the more vigorous the occasional splash the more oil gets through the edges of the disintegrating inner seal.

I presume you all are aware that Porsche has shortened the oil change interval on all Boxsters to 12k miles from the 15k they suggested for the early models. Think just maybe they were seeing oil related failures? Unless it is all highway miles, do the change even more frequently than that...oil is cheap compared to a new engine. (And if you want to save some money, don't change the filter but every other 3k-5k change. Just do the oil as that gets some 90%+ of the effect for less work and cost.)

[pk2]

Mikes right. Anecdotal evedence statistically just means very little. If we were around here 10 yrs ago we would be talking about IMS failures on cars with 10,20, 30k on them. I to don't quite buy the " drive like a deamond" theroy. There is just isn't anything ressembling a controlled study to come up with any statisticaly meanigfull conclusions about this issue.

Regards, PK

[txhokie4life]

Just looked at an 00 S with 109K miles -- 90% confident it just had an IMS let go.

Seller described it as: - -sounded somewhere between marbles and metal slapping,

but the (bite my tongue) - guy - drove it anyways.

He bought it untested from an auction -- decided to test drive it when it reached his lot,

made it 1/2 mile away --- than towed it back to his chop shop/lot. Put it on CL listed

it as DOA (fortunately). But his price was too high.

The codes were all misfires, cam sensors, and a few others.

Oil all over over the engine/transmission gap area.

BTW, -- I think the <bite my tongue again> is going to take it back to Auction

and try to resell it -- It was in decent shape otherwise.

So if you are in Austin and there is a Black 2000 S at auction -- Be weary engine is likely toast.

Mike

Edited March 1, 2010 by txhokie4life