IMSB - Did I Dodge A Bullet

[thom4782]

Hi everyone:

This week I replaced the single row OEM IMSB in my 01S with the IMS Solution. The OEM bearing looked like it was brand new. It spun freely and, most important, there was no wobble whatsoever. See the first picture (it looked even better to the eye).

Here's why I'm asking. I removed the seal. The cages looked great and I didn't notice any metal flaking or debris. Also, there was no metal in the filter or the sump. But, because I've never seen the inside of the bearing, I don't know whether the grease had washed out. If I had to guess, I'd say yes.

If my guess is right, my theory is that seals would have limited the amount of oil reaching the ball bearings. As such, it would only be a matter of time before the OEM bearing failed.

What are your thoughts?

Thanks

[Dlirium]

Did you do this IMS work yourself? My buddy and I are looking to replace his clutch in his 99 with 140k miles, and figure we should change the IMS while we are there. He hasn't had a problem, but cheap insurance given he wants to get to 200k at least.

We're just down the road from you!!

[JFP in PA]

Originally Posted by Dlirium

Did you do this IMS work yourself? My buddy and I are looking to replace his clutch in his 99 with 140k miles, and figure we should change the IMS while we are there. He hasn't had a problem, but cheap insurance given he wants to get to 200k at least.

We're just down the road from you!!

I rather doubt it if he has the IMS Solution; that system requires the acquisition of not only the original IMS tool kit, but also a supplemental on kit plus the Faultless installation system, which would put the retail price for parts and tools alone at nearly $2700.

[Jamesp]

My thoughts are the same as yours. The design of the intermediate shaft, a hollow tube sealed at one end (the oil pump drive end), with a bearing at the other can only serve to force a small amount of engine oil through the ball bearing seals washing out the grease every time the engine warms and cools. There's no way the grease can remain in the bearing for very long under those conditions.

[thom4782]

The IMS Solution won't fit a 99. If you're going the low cost route, then either take the risk of getting another 60K on the current bearing or spend the money to put in a dual row LN IMS Retrofit.

[Smallblock454]

Hi,

one point to mention: The normal engine oil level is below the bearing if the car is standing on a leveled ground and the engine is off. It is under oil if the car moves, or not leveled, especially if the car accelerates. In corners the oils swaps to the side of the engine. So the oil level might be below the bearing.

The main problem in my opinion is that the sealing rubber of the bearing loosens plasticizer while the motor gets warm and cold over the years. Old, used oil can enhance this effect. The sealing rubber gets brittle. Oil walks through the rubber and washes out the bearing grease. The bearing gets pitting and fails in the end.

It's good to change engine oil regularly (recommend yearly), because old used oil is much more agressive to rubber sealings.

Regards from germany
Markus

[Gelbster]

The Porsche N.A. recommended oil change at 15,000 miles did not help either !
The by-pass OEM oil filter is an issue.If that is not changed at every oil change .....
Using only 2 scavenge pumps creates oil-starvation in severe brake/decent+turn situations.
The very shallow sump & missing horizontal sump baffle didn't help.
The tendency of a flat 6 to whip up foam in the oil may be an issue made worse by the common use of high detergent oils.
The good news is, there are solutions & remedies for these problems IF you read the Forums diligently and ignore the nonsense.
Others with superior knowledge and experience will certainly be able to improve/correct on this list.

[Perfectlap]

Originally Posted by Gelbster

The Porsche N.A. recommended oil change at 15,000 miles did not help either !

Does anyone know if Porsche are making a specific recommendation on oil change mileage for m96 engines?

[KRAM36]

I think it looks perfectly fine. How many miles were on that bearing?

[Porsche9]

Besides the grease missing it looks fine. My was similar to your, grease missing due to the seal failing but no loose metal of any sort in the bearing, filter or sump.

[KRAM36]

The grease looks fine. If you had oil getting into it, the grease would look gray.

[Smallblock454]

Hi,

the bearing looks pretty well. No visible cause to change.

If the sealings fails it has cracks, or peaces miss in general the grease is gone after a very short time. Also you'll get pitting on the bearing balls after a very short time.

The recommended oil change interval in germany is every 20.000 Km, which is around 12.500 miles. Oil change always means oil filter change too.

In germany a yearly inspection for the car is recommended by Porsche. In general Porsche does a oil and filter change if you'll bring your car in for a yearly inspection. Most poeple haven't done that, because that did make the car very expensive. Porsche charged around 28 euro per litre in 2006.

I don't know if regular oil/filter changes are the solution. There are also other factors like the quality of the seal bearing, over revving of the engine, the overall construction of the engine casing… also daily driven cars seem to have less IMS beering fails…

I'll do a yearly inspection and oil/filter change myself. By only driving around 4.000 Km (around 2.500 miles) a year the oil in my car definetely can't be the cause for an IMS fail. But i have to say that in the first 5 years i did only inspections / oil and oil filter changes every 20.000 Km.

Regards from germany
Markus

[thom4782]

The bearing had 125,000 miles on it.

The car is a daily driver. Oil and oil filter were changed faithfully every 5000 miles.

[KRAM36]

Originally Posted by thom4782

The bearing had 125,000 miles on it.

The car is a daily driver. Oil and oil filter were changed faithfully every 5000 miles.

Nice! Mine has 116k miles on it and it's a DD too. I change my oil every 5k miles too since I've had it.

What oil did you use?

[Jake Raby]

Incorrect. The Faultless Tool is NOT required for the IMS Solution installation. The tool is only required for the Single Row Pro retrofit.

When the IMSB was removed, was any engine oil released from the tube?

[JFP in PA]

Originally Posted by Jake Raby

Incorrect. The Faultless Tool is NOT required for the IMS Solution installation. The tool is only required for the Single Row Pro retrofit.

I stand corrected.............

[Tarek307]

Forget the IMS, my engine just pretty much got destroyed because of the camshaft/lifters

"The piece of cam cover was ejected after the lifter failed and was shot through the cam cover."

i guess this is another very common problem with them...makes me now agree they are POSs , mine had RMS & IMS done before

[thom4782]

Jake - there was oil in the IMS tube.

[Smallblock454]

Originally Posted by Tarek307

Forget the IMS, my engine just pretty much got destroyed because of the camshaft/lifters

"The piece of cam cover was ejected after the lifter failed and was shot through the cam cover."

i guess this is another very common problem with them...makes me now agree they are POSs , mine had RMS & IMS done before

This can be caused by a broken slide rail. If the part comes between chain and chain wheel and is big enough and is not crunched the engine housing can burst. In general this is not a common problem with 986/996 engines, but we had this problem over here in germany 2 times.

Earlier 944/968 englines have broken chain rails as a common problem. But maybe it can be a 986/996 problem in the future. The plastic of the slide rails will not last forever and they definetely will get worn.

[Giller]

Originally Posted by Tarek307

Forget the IMS, my engine just pretty much got destroyed because of the camshaft/lifters

"The piece of cam cover was ejected after the lifter failed and was shot through the cam cover."

i guess this is another very common problem with them...makes me now agree they are POSs , mine had RMS & IMS done before

They definitely aren't POSs. The plastic rails will deteriorate over time (like most parts) and need to be checked now and again. Keep an eye out during oil changes - not unlike the ims - but instead of metal, you may see little bits of plastic. If this continues, take a close look at the rails.
But certainly not "a common problem".