IMSB - Did I Dodge A Bullet
 

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

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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.

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.

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.

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

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.

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

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

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.

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

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

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?

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?

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

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

Jake - there was oil in the IMS tube.

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.

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".

I bought a 1997 Boxster and immediately installed this:https://vimeo.com/89968767
It is way less expensive and
more cost effective and I have not had the first problem.

Youch! the groove cut down the side of the key at the highest stress concentration screams, "break me!", and where does the punched out piece from the solid end of the IMS go? Through the new bearing if it's not retrieved. The concept is outstanding, but the execution leaves me cold.

Just realized, "BobRickel" is posting the same video on other IMS strings. Wonder if there's a sales pitch buried in there somewhere...

In other words, James didn't choose this fix, so it must be wrong.

1) A hole punch doesn't actually punch out a slug of material, but deforms the metal to stretch out a hole.
2) The slot is parallel to the torsional forces exerted on the shaft, therefore not likely to promote failure. Were it perpendicular to the exerted force, then you should worry.

Let me guess: you like the LNE fix, so anything else is inferior and wrong? Yeah ;)

No one has ever proven with quantifiable facts that LNE bearings deteriorate from inadequate lubrication. No one to my knowledge has ever put any verifiable facts on the table to prove their 'forced' lubrication approaches last measurably longer than LNE bearings in real world applications. So it doesn't matter what one believes. It's all just marketing puffery until someone puts serious money on the table in terms of a warranty to back up their claims.

BTW: I choose the IMS Solution for two reasons. LNE has a great, implicitly verifiable, track record in selling IMS fixes that either don't fail (double row retrofit) or fail far less than the OEM design (single row retrofit). More importantly, my gut instinct caused me to believe that the plain bearing Solution will reduce the likelihood of catastrophic engine failure should the bearing itself degrade. Admittedly, I don't have any facts to back up my gut instinct, but that was my risk calculus. So I chose it.

Then you were at Stage II bearing failure, at least. Period.


Attend my class and you'll learn all about this. See that broken factory oil pump drive key? That cost me 25K back in 2009, I'd never even consider milling a pathway down the edge of one of these units. All that does is create one continuous, longitudinal, stress riser. I also have another pic that I won't post in public, at least not yet.

Punching a hole in the center of the aluminum end plug within the IMS shaft also compromises the press fit of this component. Anyone who has seen mode of failure #8, (where the aluminum plug dislodges and allows the oil pump drive to fall into the IMS tube during operation) would also never consider doing this.

Well, i have to agree with Jake. The milled pathway is not a ingenious highlight. Especially if they use the original part and mill it. But the idea isn't bad at all. It's more how they execute it.

The problem i have with all that solutions is that there a a lot of clever ideas. But there isn't time and money to do material tests and long term tests. So at the end of the day you have to choose the solution that seems to be most convincing for yourself.

You're clearly not an engineer, and don't follow this forum too closely. Removing material from the outside of a shaft is the absolute worst place to take it. Not only will it weaken the shaft but worse it will promote cracking. A hole down the axis will have negligible effect on the shaft torsional strength. I independently came up with this oiling scheme and posted it to this forum perhaps 18 months ago complete with power point sketches. I did not go with LN in my engine, but vented the IMS shaft to eliminate pressure across the IMS bearing to prevent engine oil being forced through the IMSB and washing out the grease. How do you think the oil always ends up inside the shaft? There is only one path, and only one substantial motive force to put it there.

I've installed this product in my engine. The groove is only 0.005" deep and the shaft they supply is definitely forged. I drilled the hole since my shaft was on the bench. No way in hell was I going to use a punch.

No one has to prove their product is superior to the LN product. They only have to show that it's better than the POS the factory put in. That's going to be pretty easy.

EPS does in fact warrant their bearing for five years. That said, that is a warranty on the bearing only (same as the LN warranty). It would be insanity to expect a manufacturer to warrant your entire engine/driving experience on a bearing that leaves their facility and installed by someone else. Not ever going to happen.

I've mentioned elsewhere that EPS are not idiots. If you have a Cayenne, Q7, Touareg you will eventually come to know their product for your center shaft bearing. It is a more elegant and far cheaper fix than the factory design.

Well, to be straight up about it, this idea relies on unfiltered oil which directs any particulate contamination directly through the roller bearing. This is why I didn't pursue it on my engine after I thought of it, even with a ball bearing. Particulate contamination is a major cause of cascading bearing failure which is why its not uncommon to see a certian organization request their products not be used in IMS failure recovery cases. With this setup I'd definitely run a better filter than stock and neodymium magnets on the filter and on the oil pan particularly under the oil pickup.

I have no interest, financial or otherwise, in the EPS IMS solution except to share a great product with others on this forum. I have owned/restored 429 vehicles (311 cars/trucks and 118 motorcycles), including 23 Porsches over the last 46 years and know a good product and engineering when I see it.

Nice numbers Bob. I'm super impressed. Did you know this great product ran unfiltered oil through a roller bearing? Is that how you'd treat the engines in your 4000+ vehicles? Well that's not how I roll, or any car company since the 1920's. Rock on Bob! :cheers:

"Unfiltered" is slightly misleading. We're not talking about "never been filtered nasty, metal filled oil", it's oil fresh off the oil pump, immediately before the oil would have been rammed through the filter.

That would make it the same as the splash oil supply used on any other option but the Solution which isn't available to all of us.

One could argue that the LN Solution uses "uncooled" oil since it takes the oil from the filter base but prior to going through the cooler (the next step in the oil path). That would be an unfair claim.

I'd say in both cases the oil is being filtered and cooled several times per minute.

And yes, I have the LN filter and magnetic drain plug ready to install.

Hmm.... unfiltered, or "fresh off the oil pump, immediately before (my bold) the oil would have been rammed through the filter". Hmm... before the oil goes through the filter... seems to me that would be the very definition of unfiltered. And I am talking about nasty metal filled oil, there will be wear particles in all engine oil, that would be what the filter is for... I totally agree about the "same splash oil used in any other option". That's why I didn't go with those. Particulate in a mechanical bearing = failure. Best to keep the bearing sealed, and the grease in the bearing.

I worded it carefully enough that I felt like I acknowledged where the oil came from. Not trying to get into an argument James, I totally respect your input on anything I've seen here.

My point is that in a normal running engine there should be zero loose metal. Since it would seem that most wayward metal in the M96 comes from the stock IMS the last place I'm worried about pumping metal through is an already failing bearing.

Once any metal starts coming off that bearing the s*** show has begun, and the place I'd LOVE to see protected from loose metal would be the mains and rod bearings, and the LN full flow oil filter does that far better than the stock system.

Those main and rod bearings required more than a little wrench turning for me to hold in my hands.

Flaps10 (and I have to say I love your handle, being an aircraft engineer - not aerospace mind you despite the fact my disposition is manned spacecraft) don't tread lightly, and please argue. I'm an engineer, not a politician. I respect your opinion though I might not agree with it at first, I have to be convinced. I've had my engine down to the crank and back up again, complete with my own internal IMS modifications. I can confidently say I own the one and only M96-24 with a vented IMS. You chose a bearing lubrication path that I not only came up with first (to my knowledge) but also discounted due to using unfiltered oil in the lubrication system. Particulate (even very small) will damage the surface finish of bearings. As the surfaces are damaged, they begin to damage themselves (brinelling) then it's a quick trip to failure. Roller bearings having line versus ball bearing point contact appear even more susceptible to this damage. That's why I suggested the magnets - they are effective in pulling out very small particles of metal from the oil. My sense is that the configuration you chose should be fine in the long term, but if it were me I'd be sensitive to precluding particulate in the oil - hence the suggestion for magnets.

This whole 'forced oiling' debate is hilarious.

Without any measurable facts put on the table, e.g., forced oiling increases lubricating film thicknesses by X percent and reduces bearing wear rates by Y percent compared to splash oiling, it's like arguing whether person gets wetter jumping in one of the great lakes versus jumping in a swimming pool.

Vented sounds interesting.

If you consider that the IMS is a sealed tube, and that the air gas volume inside is constant, you'll have a very different air overpressure at let's say 10 degrees celsius and 110 degrees celsius. At the same time you'll have a constant underpressure of around −2 mbar in the engine. Does anybody know the inner volume of the IMS tube, so we can calculate the air overpressure at different engine temeratures?

This might also be a cause why the OEM IMS sealing is stressed by temperature change.

The term vented is used as ventilation i think. How does that work? Because if you do not use a sealed bearing the pressure in the engine should be the same as in the complete engine. Or am i wrong?

PS: sorry that i use the metric system.

You've got the point. I made this video a year ago

https://www.youtube.com/watch?v=qzHwWUgU37k

There are 7 short ( 2 minutes or so) videos detailing precisely what you are saying, and showing how I approached this problem. I'm at just about 3000 miles since I made this simple modification to the IMS and all is well. I redline just about every day because it is fun. Click on my name under the video if your interested in seeing what I did. There's been an implication that Porsche blew the bearing design by overloading it. I have a hard time buying that unless the mistake was assuming grease in the bearing instead of oil when doing the load calcs. That is part of the reason I went back with a sealed high temp (high temp grease and Viton seals) greased deep groove steel ball bearing with a vented IMS. The other reason is that the fully sealed bearing feature coupled with venting keeps any trash in the oil out of my IMSB.

They made sure to leave the "Made in Germany" clear on those "drives". There's more to that story.