IMSB - Did I Dodge A Bullet

[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.

[Jake Raby]

Originally Posted by thom4782

Jake - there was oil in the IMS tub

e.

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

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

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.

[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".

[tonichristi]

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

[thom4782]

Originally Posted by tonichristi

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.

[Jamesp]

Originally Posted by tonichristi

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

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.

[flaps10]

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 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.

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.

[Jamesp]

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.

[Smallblock454]

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.

[Smallblock454]

@ Jamesp.

Thank's for explanation. That makes sense.

So maybe the cars that were allways parked with the front downhill didn't suffer as much from the IMS bearing problem.



Whereas this car would have big problems - if it would be a 986.



Thanks again and regards from germany
Markus

[Gelbster]

I thought of getting a groove milled in my LN hardened+shot-peened oil pump drive. Then use a good quality 6204 bearing with the appropriate seal mods. But I if I did, I would never be able to look Jake in the eye again. :chicken:
But seriously, thanks for some great comments. I had abandoned any interest in IMSB threads because they usually are just repetitive 7 argumentative -but this is interesting.