ims bearing help

[rgzsr]

Would like some help on solution for potential ims bearing problem. Have a 2007 Boxster base with 24k miles.Have no apparent problems with bearing yet, no noises or oil leaks. Ln eng. suggested to just remove seal on exposed side of bearing and let sump oil splash lube bearing. This bearing is non serviceable unless engine dismantled. The other option is tuners D.O.F. kit to pressure lube bearing from port somewhere on head. this option sounds better but I'm concerned about starving passage where oil is to be taken from. Also possible external oil leaks from around ims bearing flange, 60 psi oil pressure will probably be present at high rpms. would be good fix if porsche endorsed this fix.

[Sapientoni]

With those low miles, the IMS probably has many more to go. People have said the engine oil washes the grease out and then the bearing runs dry and fails. NOT TRUE! What happened to the oil that allegedly washes the grease out? Is it not a lubricant? I doubt anybody has caught a bearing that was dry, but still had the seals in place. I am currently working on a 2006 with 72,000 miles that spun a ROD bearing. I'll post the pics of my IMS bearing when I get to that part of the rebuild and everybody can see what it's like.

[steveng1993]

Just drive it and not worry about the bearing that may or may not go.

[tonythetarga]

Originally Posted by Sapientoni

With those low miles, the IMS probably has many more to go. People have said the engine oil washes the grease out and then the bearing runs dry and fails. NOT TRUE! What happened to the oil that allegedly washes the grease out? Is it not a lubricant? I doubt anybody has caught a bearing that was dry, but still had the seals in place. I am currently working on a 2006 with 72,000 miles that spun a ROD bearing. I'll post the pics of my IMS bearing when I get to that part of the rebuild and everybody can see what it's like.

I'd be interested to see what it looks like. I just bought an 06 Cayman S and plan to peel away the seal when I get it home. It would be nice to know a higher mileage non-serviceable type of bearing can have a long run without starting to break down.

[Sapientoni]

Boiler Inspector's 2006 Cayman S had IMS failure at 148,000 miles. I had been praying that was the bearing noise mine had, but no, it was the #1 rod bearing. I bought it at discount knowing it was gonna have a big problem, but hoped it wasn't THIS big.

[mikefocke]

Porsche will never endorse a fix, not in their financial interest. And recall, even if they did, they are the ones that designed the IMS in the first place and got it wrong 3 times.

If I told you there were at least 2 engine parts more probable to fail in your 2007 within the next year than your IMS would you worry? What if I told you the probability of your IMS failing is less than 1/2% in the next year?

You can go broke trying to prevent every cause of failure.

[Scnell Gelb]

RGZR
" I'm concerned about starving passage where oil is to be taken from."
For D.O.F.

1. The pressure drop is 1/2 psi

2. The oil volume is about 300ml/min IIRC.

neither are problematic imho.but use the most appropriate oil. Search "high shear ,anti-foam oil". Current expert(not me!!) best practice benchmarks would be Mobil 1 and Joe Gibbs DT40

The best source of knowledge on DOF is Pedro -search "Technofix DOF" -buy direct from him.He will give you reliable, accurate specs on oil pressure drop and volume.

It is a peace of mind issue not engineering necessity.
As Mike wisely hints, if you really want to worry; search "M96 Modes of failure". The issue is often multiplied by collateral damage.

[Sapientoni]

IMS condition at 72,000 miles. Sorry no pics, but the condition of the IMS bearing was normal, it had a pool of oil in it when I opened the seals. The shaft had about 8 oz of oil in it but it had been sitting up ended in a parts bin for 2 months since disassembly. I am still waiting on the crankshaft to return with #1 rod bearing race repaired.

[Sapientoni]

I found the bearing inner shaft dimension is 1 mm smaller than the inside of the IMS tube. This is for a 2006. I don't know if this close tolerance would be enough to prevent damage if total failure came at high rpm, but for sure, Boiler Inspector limped his another 6 miles home after the horrible noises began upon start up. Would not advise it without a good supply of shamrocks and horse shoes.

[SCUDERIA928]

Better be safe than sorry. I had one engine go due to IMS oil starvation. Another for the IMS.
Get rid of the problem before it happens. Since PORSCHE's water cooled inception I feel that their quality has really diminished. Their metal alloys are junk, crankshafts made out of garbage.
Than you go to certain tuning companies, who "highly" recommend their products, but don't back them up when trouble brews.

[Scnell Gelb]

You did 'pin' the IMS drive gear to the IMS tube didn't you?

[Sapientoni]

The ONLY external preventive action you can take regarding the IMS bearing is to turn the inner bearing stub (the slotted part with the nut holding it to the flange) 180°. This will present a new wearing surface to the balls. The inner bearing race is the smallest (there fore the first) load bearing surface and will begin to fail first. Somewhere on this site is a pic of Boiler Inspector's failed bearing which graphically illustrates this failure.

[thom4782]

Originally Posted by Sapientoni

With those low miles, the IMS probably has many more to go. People have said the engine oil washes the grease out and then the bearing runs dry and fails. NOT TRUE! What happened to the oil that allegedly washes the grease out? Is it not a lubricant? I doubt anybody has caught a bearing that was dry, but still had the seals in place. I am currently working on a 2006 with 72,000 miles that spun a ROD bearing. I'll post the pics of my IMS bearing when I get to that part of the rebuild and everybody can see what it's like.

For lubricating the IMSB, grease only is ok. Oil only is ok too. A grease-oil mixture is not because the combination lubricates poorly.

IMSB fail when the bearing seal has a small leak, oil seeps in and mixes with the grease and the mixture stays there for a long time. The bearing wears during this long period and eventually fails.

If the seal is removed, the oil washes the grease out quickly enough that the bearing wears little.