IMS bearing failure

[M. Murphy]

I have read forums and watched videos ( including Pedro's ) on how the failure occurs. Because it seems air and oil are trapped in the hollow shaft and end up contaminating the IMS bearing lubricant I wonder if anyone has considered drilling several small (.050) holes in the shaft. I realize this would have to be done coinincidental with an engine teardown. This would allow release of any oil captured and equalization of air pressure. If it were possible to try this and if it resulted in the bearing lube not being comprimised doesn't it make sense that the bearing life would be greatly increased?

[GTBrandon]

Isn’t part of the issue that the ball bearing lets oil in which therefore ruins the lifetime grease lubricating the balls. So drilling holes would only speed up the failure if I’m not mistaken.

[M. Murphy]

If I understand correctly the air in the shaft/tube heats and cools expanding and contracting. The oil migrates through the bearing seals, some becoming trapped in the tube and becomes rancid then acidic. The acidic compound then gets into the bearing causing damage. To me it seems small vent holes would allow equalization of air pressure and allow oil to leave the tube.

[GTBrandon]

Ahh drill holes in the shaft, wouldn’t that let oil from the engine case into the otherwise sealed shaft?

[M. Murphy]

And allow it out again.

[JFP in PA]

Drilling holes in the shaft is a bad idea on several levels, primarily for strength reasons as the shaft is thin sheet metal; plus IMS Solution equipped cars actually put a plug in the shaft to seal it up, which goes 180 degrees against your logic. It is actually better to keep oil out of the shaft in the first place, again for multiple reasons....

[feeshta]

Wrong thread somehow. Oops

[M. Murphy]

I asked this question in the spirit of " the only stupid question is the one not asked". My impression, probably from Pedro was that the major failure element was the sealing of the tube and resulting pressure differential. Although I have not actually handled a tube my impression from the videos was that it is not delicate or fragile. Oh well.

[JFP in PA]

Originally Posted by M. Murphy

I asked this question in the spirit of " the only stupid question is the one not asked". My impression, probably from Pedro was that the major failure element was the sealing of the tube and resulting pressure differential. Although I have not actually handled a tube my impression from the videos was that it is not delicate or fragile. Oh well.

The IMS shaft can actually collapse and fold over on itself during an IMS failure; sturdy it ain’t. Pedro has said a lot of things that I cannot agree with, like it isn’t the bearing, it is the lack of lubrication; well if that was the case, dual rows should fail more often than single rows, which is not the case either.

[mikefocke]

One man's way of looking at the IMS issue.

Oil getting into the bearing is not the problem, it is how much and how clean and how much of its lubrication qualities get used up while inside the bearing.

Many replacement IMS bearings are designed to be lubricated with a combination of immersion in the crankcase oil when starting and with the oil mist that occurs naturally within the crankcase when running. They run for many tens of thousands of miles that way. There is a shop in the UK that removes the seal thus permitting the oil to deliberately wash out that "permanent" grease and they run the original bearings.

The problem with oil getting into the bearings may be that the seals, being partially still intact, don't allow a sufficient amount of grease and oil to get out and thus any contaminants sit there in oil whose lubricating properties have been compromised by time and temperature and overuse and chew at the balls and races. Remove the seal and the oil flow more freely and gets exchanged with cooler oil and potentially the nice clean oil you just put into the crankcase.

Even better is no seal and a better bearing. Porsche underspeced the original bearing characteristics and private suppliers have done a lot of multi-year investigations into better designs with better materials. Tens of thousands of bearings have now been swapped for better designs.

Perhaps best but expensive is a completely different bearing type with a filtered oil feed.

Here is a good starting point for reading.

[flmont]

I wonder how many of these kits have been used,2 K on a 8-10 K car Hmm..but will it truly fix it for ever,..so to speak

[cnavarro]

Originally Posted by flmont

I wonder how many of these kits have been used,2 K on a 8-10 K car Hmm..but will it truly fix it for ever,..so to speak

There have been over 30k Retrofits sold in the last 10+ years and somewhere north of 3k Solutions in the last 6 years.

Retrofits were never intended to be a permanent fix - it's a service item in our honest opinion.

As far as the IMS Solution, we've seen enough solutions back for inspection after an engine suffered a scored bore or some other failure that we know it's bulletproof and will certainly last the life of the engine, let alone the torture testing we put it through during development.

In most cases, the Solution holds up with no damage and has gotten reused during the rebuild of the engine for what it's worth!

[flmont]

Yea,..I think its worth the money for a permanent as long as its documented it sure seems as tho it is...

[mikefocke]

Any preventative maintenance done is a bet that the results will be worth the cost over time. Expensive maintenance is a bet that you don't have an engine failure from another cause. You don't crash the car totaling it. You don't get tired of the car and sell it (though the IMS issue is well known enough that having it done will help the resell time though total cost recovery is doubtful at the low end).

Ask yourself why you are choosing this bit of preventative maintenance as opposed to spending the same amount of money on another form of maintenance. If you are doing it to sleep better at night because of the well known nature of this issue, that could be good enough reason for you.

[flmont]

Yes sir, Thanks..!!

[pa30crewchief]

Replaced IMS bearing at 98000 miles on a 2000 911 Cabrio Tiptronic. I used the Pelican Parts kit as its the cheapest option and I am not seeking infinite life from this engine.

The old IMS bearing was fine. I honestly don't know if I have any more peace of mind as who knows if this new bearing will grenade in 5000 miles?

I changed the IMS flange to the new style with two rows of O-ring instead of one row of O-ring to eliminate a persistent oil seep.

Other service items at 98000 miles were replacing the Air Oil Separator, the oil cooler, all the idler wheels, the Rear Main Seal (showing signs of seep) and Front Main Seal. Misting of oil where the AOS return pipe enters above cylinder 4 so will replace that little valve as well. Inlet manifold and injectors cleaned.

Hopefully this engine will get another 50000 miles or so.

[BYprodriver]

Originally Posted by M. Murphy

I asked this question in the spirit of " the only stupid question is the one not asked". My impression, probably from Pedro was that the major failure element was the sealing of the tube and resulting pressure differential. Although I have not actually handled a tube my impression from the videos was that it is not delicate or fragile. Oh well.

There are no questions that have not been asked & answered about the IMS & IMSB.

Search the answers are out there...

[M. Murphy]

Wow, I guess I've been told.

[Bilmar72]

For me peace of mind for my mint 2004 S (65,000K) came in the form of the IMS Solution from LN Engineering. I like the idea of an oil fed plain bearing, being simple, reliable and even if worn should not destroy the engine. The tool kits and IMS Solution kit were purchased from Pelican parts and I found the quality of every component was first class, the packaging was superb and the instructions which came with the new bearing detailed and complete. The original bearing, a single row, was worn at on with chatter marks in the outer race. Car still running brilliantly.

[azbanks]

https://www.pca.org/news/2017-11-21/pca-spotlight-intermediate-shaft-and-ims-bearing-explained