Although I'm sure it was mentioned somewhere in this thread (which I don't blame you for not reading through the thousands of posts). what happens is the grease seal is only rated for 250F intermittently and it gets hard. The inner lip fails, allowing the engine oil to wash out the grease. What's left of the seal then impedes the free exchange of fresh oil in and out of the IMS bearing. What ends up happening is when the engine is turned off, the oil from the sump ends up filling up the IMS bearing tube. It's that oil that feeds the bearing mostly during operation. So keeping your oil clean and using a quality oil makes a difference, especially using an oil with a higher HTHS vis and something with plenty of ZDDP and moly FMs to reduce wear.

 

Couldn't agree more Charles. And oil technology has changed in the last 20 some years, and why Porsche recommended oils has changed with time as well. Long live the IMSB! Hoorah...

 

Two things stood out clearly when I reverse engineered this: The bearing is over kill in it size and the lubrication plays a minor roll in it's life span(grease or engine oil doesn't matter much). The failures that we know and fear happens in less than 10% of the bearings design life, this is crucial information. Such early failures points to just one thing: Damage to the bearing races. This can happen either at the bearing factory (bad quality control), thru false brinelling (stationary bearing subjected to vibration) or ingestion of debris during operation(causing dents). Some high milage oils contain seal swellers, that could affect the seals and thus letting debris inside.

 

Best post I've read on here in a while.

Bravo.

 

Are you familiar with the term ***** envy? You might want to study it, with all it's ramifications

 

Hi guys,

quick question - is there a way to visually inspect if the IMS retrofit has been carried out on a tiptronic car? Not looking forward to removing both the engine and the gearbox, ordering the kit just to find it was carried out fairly recently. I guess if the oil feed was added, that is fairly obvious, but other than that are there any tell-tale signs? I am asking because I acquired a salvage car and am yet to see it in person. Thanks!

 

This is a long shot but LN usually ask that a removed IMS bearing be sent to them and the new one registered on their web page. I did this with my upgrade in January. I believe the search key is the VIN number.
https://lnengineering.com/ims-lookup.html

 

Thanks, that was a really good idea! No records found based on VIN number though.

 

So I have a 2001 Carrera 4, build date of December 2000. I just purchased the car a month ago with 69k. Put a 1000 miles on it, then got the IMS done.

Few things:

It cost me $3600 including the AOS and a flex disk.

The car had the clutch done at 57k, and the IMS flange changed, but I’m not 100% sure on the bearing itself, however this was 12 years ago.

The bearing that came out had zero play, however, a tiny bit of oil was starting to seep past the seal, so I think that’s what people refer to as stage 1 failure?

In summary, I’m glad it’s done for peace of mind, but I think I would have been ok for quite a bit longer. Also, getting it done isn’t bad, and for those looking to buy, I wouldn’t automatically rule out cars just because the bearing is original

 

I dropped off the car today at Black Forest, a well known Porsche Indy for decades here in San Diego. There were maybe 35 Porsches in the corral, the majority 911s, and no other brands at all. Asked them what they are seeing in IMSB failures these days. They said they regularly replace them, because by now everyone knows it is standard maintenance. But they saw maybe only 2 this past year, where the bearing was ready to let go when they pulled the old one out. They also said that often they are seeing an oil leak as a warning sign that it might be getting weak. If anyone else has updates, we're interested to hear the state of this problem out there.

 

Great shop and also great observation on their part about there being a much better knowledge surrounding this issue.

The biggest issue we see are cars that are years past recommended service intervals for the replacement bearing in their engine and the fact that many shops did not clearly communicate that the IMS bearing is a maintenance item (with exception of the IMS Solution).

The other issue we see on our end is that there are now shops changing IMS bearings that are not Porsche experts or that even have general knowledge about Porsche engines, say something along the lines of a Midas (I kid you not on this). Also there are many shops putting bearings in where the original bearing has already failed because the customer can't afford to fix it right. These cars end up making their way to auction. We've also found cars that have had fraudulent IMS Retrofit serial numbers on them or owners that think the IMS has been replaced, but the IMS flange was actually resealed.

One last segment are shops that believe the IMS is a made up issue and do a clutch and just ignore the IMS bearing completely and have the bearing fail shortly after a clutch change.

It's important to take your car to someone that is knowledgeable and reputable.

 

I’ve had discussions with my local Porsche Shop concerning my IMS Bearing. As you know in 1999’s it is a two part bearing and it has not been a problem, like the IMS single bearing in the 2000-2005 911’s. I would like to hear from those with 1999 911’s and any experience with bearing failure. I have my transmission out and need to replace the pinion bearing. I have a leaking RMS and will replace that and the 3 half casing bolts. 911’s have steel cylinder sleeves and chance of bore scoring is very unlikely. Next week I will pull out the spark plugs and check each cylinder. Fingers crossed.

 

Wow - just wow.

 

If your local Porsche shop told you your 996 has steel sleeves from the factory, they are dead wrong. If the shop also didn't recommend changing the IMS bearing while the transmission was out, they are doing you a disservice. I'd recommend starting at the beginning of this thread and go from there. Everything you need to know is detailed in this IMS discussion thread.

 

Thanks