IMS Excellence Article
 

Hi All, I've read the latest article about a procedure to check for a potential IMS issue. It involves taking a part the oil filter and looking for patricles. My question is, how accurate is this method from preventing a IMS disaster?

Is there always increased engine wear (exalpining the particales in the filter) before the IMS completey fails?



Thanks

No. it is metal bits from the IMS bearing as it begins to fail...............

Thanks JFP. That makes sense. It's good to know there is something we can do to warn us the IMS may be failing.

I hate to sound like a broken record but I wouldn't wait to do this upgrade. Most experienced Porsche specialists could do it in a day. Two hours to drop the trans, two hours to installe the new bearing, check some things etc and put it all back together. Waiting for the clutch to wear out seems a little crazy to me in retrospect.
In order to save yourself $600 in labor your going to roll the dice on an engine replacement that will cost over $10K? I'd rather pay the labor to take down the tranny twice and consider it a insurance policy of sorts.

I'm sure JFP will correct me if I'm wrong, but metal bits in the oil filter don't necessarily mean the IMS bearing is failing. The metal could be coming from other places instead. None of which is good. :rolleyes:

The "trick" is what kind of metal you find. There are lots of light alloy sources in the M96 (block, heads, pistons, bearing shells, etc.), but only a limited number of ferrous sources; these include the crank, piston rings, valves & springs, the cams and followers, cam chains, the oil pump, and of course the IMS bearing. If you were to find any significant amount of ferrous debris in the oil filter (stuff you can pick up with a magnet), I would seriously consider taking the car out of service until you can determine the source; to do otherwise is to invite disaster…………..

Recall that the IMS
 

is sealed from the crankcase and the engine oil by an inner seal. So I would assume it is relatively hard for large bits of the bearing itself to get out until the inner seal is really gone. The idea of the seal is to prevent a hot film of oil from getting to the bearing. So the fitment is designed to be pretty tight. Now it doesn't always work out that way and we all have seen pictures of where oil has intruded.

I only bring this up to support the postings that bits in the oil filter can be from many sources.

Mike, by the time the bearing starts to shed metal bits, it usually has already tore up the seal because of the shards and because it has begun to "wobble" off axis a bit due to internal wear/degradation. .

I agree with "JFP in PA" and have the experience with this engine to back that up. I JUST split a Boxster block with a bad IMS (center of bearing came out by hand). I decided to split the block to have it tanked so there was a guarentee of not getting metal in my bearings later. I took the IMS in to my local machine shop to have the old IMS bearing race taken out so I could replace it. When the machine shop tried to remove the bearing they found that the main IMS sproket had started to separate from the IM Shaft. When I got there I was able to break it off by hand. Imagine the disastrous effects of that if I had just replaced the bearing with an LN bearing and not dug any deeper! What happens is as the IM Shaft starts to spin out of its proper place that puts stress on the main sprocket. The main sprocket is spot welded on and not build the withstand side-to-side stresses. In a very short amount of time the side-to-side stresses weaken the spot welds and thats it! Game over. LN Engineering states at the bottom of there IMS page (http://www.lnengineering.com/ims.html) that if your bearing has got to the point of coming apart that you should sent it for the IMS Upgrade instead of an IMS retrofit. Now that I have seen the reasoning behind this I FULLY AGREE.
In short, if you have chunks of metal in your oil filter and your IMS bearing looks like the picture I have posted, DO NOT JUST REPLACE YOUR IMS BEARING!!