Using Durametric to Detect IMS Bearing Weakness

[mikefocke]

Keep in mind that the bearing/race contact area starts to get rough when the lubrication breaks down and the first particle is shed. The wear then accelerates.

So depending on a check of the oil filter media, a magnetic drain plug, or a deviation check is no sure thing because you aren't going to do any at a frequent enough interval to catch the problem with any probability before it is spraying significant debris into the oil passages and or taking out the sprocket/chain interface leading to valve clash.

Sure you can get lucky and catch it but the probability is against it.

[Jager]

Just to add to my previous post... My old IMS bearing was not falling apart but close inspection there was a little movement between the inner race and outer as shown in the picture. This bearing might have gone another 200k miles... Who knows?

[jaykay]

Yes, I replaced mine with a retro-dual row. My bearing(s) were in great condition but there was another guy in that day that was not so lucky.....just on the verge of disintegration. He was faced with a long process of monitoring oil and oil changes to try and catch any debris.

I would like to monitor the health of the new bearing as well as tensioners. I figure that my oil change intervals would be suitable

[ChairmanRon]

I am running the diagnostic now, comparing Cam Deviation 1 and 2. They do NOT change while the engine is idling. Cam Deviation 1 stays at 0.64, and deviation 2 stays at 0.66.

See pic below.

Since the deviations are within the norm and do NOT change, does this mean we do not have a problem indicator with this test right now?