Jake,

if we just would look at a magnetic oil plug - when i change oil it always has some layer of very thin 'paste' of magnetic dust from normal wear, any tracked car will have it. just from a visual perspective - is it possible to tell if ferro-magnetic particles come from IMS assembly specifically?

is it an overall 'safe' approach to assume it is a normal tear/wear as long as you have no 'chunks' or visible specs and all material on the magnet plug resembles thin metal dust? what are the guidelines there? what level of thickness of collected material should be considered a problem?

 

This is known as "ferro-magnetic fuzz" and was the biggest thing that we had to develop the IMSG to not create a false positive when exposed to it. All engines have it, so magnet spacing, type and strength had to be altered to accommodate it, all while being sensitive enough to still trigger an IMS Alert.

Its hard to say where it comes from. Generally the "grey" colored material comes from automotive grey cast iron and thats from lifters and camshafts, generally. Pieces that are shiny can be from hardened IMS wear components like ***** and races, BUT the factory IMS bearing "cage" is also grey in composition and can fool an untrained eye easily.

I know what our engines generate as we see them over and over at different times during development and testing, but thats not universally applicable to all the M series engines. The bigger the pieces the bigger the problem as a general consensus.

Thats a question I could only answer if I were as talented at "spin" as a politician. I won't even try to answer it. When changing the oil post your pics here for others to comment on.

Also, the only magnetic drain plugs that we use are our MCDs from the IMSG and the LN Magnetic drain plug, which is the strongest available. Magnet strength and type will determine the material collected, so a person with a different plug than yours will have different amounts of material than you do, so thats a variable that keeps any blanket statements from occurring. The cheap magnetic drain plugs are less than 1/2 as strong as the 23# rare earth magnet of the LN unit. That makes a difference.

As I had stated before:
Mag drain plug inspection is better than nothing; but since it is entirely possible for an engine to progress threough all 4 stages of IMSB failure in one oil service interval it is simply not enough. The IMSG monitors ferro-magnetic material levels in the oil the entire time the engine is being operated.

 

i use LN unit.

i understand your position - it is difficult to say anything definitive about this. thanks anyway, you are an invaluable resource on this board.

 

Hi, I'm in Vancouver as well and i would like to know who the local LN Engineering rep is. Thanks

 

Hey, I PMed you but your PM is blocked, unblock it and try again.

 

Is this the later, larger size bearing?

 

Yes. Though all your research I'd think you could spot it a mile away by now.