Stock oil cooler is in place. This issue has been going on for a couple oil changes, I've seen no evidence of metal contamination in the oil filter.

Thanks folks. A UOA may be happening, and I'm lucky enough to have someone local to me with 35+ years experience with Mercedes diesels. His name is Jan and I thought it completely appropriate that he has a very thick German accent. As soon as I have time I'll be dropping it off, but for now I kind of need to keep it around and mobile until I get the GTO rolling again.

As an aside, anyone have an '04 GTO differential for sale?

Too many irons in the fire!

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap