Here's an UPDATE:
I was in Tucson (MAN is it HOT there!!) and while there, I replaced the new IAPV I had installed earlier with one of the valves I disassembled and cleaned. The engine ran perfectly all the way home which was a little over 1000 miles. Looks like cleaning the valves is very successful. I plan to run this valve for a while and then I'm thinking of pulling it off and opening the clearances on the piston and the transfer pin a little. I'm betting that will significantly increase the useful life of the valve.
As to what oil I'm using, per CAT's suggestion, I am using either CAT 15W-40 or DelVac 1300 which the CAT dealer tells me is the same as CAT oil.
As for where the contamination comes from, the oil that gets into the valve has no way out so ANY contamination that gets into the valve has no way out. It might be from particles in the oil itself or perhaps, it's wear particles from the valve itself. In any event, the cleaned valve seems to be working perfectly.
Steve
