I'm sure it's dirty. 5.7 with over 100,000 miles and I haven't checked idle or engine hours, but for sure very high. Not the best maintenance here. It just came out of fleet for lower rad hose and I think they did oil change while there.
AH HA! Ok, I was waiting for one of these to rear its ugly head-- this will not work on an MDS engine unfortunately, 99% of the time thats just a down right failed lifter usually taking a camshaft with it.
And not to start any kind of tinkle match, but I've ram trans fluid and MMO in oil for the duration of the life of said oil until its next change.
