With our cars, they started replacing the whole engine and shipping the old one back to FCA for analysis. A zone specialist challenged our maintenance schedule and said we needed to change oil every 3,000. I said "we already do that". Then he came back to me and said we need to change it every "??" hours instead, because of idle time. When I calculated the amount of hours our cars went between changes, it was less than what he was recommending.
I've always suspected idle time being the problem but wasn't sure WHY the idling could cause the problem, other than possibly low oil pressure. I think Tony had some very valid points that show what problems would exist especially during idle.
