My 93 trooper has oil leak, I know and think it was minor until I had a shop work on it. Before the work, the botom of the enginewas messy but no oil drips to th ground. Then one day I asked for a good garage to a friend, and he told me the shop. I did not fully believe it and asked to a co-worker, who also think that was a good shop. "They never fail me",that's he said. So I havee the shop check the truck and they said it needed a new valve cover gasket. I have them done it, but after two days I saw worse leak. Oil drips to the ground where I parked. I also noticed vapor smelling oil when I waiting at traffic lights. I have them run a check a again, they said it was leaking from thr oil pan and the valve cover was ok. This time I did not believe them because I saw oil all around the starter, which is higher than the oil pan. They then blame the rear main seal. Is there a way to diagnose whether the oil is from the rear main or the rear valve cover gasket?
Thanks