I live in NJ and drive a Forester XT (2.5L turbo with 12k miles). I took a trip to SC in July running M1 5W30.
While in SC, there were a few days of temps in the upper 90's. One day the ambient temp hit 100F. That afternoon, I went to start the car after it had been sitting for two days and heard an awful knocking like the engine was completely dry. Sounded much worse than the normal valve tap some Subies are known for.
I check the oil regularly (about three times on that trip) and the oil level was fine. The engine hasn't done that before, and hasn't done it again since. Temps dropped back down to the lower 90's that week. The temp chart in the owner's manual shows that 5W can be used for up to around 100-104F. Is there a chance that most of the oil drained back into the pan since it's thin? Anyone think that a 10W would have done the same
Comments appreciated.
-Dennis