Tried synthetic oil in my old 7.3 and ate a main bearing in two weeks

I always swore by Rotella 15W-40 conventional in my 2001 F-350 with 280k on it. Got talked into trying a full synthetic by a buddy who runs a fleet shop in Tulsa. Two weeks later I had a knock that turned into a hole through the oil pan. The shop that rebuilt it said the synthetic cleaned out 20 years of sludge deposits all at once and plugged the oil pickup. I learned the hard way that old engines sometimes need that buildup to keep running. Has anyone else had a high mileage engine die after switching oil types?

2 comments

2 Comments

ericjackson1d ago

Killed my 6.0 doing the same exact thing, that sludge was holding it together.

phoenix8451d ago

Stick with Rotella 15w-40 conventional on old high-mileage 7.3s, don't risk switching.