rough idle bad milage weak jakes

[Magard]

Sounds like your falling victim to a mechanic. Oil cooler doesn’t control oil pressure. Could just be wear in the overhead. Are you running gear oil at all. I would suggest a gallon per oil change. I use the Walmart 80/90.

I’m assuming that the oil is changed regularly. Like 10-12k. Otherwise it could e some carbon packing issues.