My water pump recently went out, the engine got pretty hot (not hot enough to blow head gaskets or anything) but when the engine got hot the oil pressure dropped to the red when ever I gave it gas. Now the water pump has been replaced, I have very good oil pressure (even with high RPMs) as long as the engine is cool. When the engine warms up enough and the RPMs raise the oil pressure plummits. I know that heat will thin the oil, what I’m wondering is when the engine got so hot could it have permanently thinned the oil? Should I change the oil? Or am I looking at replacing the oil pump? I really don’t want to replace the oil pump if I don’t have to, it’s in the oil pan and I have to raise the engine to remove the oil pan.
’93 Ford F150
5.0L (302) V8