I am having a problem with oil pressure. After the engine heats up about 15 minutes of driving the oil pressure drops to zero at idle. If I give it gas the oil pressure goes to normal. What could be the problem?

Thank
Rob
1990 Ford F150 v8

 

Is this with the factory gauge or an aftermarket gauge? Sounds to me like your bearings are getting pretty worn.

 

Had very similar problem that got worse till reving wouldn't even work. Pickup tube screen was clogged completely with carbonized crap. Previous owners son used some stop leak junk instead of fixing the rear main seal leak which I did fix. Cleaned screen and pressure returned to normal, however it clogged again after about six months because there was just too much crap in the motor. Just another possibility.

 

If it was me before I did anything rash I'd replace the oil sending unit. I recommend the dealer version over aftermarket. Just a suggestion.