1995 Ford F150. In park, pressure gauge reads normal. Can rev the engine up - stays normal. Put into gear and up to about 25 MPH, the gauge reads normal. Once we get above 25 MPH, the pressure gauge drops to zero. Oil level is fine.

Any ideas?

 

The stock gauges suck in these trucks. Get a set of aftermarket gauges. Its a good investment.

How many miles are on truck? Any knocking or strange noises when gauge drops?

 

79,000 miles on the truck. No knocking at all. Engine sounds good and strong.

 

I would say its the sending unit for the gauge then. Get you an aftermarket oil pressure gauge and forget about the stock gauge. My oil pressure gauge reads low even when my aftermarket gauge is reading 65psi..