I have a strange problem with the 292 in my 63 F100. When I start the engine, the oil pressure will initially jump up to about 40 psi but over the next 30 seconds will drop to zero. There is no change in the sound of the engine when it goes to zero like you would expect with no oil pressure and raising the rpms does not bring the pressure up.

Any ideas?

Thanks
Drw

 

did it just start doing this.get an oil pressure gauge and hook it up and see what you have.if it really has no pressure its not long for this world.

 

In my 55 F350 with a 239 I have an oil pressure gauge that was added by the PO because the pressure gauge in the instrument panel did not work. The added gauge goes up to 120lbs. What should the oil pressure be in a 239?

 

45-50 @2000rpm, hot

Cold pressure would be higher. However, 120 psi is excessive.

First, try a known good pressure gauge. If nothing changes, then you probably have a problem with the bypass valve. The bypass valve can be found under the screw next to the oil pickup tube in the pump.

 

Before you start it again in your diagnostic process, check the big gland nut at the pump where the inlet tube from the pan goes in. Use a big adjustable wrench and give it a half turn. There is a little barrel shaped seal back in there that expands and seals as that nut is tightened. Go easy. Half a turn should be plenty.

 

Double post.