Sporadic Oil Pressure

[davidwhitaker]

Driving down the road and oil pressure went from 25 to 0 and then back up to 10...down gain to 0...back up to 25 and so on. Revving the engine had no effect on the change. It will jump around like this while driving or at idle.
I have a brand new gauge and I can see the oil in the line....it appears that the oil is losing pressure in the tube as it correlates with the gauge.
I put air pressure @25psi in the oil gauge line and the gauge holds perfectly @25psi steady. There is correct amount of oil in pan and there is no noise/knocking from the engine.  I did not see that the temp gauge increased when the gauge started jumping around.

I said all that to say....I really think this is an internal engine issue....my question is What would cause this to happen?

[Rickf1985]

Pump cavitation, Caused by? Could be a clogged pick up screen from gunk in the oil pan. I do not remember if he oil pump is driven by a gear or if it is driven by the distributor gear, if by the distributor gear then the drive shaft could be stripped. Could also be the pump pick up is loose on the pump and pulling air. Broken pressure relief valve spring. No matter what the only solution is going to be to drop the oil pan and see what is there. It would be  good idea to check the rod and main bearing at the same time.

[davidwhitaker]

Low on oil. The dip stick showed close to full but when I drained the pan it only poured out about 1.5 qts. OUCH! Anyway...filled it up and got oil pressure back.

[Rickf1985]

Watch it closely, guaranteed damage was done, just a matter of how much.