My 87' 302 custom is having oil pressure problems. It drops down to pass the L It burrys the needle then it will jump right back up....Already replaced the oil pressure switch yesterday and it started doing this today. It had always looked a little low to me. But never did it do something like this!! Is it the oil pump????

 

Got a mechanical gauge you could test with? Harbor freight for about $10. My stock gauge did this a few weeks ago and the mechanical gauge stayed at a steady 20PSI at idle and 45 at speed. The stock gauge seemed to fix itself after a few trips around town. Maybe debris or something in the oil passage. Don't know, but the mechanical gauge will tell the tale. I was really happy to have installed my mechanical before I had this issue.

 

http://www.harborfreight.com/automot...kit-98949.html
I found one for 20. Is that the one you were talking about.

 

Nope, get this one. You won't use the amp gauge, but the oil pressure and water temp will benefit you. Run a tee fitting in the original oil pressure sender hole and run both the electric and mechanical gauges. That way you have a backup and you don't create a "Dead Gauge" on your cluster. Orielly Auto or Advance Auto can put together a tee for you for about $5.
http://www.harborfreight.com/electro...set-41017.html


I'm running a tach and a oil pressure gauge, but you could do the temp and oil pressure where mine are.

 

i like that set up i have been having problems with my oil press. so i will order this so i know exactly what i have.

 

Check the ground on the motor, sounds like electrical problem, the only way the oil would bounce like that is a loose pump or pickup. Bad pump or bearings would still have consistent pressure, it would just be lower.

 

I was thinking the screen on the pickup could be clogged??!! And the ground is good.

 

Electrical on the gauge itself can cause issues too. The gauge can fail. I know for a fact that my oil pressure never changed when my stock gauge showed major drops in pressure thanks to the mechanical gauge.

 

Im gonna drop the pan and check the pickup. Anybody know a way to do this without pulling the engine.=?