Engine has ~50psi oil pressure on cold idle. 20-35 psi hot idle. Sometimes, when the car is in the process of warming up and at idle, I notice the oil pressure gauge bouncing around erratically. For example if I'm idling it will be around 35 psi and start jumping up and down between 25-35 psi for a second, then it will end up at around 25 psi. Once the car warms up it usually stays at around 20-25 psi without jumping around. Is it the gauge or could it be mechanical?

 

Hook up a mechanical gauge and see where the pressure is really at.

 

Don't mean to hijack your thread, but I have a similar problem with my 1994 Z28. Oil pressure is fine when it is cold. After warm up, pressure fluctuates between 20 and 30 around 1000 rpms. Fine at idle or if above 1000. I plan on changing the oil pressure sensing unit when I seal the intake in a couple of weeks.

 

That was the plan, but if I saw an overwhelming response that people have similar problems and it was the sending unit, then I would have just invested in that over buying a new oil pressure gauge, pod, etc.

Cool be sure to post up your results.

 

Changed oil pressure sending unit this weekend and oil pressure is now steady after warm up. I'm glad I did this when I had the intake manifold off because it is much easier to access.

 

Glad to hear all is well.