Hi I’m new to this forum and just recently picked up a 1995 z28. The oil pressure at idle is below the 20 psi but above the red so maybe 5 to 10ish psi? and no check gauges light except a hand full of times. Driving she sits between 20-35 psi. I don’t know much about this car yet except it has a mild cam and has 206582 miles. I feel like the idle is quite low too at 500-750ish this issue is only when fully warmed up. When cold she has 40 psi at idle. I’m using 10w30 vavoline maxlife

 

Idle speed is programmed in the PCM. Fully warmed up auto trans is 650 RPM in neutral, 550 RPM in gear. Manual trans is 800 RPM. At cold start, idle speed. Is determined by coolant temperature, and can be above 1,000 RPM in very cold weather. As coolant warms up the idle speed drops.

The minimum acceptable pressure at idle is 6 PSI, below that the CHECK GAGES light comes on. A seriously worn engine might run 10 PSI at idle, warmed up. Oil pressure varies with engine RPM. A Chevy small block (warmed up) needs 10 PSI for each 1,000 RPM……. so 20 PSI at 2,000 RPM, 30 PSI at 3,000 RPM, 40 PSI at 4,000 RPM, 50 PSI at 5,000 RPM.

Sometimes a cam install in a high mileage engine results in failed cam bearings and loss of oil pressure.

 

how would I know if the cam bearings failed? And is it hard to do In the f body? She still pulls and has decent power

 

Can’t tell without opening up the engine. Cam removal is complex:

4th Gen LT1 F-body Cam Removal

4th Gen LT1 F-body Cam Install

 

I do not remember what signaled my 70 Formula cam bearing failure now. Many years ago. But I have to assume it was obvious by the noise. Probably low level knocking. Louder as the oil warmed?