While under driving conditions the oil pressure usually sits at roughly 32 or so when cruising (operating temp) and at WOT goes to roughly 40 (operating temp). However when I cut the ignition the gauge does not drop to zero. Why is it doing this?

 

bump

 

What does the gauge read with the key on and the engine off?

 

Just checked earlier. Car has been parked for 2 days. Put key in, turn ignition ON, and needle sits at roughly 15 psi, right at the start of the red zone on the gauge.

 

Maybe this might help:

From the FSM for a 1987 Camaro (you don't specify make year or model).

1. Unplug the wire at the oil pressure sender.

2. Turn the ignition switch to run.

3. Jumper the wire you disconnected in (1.) to ground.

4. If the gauge now reads low, replace the sending switch.

5. If the gauge does not read low, check the sending wire for opens and the printed circuit on the back of the cluster for cracks or flaws. If the wire and printed circuit are OK, replace the gauge.

There's some assumptions you can make before you dive into this. Steps 1-4 are pretty straight forward.

If Step 5 shows that the gauge does not read low, just forget checking the sending wire and printed circuit. Just replace the gauge. Since the gauge does respond to engine speed, etc., you can assume that the sending wire and printed circuit are OK.

 

I also discovered if i turn the key back to RUN after shutting it off, the oil pressure needle will drop to zero. Just not on initial shutdown. Eh. Just 80s electronics I guess.