Oil pressure gauge drops to zero sometimes when idling. When gas is pressed to move the needle goes back up. It does not do it all the time

SOURCE: oil pressure gauge goes up when car started, but then down to 0

u Have a problem with the oil sending unit. The sensor is located beack right side of the engine block. Take out the switch and make sure u have good oil PSI. Should be 6 psi at idle and around 50 at 4000 RPM. If the presure is ok replace the switch they are very cheap about 20 bucks. Please rate.

SOURCE: Oil pressure Gauge drops to

Change your oil pressure sending unit? it wouldn't be my first.

SOURCE: 94 jeep grand cherokee oil pressure and engine temp?

I'm guessing your engine is'nt making any tapping noise with the low oil press.
Your oil pressure sending unit is most likely the culprit.
Is your car smoking when the temp. goes up?
You engine could be air bound or thermostat could be opening too late (might need new one).
PLEASE DO NOT OPEN THE RADIATOR CAP WITH A HOT ENGINE.

SOURCE: oil pressure drops at idle

oil pump is going bad or there is problem with oil pressure witch have it check out because if oil pressure is low it can cause serious engine damage. Have it check out soon hope this help

SOURCE: 97 wrangler oil pressure drops when engine is at idle

check the engine oil level... you could possibly need to replace the oil pump soon... if you do not live in a cold climate i would consider using 30 or 50 weight oil. do NOT use that in a cold climate as the oil is like molasses when it gets cold.
that's only temporary. one other thing to consider is a clogged oil filter... when was the last time it was changed ?

Robert