Oil Pressure Gauge Jumping

[bobs78]

Got a strange problem with the oil gauge in my '78. The oil pressure gauge jumps/vibrates at idle. It only does this at idle. Once I increase rpm or drive the gauge stops vibrating and shows constant pressure readings. Its the original gauge and sender to the car.

Any ideas what is making do this? Thanks for your help.

[JohnZ]

The sender is getting Alzheimer's in its old age.

[bobs78]

That's really sad...at only 28 years young too

THANKS

[Hib Halverson]

First, check the oil pressure with a second gauge and use a mechanical gauge to eliminate both the stock gauge and sender. If it does the same thing, then you may have a problem with the engine oiling system.

If the second gauge does not fluctuate, then check the sender with an ohm meter with the engine idling. If the resistance varies significantly but in a cyclical manner, change the sender. if the sender is ok, replace the gauge.

[bobs78]

Thanks Hib.