I received a report today on the '98 1500 I service that the oil pressure gauge began jumping all over the place. Reportedly it'll go from 40 to zero to the max of 110 (?) and back.

I'm guessing this is a sending unit issue, ground issue, or failing cluster? Or maybe PCM if it controls the gauge?

Has anyone else experienced this?

 

I think the 98 cluster gets its cue from the PCM, as to what to display..... Would be interesting to plug in with a scanner, and see what it reports, though, don't know how quickly the data will update on the scanner....

 

Those oil pressure sending units have plastic top sections and tend to leak after awhile. Check yours closely to see if its leaking oil.

 

I would try replacing the pressure switch first and see what happens, If it doesn't fix the problem, then you would need to hook up a mechanical pressure gauge and see what your oil pressure is at.

 

Yeah this is the plan....if I ever find the time. For now I told them to ignore it unless they hear bad rattling noises from the engine bay LOL

I can't say I recall ever laying hands on the op sending unit on these engines...is it readily accessible?

 

V8 is on the back of the motor next to the dist, on the passenger side. Unless its a diesel it would be the driver, On the block. 1 inch deep socket should work to remove the switch.