oil pressure gauge problem

my 88 cherokee has a 4.0 l6. when the jeep is running, my oil pressure gauge is all the way at the right side. then it falls back all the way left. it does not give me an acurate reading, it just goes left and right somewhat fast. the engine idle stays the same while this is happening.
it even does it while im driving.

Hi there, unplug the oil sending unit, clean it with contact cleaner and add dialectric grease after blowing it dry, this cured the problem on my 94 XJ 4.0 HO, it started doing the same after I did and oil and filter change...

good luck
German996

Oil pressure sending units (aka: oil pressure switch in some parts stores) are a very common failure on the Jeep 4.0 If cleaning doesn't cure problem, replace it. I would recommend buying one directly from Jeep for best accuracy with your factory gauge. I have had mixed (poor) luck with aftermarket oil pressure sensors. Only takes a couple of minutes to change it out...Good Luck!

FYI, usually;

A Oil Pressure Switch is a Switch that throws at a certain pressure to turn a "Low Oil Pressure Warning Light" On/Off.

A Oil Pressure Sender is a sensor that provides a signal to operate an "Oil Pressure Gauge".

So if your getting a new one, make sure you get the right one/use the correct term when asking at the counter. Yes, sometimes they mix up the terms in the listings.

If you put a Switch in for a Gauge, you'll get the Gauge Needle to peg out when your below min oil pressure and then drop to zero when your above min oil pressure. Vice-a-Versa, the idiot light might light dimly at high oil pressure.

alright cool thanks. ill try that and let you know what happens.