I have a 1993 Jeep Cherokee. I just changed the oil and noticed ( hasn't happened before) the oil pressure gauge occasionally jumping around erratically up past the last line. I changed the oil filter again and it is still happening. Suggestions as to the problem? What should the gauge be reading normally? Thank you!

did you use correct oil weight could be sending unit. high miles?

Not sure about your car, but alot of times the oil gauge sending unit is kinda close to the oil filter, and maybe during the oil change the wire connection was removed or damaged. Turn the key on and engine off ,and if the gauge reads 80psi then the sneding unit might be the problem

Most likely is the sensor. Is it leaking oil? Most do when they start to go bad.

Very first thing you need to do is install a mechanical pressure gauge on there to verify what you see on your gauge. If the actual pressure is low, then it's time to start looking inside the engine. If not, then you need to trace out the electrical problem but will know the engine is safe.

OIL PRESSURE SWITCH-I'm not sure if this is the gauge sender, though. 1995 Jeep Grand Cherokee 4WD 4.0L MFI 6cyl The Oil Pressure Switch is located: Under hood, passenger side, lower engine area, above oil pan, mounted in engine block.

could be a poor connection at the pressure sending unit or a partially obstructed oil pump pickup screen. If internal, often adding marvel oil will help dissolve any carbon or sludge and help with that. Also check the connection at the sender. Can also be the sender itself going bad. Pressure will normally rise and fall with engine rpm but should remain steady if rpms do not change.

My jeep also has started doing this. I replaced the oil pressure sensor. Sensor on the 4.7 is above the oil filter, follow the wires, typicaly is a 1 1/16 socket.

it could be the sensor you should look at the oil pressure relief valve

Check the oil level. Quick lube centers often forget to refill oil, replace oil filter or drainplug. They're in such a hurry to make a buck that mistakes happen.

check the oil sending unit its on the passanger side right by the oil filter.See if it is unplugged or broken.If the oil was change resently that could be your problem