When first starting the 2000 jeep grand cherokee the oil pressure is fine, after driving 15 to 20 miles when you stop the oil pressure guage indicates the pressure dropping near 10 pds or less and the check guage indicator comes on.

Could be the auto shutdown relay is getting weak. Try swapping it with the horn relay.

If the engine is not making any ticking noise, I recommend replacing the oil pressure sending switch,sensor.

find the oil preassure switch and install a tempeary mechanical guage and eye ball the oil preassure it sounds like low oil preassure

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.

First off I wouldnt drive your car until you make sure that you have indeed oil pressure and that the gauge is a false reading, driving your car if in fact it has no oil pressure will severly damage your engine, but firstly i would check the oil pressure switch its located on the passenger side of the engine right back from the oil filter make sure the connector is clean and free from oil and corrosion if the connector appears to be in good shape take a paper clip and insert it between the 2 terminals inside the connector your oil pressure gauge should peak at 80 PSI that tells you that your gauge and all related wiring are good and in working condition, secondly remove the oil pressure switch and hook an manual oil pressure gauge up to you engine and start the engine the guage should have a oil pressure reading anywhere from 30 PSI to 55PSI depending on engine temperature if theres oil pressure on your manual gauge replace the oil pressure switch with a new unit, if you still have 0 PSI on your gauge then stop your engine immediatly and start looking at your oil pump and lubricating system for a problem.

you blew your head gasket.

ook up a external pressure guage where the sending unit is you will know forsure. with the milage i would guess that the oil pump may be the prblem or to much clearance in yhe bearing.

Try replacing the oil pressure sending unit

Any waranties left? Is oil full? Any noises from engine? Did you put a mechanical gauge on it and check "real" oil pressure? (I would not drive it 'till I was sure about actual oil pressure!!)

The sending unit would be the first thing to change, at least it would eliminate that.