2002 Jeep Grand Cherokee 4.0L oil pressure gauge reading too high

Better high than low, but if too high, may be a possible stuck oil pressure relief valve. Recommend a shop diagnosing this problem.

Two things...when it reads zero, is there any engine noise (tapping or knocking)? After you rev the engine does the pressure read normal at idle and function normally, or does it go back down? Either way, you should not drive the vehicle 'till you have a mechanical gauge (yours is electro-mechanical) put on there and the actual pressure is tested. The condition may be a bad sending unit, a bad bearing or possible obstructed oil pump screen. The repair is obviously different for each one and the price is as well.

this is normal, as when you start the engine the oil pump starts to work and increases pressure. all is good

its probably the sender. there is no good way to test them without a mountain of tools. its easier to replace the sender i think its pretty cheap

If your oil pressure is running in the red this would indicate too much oil in the system. You should have your oil changed and refilled soon or you run the risk of burning out the oil pump. At idle your pressure should be just over a quarter of what your gauge has. At highway speed it should not exceed 3/4 of the gauge unless your going in excess of 100 MPH. Change the oil and filter and your vehicle should be fine.

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

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!!)

If the weather in your area is colder than normal, your startup oil pressure will reflect this, essentially because it is much thicker when very cold. This high reading should drop to "normal" once it reaches operating temperature. This condition can also be caused by a sticking pressure relief in the oil pump, usually caused by sludge inside the engine. If you regularly maintain your vehicle and use good quality oil, this should not happen. The oil pressure sending unit is also suspect, but in your case, I would not put it at the front of the list. If oil is close to "change time" consider using a good synthetic oil (synthetics flow better at extreme temps) or using a 5W anything oil during winter months. (see manufacturers specs)

try replacing the oil filter and oil make sure u use the right grade oil for it if it still does it u need yo go to mechanic or if u have one connect a external oil pressure gauge to the engine to check if the car gauge is reading correctly if it is reading right then the oil pressure releif vale is stikking

if the car gauge is reading wrong change oil pressure sender

Hi, I had the same problem, same vehicle (same year), same engine. I bought an oil pressure tester at Harbor freight tools for $ 8. I was trying to figure out, if the pressure is really high, or just the sending unit is defective. The tester after connecting it to my engine was reading correct pressure for this vehicle ( between 25-30 PSI when idelling), which showed that the oil pressure sending unit is defective. At Advanced autopart store they want about $ 47 for the sending unit, so I put the defective one back in place (still reading H). I'm planning to replace it after next pay check :o) Good luck. Pavel**