I have a 96 Cherokee with the 4.0 and my oil pressure gauge is acting up. I've talked to several mechanics and buddies and we all think that it is probably the Oil sending unit. When I start the Jeep the Pressure jumps up to around 70 which is where it should be but then plummets to about 30/35. If I start going down the road and give it gas it jumps back up to 70. If you do think that it is the Oil Sending Unit please tell me how to change it. Thanks

 

It shouldn't stay at 70 all the time... Normal idle pressure is about 12 on a 4.0. The oil pressure guage on the dash is far from accurate, and it could be that the oil pressure switch is bad. But, the only way to really find out what your pressure is running is with a manual guage.

 

before you go changing anything check your oil pressure with a mechanical gauge they are much more accurate then if it is off substansially change the sending unit or try cleaning it they arent very accurate though even a new one might not be right

 

Thanks guys. I'll give that a shot first.