hi all,
I changed the oil on my 99 Jeep Cherokee Sport a few weeks back. Had a heck of a time getting the oil filter off. It was stuck so bad I had to make a couple of runs to the auto parts store to buy different styles of wrench. the engine sat without any oil for about 3 days. over the past week I noticed the oil pressure riding really high around 80 when i hit the gas, and settling back down around 60. i've read the posts about the sending unit going bad and causing a bad reading at the gauge, but the engine has also started to stall out periodically which has me thinking this might be a legit issue. is it possible that a clot developed while the engine sat dry? i have synthetic castrol in there now with a Bosch 3402 filter.

cheers,
BD

 

The sender would be my 1st suspect. It may have gotten hit while you were fighting with the filter. Synthetic usually causes pressure to be be a bit lower not higher.

 

I wish... my wifes jeep at a warm idle is at like 15 18 psi... :-/

 

Stalling on these things can be several common problems unrelated to engine lubrication.

I'd toss a new sender on there. Do you get any oil pressure reading with the engine off? That would be an excellent sign.

 

Most likely the oil pressure sending unit as already mentioned. It is a very common failure on the 4.0

Do yourself a favor and buy a Mopar unit directly from Jeep. Best bet for reliability and longevity.

 

the oil gauge reads around 40 when the engine is off and the power is on. guess i need to get that replaced. the car has been stalling out more frequently, when trying to park or anytime the RPMs drop down to idle. prolly need to take it in to be serviced.

 

Oil pressure sender is shot. I'd clean out the Idle Air Controller (IAC) before taking it to a "professional".

 

well, replaced the oil pressure sending unit and the gauge reads normally again. also finally got a chance to remove the throttle body this weekend. The TB wasn't too dirty, but the IAC sensor was pretty bad. Cleaned that up and also power-washed the K&N after market air filter. seems to be idling better now, so far so good. thanks for the advice, guys!

here is a good link with photos and directions for cleaning the TB/IAC.

http://www.xjtalk.com/showthread.php?t=10844

 

i agree with everything he wrote

get a mopar unit