Newbie to this forum. 2000 Cherokee 4.0L. Coming down 15% hill, I geared down to 1st gear (Auto Xmsn). RPM went up to 3500 max, then I started braking to slow to 20mph; then repeated the technique, to keep brakes cool.

Noticed Oil Press climbing up to 80 (40 is Normal) at higher RPMs. No Check Engine lite. Oil level normal & did not appear to be frothing. At idle and cruise (30-55 mph) Oil Press seems a tad high but near normal. Seems tied to the RPMs. Using 10W-30; ~90,000 tender miles.

Opinions please. Thanks.

Thudman

 

sending unit maybe?

 

80 is not very normal, but i don't see an issue.

 

Pick up a Haynes manual the oil at idle can get to as low as 13psi and above 1600 rpm it can range from 37 to 75 psi it fluctuates..maybe check your gushes as well

 

Is there a check valve in the oil pump that could be acting up? My oil press has never acted like this. Definitely not normal for my Jeep.

As shaneo417 says, it may be an oil press sending unit.

Thudman

 

Sending unit imo. I just changed mine out recently, had similar symptoms. It's a common thing with Cherokees.

 

I think the problem is the Sending Unit. When I started a few minutes ago, oil press went to 80 @ idle. Is the Sending Unit just above the oil filter? Or is it under the dash? How to change it?

Thudman

 

on your its right by the oil filter, you should see the wires going to it

 

you could always hook up a mechanical pressure gauge to it and find out before you go and buy a new sending unit

 

theres a similair post on here about this and im actually having the same problem at the moment. if its taching out or figgiting, its most likely the sending unit like whats been said already. if its reading over 80 from 1600 rpms and above it sounds just like the unit went bad.
fixed mine and it went back to the normal ranges.

 

Mine will hit 80 when its cold, depending on the rpms but once its warm it sticks to right around 40. Mine fluctuates like a preggo *****. Havnt been worrying about it, its been doing it sense I bought it. I wouldnt worry about it myself...

 

hopefully you guys get er figured out, keep us posted (just in case down the road mine acts up :P )

 

It was the oil pressure sending unit. R&R'd it and oil press normal (~40 psi). Cost at Advance Auto was about $44. I know, I know, I coulda got it cheaper online. But the info the guy gave was worth the purchase at his store, since I had not done the install before. You'll need a 1 1/16" deep socket (cost ~$6). Adv Auto had a 1/2" drive, but I already had a 3/8' to 1/2" adapter. I'm happy; Adv Auto is happy.

Thudman