99 Jeep Gr Cherokee OIL PRESSURE at Idle?

CAFISHEL

MEMBER
1999 JEEP CHEROKEE

This MORNING my Jeep started acting up. It is a 99 Grand Cherokee Limited (4.7) with 72k miles.

In drive my oil pressure is WONDERFUL however at an idle it slowly drops off until my "check guages" light comes on (normally I idle at 20 & it's falling WAY below that).

My vehicle is FULL of oil & there are no noises or leaks. There are NO fluctuations in my oil pressure guage what so ever. It just slowly goes from 40 PSI when driving to nothing (if I'd let it dip that low) when stopped/idling.

Up until this morning there have been no warning signs, etc. I keep a close eye on everything with my vehicle & today was the first indicator- and very scary at that! I was at a stop & the "check guages" light came on. I turned off the vehicle IMMEDIATELY but was in a bad place so had to turn it on & at that point I noticed it pick back up to the 40 PSI. As sitting it dropped but if I hit the accelerator to move my pressure came back up. I was able to get the vehicle home & park it.

Now what do I do to fix it? Because of no fluctuations I'm PARANOID it is the pump. Any insight? What else could it be?

1 Reply

MAXAV

MEMBER
2 POSTS

I'm having same problem. I read on another message that there is a strap that runs from engine to firewall (ground) and that the connection may not be a good one. I tried it and so far it seems to be working. My oil pressure went back to 40-45 and hasn't dropped below 35 psi yet. The strap is about 1/2 in. Wide and comes from behind the engine on top and goes to the passenger side of the fire wall on top.