I have a 2000 Jeep Grand Cherokee 152000 miles. Recently it has had a few problems. I had the entire front end replaced as well as a relay fan installed. Currently, the oil pressure goes very low to yhe point of the check gages light turnign on while driving. For the first 15 min of driving the oil pressure is maintained, then begins to fail while at a stop. If driving on the highway the oil pressure is fine. I have been advised that it is not worth fixing because it may be the oil pump but could also be an engine problem. Anyone out there with a Jeep with a similar problem or anyone with insight to the problem? Is it the oil pump? Is it worht fixing?
It could be just the pump, but I fear it is a well worn engine. The pump would be worth replacing. How hard a life as it had. I would expect it to be a little worn at 150,000, but not normally that bad unless it has had a hard life.
I would get this checked as soon as possible. It may not be serious. I had the same problem on a Ford Maverick years ago and it was the sending unit that activiated the oil pressure light. It behaved the same way that you describe is happening on your Jeep. The repair cost was minimal.
A good mechanic can check the oil pressure with his own gauge. If the oil pressure is truly low, the oil pump might be the problem. The Jeep might be worth the oil pump. If the engine is truly worn, you might get away with a heavier weight oil for a while.
Jeep oil pressure senders are a known problem area. If it was my car, I would try changing the sender. The best approach would be to connect a mechanical gauge in place of the sender and see what the pressure really is. If it’s a worn out oil pump, replacing it is not a major problem, at least on the 4.0.
Don’t bother fixing anything else on it. It has gone farther than it was designed to go. We’re talking money plus effort plus your patience. Thicker oil may help. To get back to the money factor: If money is scarce; you might want to try the new oil pump BUT I don’t know if it will help. If you can afford a newer vehicle, forget the current one.
What engine?? a 318 or 360 Chrysler? (5.2 or 5.6L) What weight and type of oil are you using? You might switch to 15-40 or 20-50 as a first step…
But it’s only a year 2000!!! That’s not old!! I’ve never had a car for that short of a period of time. Yes it’s a chrysler but it shouldn’t be that bad.
I would heed the advice of replies stating caution about this becoming a potential money pit.
1: Low cost: Maybe it’s the sending unit. A manual oil pressure gauge test would be a reasonable first step.
2: Medium cost: It might just be the oil pump. Get a quote for this and decide if it’s worth spending the money when it may not solve the problem. [I replaced an oil pump once years ago when the problem was a worn engine.]
3: High cost: Worn engine. Do you really want to invest this much money in an 8.5 year old vehicle?
I second the vote for checking the oil pressure with a manual gauge, and if that shows low pressure, then “bandaid it” with thicker oil just to keep it running.
I had the same problem on an 87 Tempo. The paint looked good so my wife wouldn’t let us get rid of it. I got real tired of looking at it. Thicker oil worked well with that old style cam in block, iron engine.