baseballman

My 2000 cherokee 140k has an oil pressure problem after longer trips 20+ miles. At first on a cold start up the gauges look like this at idle



After the engine warms up at idle




After the engine runs for a longer time the oil pressure at idle will fall to just above zero as soon as I press the gas the oil pressure will rise back to normal levels

I just purchased this jeep 3 weeks ago and have kept an eye on the coolant levels and all seems good with that so Im thinking..well more like hoping it is not a head issue ..any ideas?

Oil was just changed by dealer before I bought it..no name on filter should I start by oil and filter change?

Pelican

What makes you think you might have a head issue?

Since the Jeep is new to you the smart thing to do would be to check pressure with a mechanical gauge rather than speculate and worry about it.

baseballman

I don't think that it has a head issue but with everything I have ready about 2000-2001 it is going to be something in the back of my mind

freegdr

Change oil dealers use cheapest stuff ava ...jiffy lube seconds....

cruiser54

This^^, and be sure there's a good oil filter on there like Wix, Napa or Mopar. Not STP, Fram etc.

Aljay

Check with mechanical gauge and move on .
Don't believe all you read about the head issues either , some people avoid the 2000-2001 jeeps because of it and it is just dumb .
Do research before getting all fired up about a bad cylinder head .
Cruiser 54 is spot on /\/\

baseballman

Reviving my old thread because now coolant level dropped dramatically *facepalm* soooo where should I buy a head from....

jebmccall

well first thing you need to do is confirm it is a cyl head... if you just want to buy one most 0331 victimss buy one from clearwater.com.

check the condition of the oil. if it is milky you need to inspect the bottom end for worn bearings and damaged crank journals.

psi test the system see if you have external leaks... you might get lucky
did the engine overheat badly and then start losing coolant? most 331 heads crack due to being overheated and poor maintenace.
whats the current oil psi warm?

also alot of jeeps have oil pressure readings on the gauge like urs did and run forever some of them are even below the factory minimal and run forever.

Cherryokee

You stated "just purchased 3 weeks ago" and "oil was just changed by dealer" in your OP. Don't you think the dealer bears some responsibility in this?

You should not allow them to take advantage of you and your desire to own a nice looking and well-presented Cherokee. They are in a business where they should be aware of potential issues common with certain makes and models. Shame on them if they feign ignorance of common issues.

This begs the following questions:

Is/was any warranty offered in the sale (i.e., warranteed for first 1 month and/or 1000 miles)? Maybe they are aware of this issue by virtue of having seen the oil and coolant condition when they went through it before putting it up for sale?

Done right, unless you bought it "as is/as seen" (and woe to you if you did), you can make the repair expenses their responsibility, if not in-total then at-least partially (50/50?). You have the right to request that the dealer acts in good faith.

Cherryokee

Even if my advice was a month late...

If you paid fully for repairs and saved dated receipts then you are within your rights to present the dealer with the proposal of shared responsibility. If you have done all the right things and they still refuse to play ball then legal action may be a viable alternative.

mike96xj

All my jeeps have done this. Nothing bad ever happened to me. I think pressure drops when at idle and increases pressure while the motor is under load.

salad

All your Jeeps have suddenly lost vast quantities of coolant and nothing happened? Or did you only read the first post lol

Oil pressure is a function of internal bearing clearances, oul viscosity, and oil pump flow. Oil pump driven by the camshaft so yes, it's related to RPM.

playbass

Did you ever verify your oil readings with a mechanical gauge?

Oil pressure sending units are pretty cheap (~20$) if you go after market (though most people will say get one from a Jeep dealer.)

Make sure you do not have an external leak of coolant, don't assume immediately that it is going into the engine.

mike96xj

LOL yeah just read the first post. I was refferring to oil pressure.

baseballman

I really didnt think that it was the head until last night after realizing that my coolant levels had dropped so much that there was a little green on the oil cap I saw when I searched that people run the engine without the cap on and shine a light in there to see if they see the coolant mixing in