I have a 91 Cherokee that I bought a few months ago. My oil pressure was ok when cold but would go to 0 when hot. I always thought it might be the sender or the gauge.


I pulled the pan to change the rear main seal and found the oil pump pickup tube full of crude. I changed the pump and the pickup tube. It has normal oil pressure at cold temps now and never goes to 0 anymore. I have put over 2000 miles on the engine since then.


Not sure if this is your problem, hope you find a solution.


Mike

 

I feel wrong about selling it knowing there is a major problem so I might as well just drive the jeep. The engine is smoked anyway and at the moment there are no problems with performance, noise, or temperature. What do I have to lose with free triple AAA towing. I need to get back and forth to work.

And I'm not saying a new head will fix it but I can feasibly do it in my apartment parking lot and it could be a band-aid for now. At least it will stop the water from coming in and the bottom end my survive for a few months so I can get to work and save some cash $.

 

You may be able to score another used motor for similar price as a replacement head. If you have a buddy who can help swap a motor. Apts aren't always so hot on that driveway replacement! ha ha.

 

If you could get another head cheap enough, maybe ....


I know these things are more complex, but I replaced a head gasket in an old Chevy six in just under four hours.


But your original problem was the "low oil pressure" so probably not getting far at any rate

 

Buying another head, having the machine shop go through it, the gaskets, and so forth is going to be a couple of hundred bucks. That's money you can put towards an engine replacement.

I would plan my action based on how much coolant you are using. How fast does the level drop in the coolant jug? Check it every morning after its sat overnight for a good baseline.

If its not dropping noticeably then I wouldn't do anything with the head. Even if it drops 1/4" in 3000 miles its not going to destroy the engine. People who end up this way are filling up the jug once a week, once a day, or every 10 miles.

 

It is not losing much at all. Very small amount. I only noticed because the oil pressure an saw a drop in the valve cover

 

Zero oil pressure will probably get it first. Drive it till the cam is shot out through the radiator.

It's OK to sell it as it is as long as you disclose the problem. Let the buyer make his own decision.

 

How much do you have to rev it up to get some oil pressure?

 

So soon as I throttle up I start getting pressure

 

Might be a stupid idea, but if you're going to just drive it maybe give it a little throttle at stoplights, and of course don't leave it sit and idle.


Who knows ... if it was an old Chevy pickup I would say get a new head and pull the pan and slap new bearings in it without pulling the engine. Might get a lot more miles out of it ???


A Cherokee is not so easy to do an "in-frame" I reckon ...

 

The cam bearings could be what is shot and for that you either need to take the front end off or pull the engine.

 

Easier to ****** the whole thing out and do it right.

Easiest of all is to get rid of it.

 

Okay, well I did a ring and bearing in frame on a 292 for somebody long ago. Don't remember if I did the mains but definitely didn't muck with the cam. It was basically just a farm truck and was burning oil. His dad kept letting it run low on oil


He still has it and uses it for firewood so it must have worked okay

 

I finally got around to pulling the valve cover off the engine. Sure enough there is a small crack between cylinder 3 and 4 exhaust port. Coolant is coming out and running down the push rod hole. I am going to pressure test the cooing system to try and pin point exactly where coolant is seeping out of. On another note is 10-12 psi a good range to pressurize the system?

 

well I do know that 20-50 weight oil will give you more oil pressure I had a similar issue when I first bought my Jeep believe it or not I ran some of the 20-50 weight oil through it and started to of course get more oil pressure the check gages light never came on again at idle so I drop down to 1040 never seen that thing since maybe the heavy weight oil on block some crud give it a shot what do you got to lose at this point