Air locks and guess work - help needed

[jeepgirloz]

Looking for some ideas....

My 95 Jeep cherokee sport is running a little hot - local mechanics won't touch it (so no help there) - will drive it 300k north to find someone (anyone know of good jeep mechanics in Darwin NT OZ?)

About a month ago there was a small coolant link from bottom radiator hose, easily fixed. Some bubbles from radiator - (as usual the mechanic thought the head gasket must be blown - this has happened to me 4 times in the NT!). Then realised it was prob just air lock from coolant leak. Ran them out (for 20 mins or so?). Since then things don't seem to be the same - has had 2 pressure test and no leak but she's getting to 100 fairly easy (and its build up time around here) and not settling when idling. Thermostat is reading correct temperature and opening at about 75 - 80. New thermostate and radiator flush 1 year ago.

Could she be running a bit hotter because there might still be an air lock in there? or is it likely something else?

Guess work from jeepgirloz

[1996Chreokee]

Make sure both of your fans are functioning.... the one on the drivers side is an electric fan... the problem I had with mine was the air conditioning refrigerant was low and not allowing the secondary fan to cycle on...

With the engine running turn on your a/c and you should hear the a/c compressor cycle on right away and the fan should come on shortly thereafter... the compressor should not click on and off repeatedly for only a few seconds at a time...if the refrigerant is low just add some and your fan should take right off


one other thing when you flushed your radiator did you have a shop do it or did you just use a chemical from a parts store? I never had much luck with the parts store chemical.....

to check the radiator... get the jeep up to operating temp and shut the engine off.... feel the front of the radiator (from the grill area) not the fan side for saftey reasons and make sure there are nocool or cold spots on the fins of the entire surface.... at this time you can make sure the fins are all in good shape too... get luck let me know

[AlohaBra]

Defenitely those two things...fans and radiator.
Let us know after you determine the condition of fans.

Aloha from California...

[Chrysler-Tech]

Why did you dismiss the head gasket diagnosis?

[AlohaBra]

OKay...on the head gasket...the guy is in Austrailia..Northern Territories..

So...if you are going to start down that path..put a pressure gage on the radiator and see if it is going to go up super high. You can also use a dye checker or a Carbon Monoxide tester like a smog test sniffer that we have up here in the States.

On a 95 4.0L that has been maintained, that is not a common occurance (do a search on this forum or "google")...
What engine do you have anyway...when I was in OZ...they thought that the 4.0 was too gas thirsty...

Aloha...and best regrards..

[fredjacksonsan]

Air bubbles could be the cause, I'd try parking it on an incline with the front about a foot higher than the rear, radiator cap open, to see if you get more air out. If not....

How many K's on the Jeep? At 11+ years old, if you've got a lot of distance on it (and all fans are working) you may be looking at enough of a radiator restriction to cause the overheating. I've seen many vehicles (both in person and on AF) that were fine in cooler temps, but when it came around to summer they began to overheat.

Also, you may want to check out this guy's site, and descriptions of how he solved his overheating problems:
http://www.go.jeep-xj.info/