I have a 98 XJ with the 4.0 in it. I have had overheating problems for the past few months and it's driving me crazy trying to figure out what is wrong! I have replaced both radiator hoses, had a radiator flush and replaced the water pump and it still overheats. Yesterday I was driving down the street and things were fine, as soon as I stopped and parked the radiator was hissing and all my coolant came pouring out the front! Somedays it drives great and others it has serious issues. I always seems to smell coolant when I am driving if that helps. Please help me, I am going crazy!!

 

Oil Milky? Burning coolant?

Head Gasket.

 

Just checked the oil and it seems ok. Plus the car doesn't drive bad at all, no sputter or problems when starting or slowing down. What are the signs of a bad radiator or heater core?

 

I always seem to smell coolant even if the car has sat for long periods of time. I think it's b/c old burnt coolant is all over the place, that smell it way too familiar.

 

Improper cooling

Perform a pressure test, that will rule out the rad if it passes.

I have seen the O ring on the water pump leak discreetly enough to dump massive amounts of coolant on a short trip. I take it you have inspected every inch of the engine bay for white/green build up?

Also check heater hose near firewall, is it really squishy?

 

If my rad was puking out coolant...I'd buy a new rad. I'd say puking coolant was evidence enough.

 

you didn't mention thermostat valve.

 

x2 Diesel
Pressure test the first thing you want to do if you suspect a leak.

 

Thanks for all the responses guys, I think I will go get her pressure tested. I just had a radiator flush a few months ago and nobody mentioned any problems. The heater hoses are in great shape and the thermostat valve is brand new as well. Here is the one problem I keep noticing, whenever I fill the coolant/radiator up there is always tons of brown gunk in the reservoir and on the radiator cap, could that be anything?

 

If you just had a radiator flush you shouldn't have anything but nice green coolant showing when you remove rad cap. The brown gunk, is it particles, or is it liquid?

 

I just dropped it off to get pressure tested. The gunk is kind of like brown mud. It's not a liquid for sure.

 

I say your radiator is clogged.

 

Great news!! Just got a call from the shop and they said it was just air pockets that were in the cooling system.

 

How is this possible? These systems vent through the overflow bottle, don't they?

 

Yea, if he has his year right it does.