mexirican

OK. About a year ago, i got a new radiator. Then 6 months ago, i changed the water pump and flushed the system. Now my cherokee is overheating when I am not moving. It'll get to about 230 or so then stop going up. The weird thing is when I am driving, on the freeway or street, the engine temp is less than a quarter way up the gauge and it takes forever to heat up. My heater blows cold air unless I am moving. When I am moving, it works fine. Then when I stop, it starts to cool off as the engine temp goes up untill the heater is blowing cool air. What is going on???

Also. I am looking to get a hose filler but I am unsure what size I need. Can someone give me a hand?

Here is a link - http://store.summitracing.com/egnsea...view=sku&RC=10

BowtieGuy3

Make sure your coolant is topped off and burp the system...
Next thing I'd check would be the thermostat, and your cooling fan temp sensor.
Those hose fillers are pretty much useless unless you have a closed system, and even then, they really don't serve that big of a purpose.
My '92 does the same thing if it's low on coolant, just be careful when you're topping off/burping, the thermostat has to be open to get it done properly.

mexirican

How do I "burp" the system?

BowtieGuy3

Easiest way is to have the cap off when it's warm and let it run until the engine is hot. Then just start adding antifreeze until it cant hold no more. You might wanna give the upper hose a squeeze to help a little bit, but it's not necessary.
Then when you got it as full as you can get it, replace the cap, and add to the reservoir.

mexirican

Well...unfortunatly, I am cursed with the closed system. Thats why I wanted to buy the filler for the hose, no radiator cap. :-( But will it work the same through the hose filler?

BowtieGuy3

Yeah, just make sure the cap you put on the in-line hose filler is rated at the same psi as the system. The Burping would be the same as the reg. system.

mexirican

Ok. Thanks for the help. One more question though. If I am low on coolant, why would it take forever to warm the engine up?. Im in AZ so it doesnt get super cold here. its in the mid 50s at 4am when i leave for work. Its cold for us. :-P But i drive the whole way to work in the street and never get above 50mph with a 20 min drive.

BuckB91XJ

Gotta question for you. You said you live in Arizona. Did you buy your XJ in Arizona? You never mentioned anything about the thermostat or having the water neck off. I bet a previous owner removed the thermostat for summer driving as a lot of guys do in hot areas. This, however, is not good for winter driving. It causes the heater to not get warm sometimes while freeway driving as the water is always moving and doesn't stay out of the radiator long enough to get warm or it can cause overheating with extended idling as the water is constantly moving and doesn't stay in the radiator long enough to get cooled off. I think a good first step would be to pull the water neck off and see if the thermostat is stuck open or if there is even one there. It is also a really easy thing to fix. I hope this helps.

BowtieGuy3

I'm not sure where it's at on yours, it should be the same, but my coolant temp sensor is on my thermo housing, so the coolant has to get to temp, open the thermo, and flow past the sensor to register, that or just get heated up enough from lack of coolant to spread thru the housing and heat up the sensor enuff to make the gauge crazy.

BlueXJ

You need to burp a closed system a little differently than a open system.
first place the rear end higher than the front. (ramps work great)
Second remove the coolant sensor on the rear of the head.
Third fill the system until coolant comes out of the place on the top of the head where you removed the sensor.
Lastly replace the sensor and fill your expansion tank to the full line (not to the top)
You have successfully burped a Renix system.

mexirican

BuckB91XJ - I did buy the jeep in AZ. I know there is a thermostat because I installed it. When i did the water pump, i changed the upper and lower hoses, thermostat and the housing. I put in the new radiator a while ago, before i knew anything about Cherokees.

BuckB91XJ and BowtieGuy3 - I'll try burping the system on Sunday. i dont go to work and Im staying in this weekend. Too much drinking and partying lately. Have to save for Christmas.

mexirican

Update - I was gonna try to burp the system today but I decided to try it my way first. I detached the upper radiator hose from the thermostat housing to add coolant that way. When I did, water started spilling out the housing as fast as i was pouring it. Then when i started the jeep, water sprayed everywhere. SO...my f-ing thermostat is stuck open. Better than something serious. I still wonder why my jeep would overheat when it is just sitting in traffic yet it wont get to running temp after 30 min of sitting in my garage.

Metmknice

When you are in traffic, unless you have your trans in neutral there is a load on the engine.

BuckB91XJ

Like I said, a good first thing to check and an easy and inexpensive thing to fix. I'm glad that is what it was for ease of fixing and easy on the wallet.

BuckB91XJ

As far as overheating in traffic and not in the garage, could be the difference in the load on the motor when you are idling in traffic with your heat and all your other accessories on...