Overheating Issues

[Cascadia]

My LJ has been overheating lately. It is fine while driving but if I come to a stop for more than 30 seconds, the temp jumps up super fast. Ive heard of Jeeps having issues with cooling in Moab in the summer but why in Orem? Do I need to get a bigger fan or what do people with the same issue recommend?

 

[Spork]

Not LJ specific suggestions but how are your coolant levels? Any leaks? Anything blocking airflow through the radiator or how is the radiator cooled (engine driven fan or electric?) Bent fins on radiator? mud or dirt blocking air? Are your radiator hoses kinked or compressed decreasing flow?

Other than those suggestions blockage in the radiator? Broken thermostat?

 

[jswainthug]

Sounds to me like a thermostat. While driving the air movement is enough to cool the motor, but when stopped it heats up. Just my .02

 

[Cascadia]

I've got no blockage in the lines. No kinks, the only thing blocking airflow is the winch but that's been there for years with no overheating issues. Coolant levels are normal, no leaks, I'd guess it's an electric fan but not positive. No mud or dirt, or bent fins on the radiator. I thought that if a thermostat goes bad or is going bad it is either stuck wide open or stuck closed...not closed when you're sitting still and opens up when you move. Am I wrong?

 

[mbryson]

I'm assuming your fan is running while overheating? (seems like I had something happen with my 4.0L re: the fan switch turning the fan on/off)

 

[Jesser04]

I would change the thermostat it sounds like it's stuck open.

 

[MOODY]

My electric fan on my old XJ crapped out, and did just the same thing.

 

[Cascadia]

Well I guess I'll go out and turn her on and let it run til it heats up and make sure that fan is running. I thought it was but I'll check again.

 

[redtoy]

fan clutch? If it has a manual fan. While moving it is getting air through the radiator but when you stop then no air flow.

 

[redtoy]

Well I guess I'll go out and turn her on and let it run til it heats up and make sure that fan is running. I thought it was but I'll check again.

If it is the fan clutch it will appear to be spinning

 

[Cascadia]

K. I finally got it to overheat. The fan stayed on the whole time. It's an engine driven fan. It got up in to the red and I decided to check something. It didn't matter if I was driving around to cool it or sitting still. I kept my foot on the gas at around 2500 rpm and the extra wind from the fan took it back down to normal. So what say ye on my dilemma?

 

[Jedisdead]

waterpump? not flowing enough coolant at low rpms had a probe that didi that. The heater would also only work when the motor was reved

 

[Cascadia]

Heater blows very hot when I turn it on but when the a/c is on and it starts to overheat the air tends to get a little warmer. Are there other symptoms of a bad water pump?

 

[OrvisKrawler]

change the thermostat

 

[jeep-N-montero]

Thermostats are less than $15, change it and report back. And the thermostat housing is at the front of the engine where the upper radiator hose connects to the engine, just make sure you don't over torque it and crack the housing. Takes about 20 minutes total.

And highly consider upgrading to an electric fan, it keeps things cooler and gives you 5-7hp.

 

[krany]

Thermostats are less than $15, change it and report back. And the thermostat housing is at the front of the engine where the upper radiator hose connects to the engine, just make sure you don't over torque it and crack the housing

emphasis on that, only really just needs to be snug. i craked mine, its another 30 dollar part to fix it.

 

[Cascadia]

Where do you mount the electric fan since the stock fan is so close to the radiator? Or do you just take the fan off but leave the pulley so that it can still turn everything else and mount the fan to the back side of the radiator?

 

[krany]

yea just un bolt the fan bolts and put the new fan behind the radiator. look for a ~95 ford Taurus 2 speed fans, i have herd that they work extremely well.

 

[Corban_White]

It is probably the fan clutch. With those type of clutches they always spin but they don't engage all the way until the temp gets up. The clutch is probably not ever engaging all the way. I had the same problem on my truck and replaced the clutch and it has been fine.

 

[Cascadia]

So you're thinking that the clutch is allowing it to spin but not engage all the way then...just not spinning fast enough at idle? Should I still worry about the thermostat? I was just on my way to the store to get one and try it out.