Hello,

I had thought I had fixed my overheating issue. I had significant overheating last summer 2012. I had the following repairs done last summer. Over the winter I drove my cherokee, had no overheating issues even drove to the mountains. The parts replaced have been:

fan clutch
thermostat
thermostat housing
coolant expansion tank and cap
eletric fan sensor
car had coolant flush last summer

I used to have the issue that the car would overheat on the highway, and found that my fan clutch was bad, that was replaced last summer. Now as summer approaches again, the car gets hot at idol, about 220-230ish after driving around. While in motion the car stays just below 210. It was about 90 degrees out and got to the mark right after 210, I think about 225? This was whenever I got to a light or let the car idol. Just for kicks when I stopped the car and let it idol for about five minutes, it stayed right at 225, never went into the red. Shouldn't the electric fan be kicking on at this temp? When I turned on the AC the electric fan came on and the car started to cool. I swear I have had that electric fan sensor replace three times now... Just to clarify it had yet to go actually into the red but we havent even hit the dead of summer and I am afraid to see what happens when it gets to 100.

Thanks for the help!

 

So, can you verify that the e-fan actually works? Perhaps the water pump is worth some consideration as well, or maybe your radiator isn't flowing as good as it could be. When you turn on A/C, what temp does it run at?

 

I apologize water pump was replaced last year as well. When AC is on temp gauge runs about 210, maybe a little over but not as hot as when AC is off, the electric fan does come on when the AC is turned on. I don't think I should have to run with the AC on all the time just to keep the car on right?

 

Sorry to keep the car cool*

 

Of course things like the E-fan, fan clutch, and the fan shroud are what need to work if you are stopped or going slow.

Agreed with pockets, make sure the fan is on. It comes on around 218*, (& AC and defrost)..I leave my expansion bottle 1/2 empty, so there is air there to compress. It'll still pop, but it seems to take longer that way!

 

Replace the radiator.

 

I agree. Crossflow radiators don't flush well at all.

 

Might consider upgradeing to open cooling system if your gonna get a new one .JM2CW

 

I agree, I'm thinking its the radiator as well. Its really the only component that hasn't been replaced. The car only has 80k but I think it was sitting for quite a while. E-fan is working but when i put an IR gun on the spot where the sensor is for the E-FAN it is only showing about 175-180, but at the thermostat housing and back of the head I am getting around 220-230.

 

Idk about the Radiator. It works fine cruisen, and overheats parked at a light. Temp comes down with the E-fan. Myself I'd be curious about the new clutch, and why the fan is not coming on. Or is it working?

I didn't see any mention of the shroud. It's there?

 

Over heating when stopped idling and not when driving.
Normally pretty straight forward.
2 things,, maybe 3

1-clutch fan (They can be put on diagnostic mode permanently, a little bit loud but cools very well)
2-Radiator. I replaced my old one because i got a branch in it. It was not overheating before but under torque and low rpm, it easily got hot. With the New rad, no matter what I do, it stays cool. I guess it was due for replacement. Thanks mother nature.
3-fan shroud. Broken shroud reduces your fan efficiency DRAMATICALLY.

When I switched to synthetic oil, (amsoil.com Zrod 10w30) I noticed a slower warm up time. The thermostat stills keeps it at normal temp.

 

Shouldn't need any fans (efan or mechanical) at high-way speeds. Fans r for low/no speed driving. Replace the rad.

 

half the tubes in the rad are probably plugged, try a new rad, or even throw it in neutral at idle that might help a bit.

 

Where's the Night Gallery Music. "Do do do do ". Why am I the only one who get's it? If it's cool moven, and overheats stopped, it sounds like airflow. The rad...maybe the fins OUTSIDE need cleaned. Granted a new rad might tip the scales enough, but the symptom's points to airflow to me. Still no info on the fan shroud.

 

Excellent point......gotta have good airflow at all times.