Started yesterday stuck in traffic for an hour. Yuck! Started smelling antifreeze- looked down and I was half way into the red. Busted a U-turn through construction (thank goodness for 4x4 and 4" of lift!) and got moving. Cooled down but now every time I sit still it starts to overheat. This was never a problem before...

I tightened my fan belt this AM and topped up with some antifreeze (I was about a quart low) with no luck. Just as bad on the way to work. As long as I am moving about 40 MPH + it cools right down, but sitting at a traffic light will put it up to the red if the light is long.

Checked once I got to work and I don't think my electric fan is working any more- would that alone do it or should I check/replace my fan clutch? It used to only do this if sitting in traffic for a while and it was a hot day.

Cheers!
~K

 

is one of both fans are not working,, then most likely that is your problem

 

Well I know my electric fan is not working (I believe it used to)-

I will go to the JY and get another one tomorrow. I will also look at my fan clutch once it cools down.

 

overheating at a stop and the motor going back to normal when moving is 75% of the time the clutch fan. the other 25% its the water pump and if its the water pump you'll know in a week bc itll start leaking everywhere.

 

Install a hood vent, why bake your engine by keeping the heat in?

 

I would put money on the e fan, It is a one speed fan and you will be able to hear it running. Also if your lower rad hose does not have the internal spring (prevents collapsing), this could make it spike into the red when your temp gets around 230.

Does your temp gradually go into the red or spike all of a sudden?

 

thought i heard somewhere that if you turn on the AC the electric fan should come on, mine doesn't have AC so i wouldn't know for sure but maybe try it out to see if the fan is working

 

I'd start with the fan clutch. When the Jeeps shut down and you try to spin it there should be some resistence, also check for oil on the front of the clutch itself, if its leaking it's faulty or about to be. A second method of testing (takes two people) is run the engine, one person watch the fan, the second shut it down, the fan should stop spinning right after shutdown, if it continues to freewheel it's definately faulty. I'm not sure how the electric fan ties in on a non a/c model, I'd go to the manual on that one. Theres my .02.

 

you could just hook up your electric fan to a toggle switch and just cut it on when it starts to get hot if the fan works.

 

I say water pump failing

 

I believe it is the fan clutch- it just doesn't feel right when I spin it by hand without the engine running. I will check it with a helper later.

No leaks at all yet, and I do drive 45 miles each way to work every day.

I also checked the fluid level with the engine cool from the radiator cap and it was low (even though the overflow bottle was full). Added about 1.5 quarts and no more overheating at a stop but it does still get warmer than normal. Not to the red but about 220.

 

Our jeeps do not have a tall radiator, therefore, it relies heavily on the electric fan to assist the mechanical fan when you are at operating temp. I would try the temp sensor at the thermostat, then the electrical fan motor. the fan clutch alone will not cause this problem as it cannot cool the engine by itself in warm weather while you are sitting still