Hey guys, I'm stumped on this one. Jeep runs fine in both rush hour traffic and easy riding. If I turn on the a/c, the temp gauge slowly will start to creep up from the half way mark, it got as far as 3/4's and I turned off the a/c, once off, the temp gauge returns to it's normal half way mark. Belt looks fine, coolant level is ok, no blockage to the air intake, a/c blows cold the whole time. Any ideas?

 

Do you know for sure if the radiator fan comes on?
It should be coming on for the a/c, and it should come on BEFORE the engine temp gauge begins to climb.

Also, do you have obstructions in front of the grill?

I know you said no blockage to the air intake, but I see you have a winch.

Is there any chance you have mud/debris in the radiator fins?

 

x2 on the fan or mud/debris

 

fan comes on, no mud/debris in the fins other than some bugs, didn't think those would be enough to cause anything and if it was the rad, would it still blow cold? Will clean out the bugs and see if that helps.

 

Bugs would be in the a/c condenser. Have you looked at the engine radiator behind the condenser?
It's kind of hard to see. You may have to remove the plastic cover over the top of the two.

I guess it depends on if your JK has ever seen deep water or mud.

 

Yeah, it's seen deep water and mud, but nothing lately. I removed the cover and flushed it all out, wasn't much there that I could see, but who knows. Will drive it to work again tomorrow and see if it helped at all. It's the a/c condenser that's the problem, it only starts to overheat if the a/c's on, if the air is off, I can sit in rush hour traffic in 90 degree heat and don't have a problem.

 

I don't know what would be the problem with the condenser. Sure, it gets hot when the a/c is on, but other JK's don't do what yours is doing.

That's why I would prefer to question the engine radiator's efficiency, or its cooling system in general. It seems to be borderline, then the condenser puts it over the top.

 

Have you checked for codes ?? and have any dings coming on

 

No dings or lights come on, had the a/c on early this year as well as last summer and never had a problem. Stopped by a dealership on the way home and they had no clue as to what the problem could be and didn't have time to look at it before closing. Guess I'll have to make an appt to have them check it out

 

make sure the fan goes from low to high speed... when the jeep starts to get warmer the fan should go from the normal low speed up to high.. (you usually will know it because it really is humming out there on high)...

it may just be hot enough that low speed cant handle the heat load of the air-cond and the engine in traffic...

the air cond gets the air before the radiator so if the fan is coming on low it will keep the condenser cool enough to have decent A/C performance....

the dealer should also be able to test low / hi radiator fan operation

-Christopher