Hi all I have a 2003 CL type S, with 120K miles on it and the temp was getting really hot while running the AC and sitting in traffic. I replaced Thermostat over the weekend and when I started the car the needle laid on the peg below C for about 5 minutes then jumped up to about half way (normal range) then the first time I stopped while driving with AC running temp started climbing. When I hit interstate car cooled off, or when I killed AC it cooled off.
Could there be a problem with the thermostat? It seems weird the temp gauge laid there at bottom then suddenly jumped up, having never done this with old thermostat...
Also any other possible easy fixes for temp? Radiator Cap? Coolant flush?
Which fans are supposed to be running with AC on?

thanks a million!!

 

Does the temp go into "overheat" or just higher in "normal" with the ac on?

 

does your fans kick in? it might be as simple as fan switch

 

had same problem with my 01 had to replace my coolinf fan motor, it worked whn it wanted to. Good luck

 

It could be the fan but I had a similar problem a couple years back and it was a leak in one of my hoses that go to the radiator and since the coolant leaked out it was causing my engine to overheat.

 

check the hose going to a resere tank ? mine was loose and car was overheating