I have a 2002 Nissan Maxima SE 190k while driving the car heats up only when the A/C is running. I have done some basic trouble shooting with no help can anyone guide me in the right direction or advise on what other things i need to do. Thank you for your help.

What I have done so far.

• Checked radiator fluids
• Replaced Radiator Cap
• Checked for leaks in hoses
• left car on for 1 hour without a/c being on (car did not over heat)

 

Are both fans kicking on when you turn on the a/c? Its also possible with such high mileage that you have deposit/scale buildup inside your radiator restricting the coolant flow, and when the a/c is turned on the radiator is unable to cool properly. I would do a proper radiator flush. Prestone does make radiator coolant flush cleaner, follow the directions exactly. I've used it before a few times and it works good.

 

Burp the system first. That doesn't work then check to see if the thermostat is working properly, and replace anyway when you do a flush/fill. Still not working? Then could be a clog or waterpump.

 

the radiator was replaced at 140k so i am pretty sure it is not that. and yes both fans are on

 

These are all good possible causes, but I ruled them out, at first, due to the fact that it only happens with the a/c on, and the car was ran for one hour and didn't overheat. The good thing about a thermostat is they're inexpensive, so it probably wouldn't hurt to change it anyways whether the current one is defective or not.

 

so go ahead and change the thermostat?