Hello,

I have a 2009 Suburban 1500 LTZ w/ 5.3 V8... engine is overheating. Cooling fans turn on when driving but will cut out when idling. Also, if I cold start vehicle and let it heat up, cooling fans do not kick on. A/C goes from recirculated to outside air. I have already changed thermostat and coolant temperature sensor... checked fans with wires leading from battery to fan motor connectors and they do not turn on... So, question (1) is could this be a sign of failing fans? if so, (2) Replacing the fans requires knowing whether or not you have enhanced cooling, anyway of telling me how I can figure this out? Thanks for any insight anyone can offer me.

 

Look on your glovebox sticker for the RPO codes below, or just look through your grille.

 

Your initial description said the fans run while driving - I doubt they would both fail at the same time and/or run intermittent. Don't think you have found your main problem yet. Any codes to go by?
What is your gauge reading? Which sensor did you change?

 

Rednucleus thanks,
No engine codes... Replaced engine coolant sensor... Is there another sensor i could try changing? Thanks for replying

 

Intheburbs Thanks for replying,
Dealership where I bought car was no help in figuring this out... they could only tell me what fan I had.

 

There's a sensor for your gauge (probably down on the block) and one for your computer (top of the motor?) What is your gauge reading on your dash?