[Bob12312357]

Hello, my 2007 Pilot overheats. The radiator and aux fan won't come on while the car is running. When I shut the car off the fan comes on until the engine is cooler down so they work. Any ideas of what would be causing this weird issue. Also ac obviously isn't working as the fan isn't coming on.

 

[plplplpl]

Time for a new thermostat?

But check all your fuses and relays first. Use a multimeter and/or swap in known good ones.

 

[road2cycle]

Got enough coolant in the cooling system? Perhaps there is an air bubble trapped near the coolant temperature sensor. Make sure the engine is cold before you check. Add coolant and burp the trapped air out if necessary.

Also do a search on google or YouTube for a tutorial on how to check if your thermostat is stuck opened or closed.

 

[Bob12312357]

Would the thermostat issue cause the fan to not turn on when running, then turn on the second it shuts off. Fuses are good.

 

[road2cycle]

More than likely not, unless turning the engine off is causing an air bubble to move around the coolant temperature sensor. It takes 10-15 minutes to check. Removal of thermostat isn’t required.

You might also check/test your fan relays to verify they aren’t sticking.

And welcome to the forum.

 

[huntertn]

The system is a little complicated. There are temperature sensors/switches that activate a different temperatures. There are relays for each fan and there is a fan control module.

There is a step by step troubleshooting guide in the factory service manual. If I had this problem I would follow the troubleshooting guide because anything else would just be guessing. I doubt it is the thermostat.

 

[plplplpl]

^+1

Here's the section from the service manual for fan troubleshooting.