Overheating (customer car)

Not used to working on DSM's, so I thought you could all lend me a hand. I have a customer who brought in his Gen 1 eagle talon AWD turbo in for overheating. Pressure built up and blew the upper hose radiator neck off. Installed a new radiator and it still overheats. Took out the thermostat, still overheats. I realized that the fans were not turning on. They do turn on when the ac is on. Temp gauge on the dash is working.

Any ideas? Thank you for your assistance.

your main fan is not working properly. 1 fan turns on with the AC, iirc, it is the passsenger side fan. If the other fan doesn't turn on at all, I believe it should turn on at 210 degrees, then either replace the fan, the wiring, or the switch it connects to

Blown head gasket

If neither of the fans work (like crunchy said they only come on at higher temps) that would be it if the car starts to get hot get out and check if the fans are on. A cheap fix is to bypass the thermo switch and have the fans run all the time.

Does the car still blow the radiator hoses? Does it blow cool or warm air out of the heater?

Blown head gasket


Check the fans first. No fans = automatic overheating = boiling = pressure

I turn the car off before it has the opportunity to blow the hoses. Car blows hot air, so there aren't any air pockets in the heater core. Both fans turn on with the ac on. Neither are activated when car is overheating.

Both fans turn on with the ac on.


Does it still overheat when you keep the ac on?

Also have you checked to make sure the fluid is circulating?( I know you said it blows WARM air but just a thought thats all)? Is both upper and lower hoses hot or have pressure on them?

so the car builds up alot of pressure fast?

The coolant is circulating, we can see it moving in thee reservoir. The car doesn't build up pressure too fast. Takes about 15 minutes to come to the middle of the temp guage. Heat blows hot. Switched the foglight and the fan relays to check if the relay could be bad. Fans still not turning on automatically. I ran the car until the temp gauge hit the red. The fans will turn on when ac is acvtivated.

Thanks again for all of your help.

im assuming you checked the obvious things first...... coolant, what shape the oil is in (hopefully not like chocolate milk).

Oil is nice and fresh.

have you verified its overheating and not just a faulty gauge and or sender/sensor?

Okay, the driver side fan turns on when I turn on the AC and the passenger side fan turns on when my car runs towards hot. Thought I would add my two cents.

The coolant is circulating, we can see it moving in thee reservoir.

The coolant shouldn't be moving the resirvor, all that is is an overflow tank and the coolant shouldn't technically be "moving" around at all. I'd fill the car up with coolant (the radiator, not overflow resirvoir) and then check the thermostat and temp gauge sender. If all those check out good then you're into much bigger problems.