trentonwayne

Its really cold here in MN, and yet, 3 minutes after turning on my icey cold car in the frigid cold, my radiator fan turns on. WHY? It never used to do it. The fan would usually never turn on, even in the summer. Why all the sudden the change. 2006 SS 2.4 Auto 130k

calo247

do you have it on front window defog, that will kick on the AC and that will turn on the fans to try to get rid of the moisture on the window through the AC condenser, i know it sounds backwards that the AC runs when on heat but it is used to dry the air out, and it wont turn the light on the AC button either (at least on my SS/SC). so try leaving it to just blowing at your feet or something and see if it does it.

it could also be a bad coolant temp sensor as that would cause the fans to kick on when they should not

also try swapping out the relays on the fans, would be weird for them to act up after 3 mins but i have seen weirder things in my job as an electrician, i believe there is some identical relays for something else that is less important, rear defog rings a bell i think but dont quote me on that

it would be really weird but i suppose it could also be an air bubble stuck in the coolant line right around your coolant temp sensor, air has a lower heat capacity than water and would heat up quicker causing a bad reading on the sensor, so i guess you could check the coolant level and make sure there is no air in the system but that would be doubtfull

Snail_SS

iTrader: (3)

Yeah i remember hearing something about the a/c working while on defrost so that might be it. If not make sure you have coolant temp readings on your dash if you dont then thermostat if that doesnt fix it then maybe your temp sensor going bad

Spawne32

iTrader: (1)

Well the AC is supposed to work with the defroster on, because the AC system is a dehumidifier and thats what allows the defroster to work. Don't know if all of the cobalt's turn the AC on on the defrost setting, pretty sure mine doesn't, but that would be a reason for the fan to turn on.

toolman

The AC (and thus the radiator fan) will also turn on if you have the knob turned to the full floor setting.

TurboTechRacing

iTrader: (24)

Yup, A/C on, to help defrost, which turns on the fan. 100% normal.

Spawne32

iTrader: (1)

Why would it turn on if you have it on the floor setting? lol I've never experienced that.

toolman

Maybe to dry your wet shoes? I'm not exactly sure why it is designed to do that.

Pushing the recirc button will also turn the AC on.

Spawne32

iTrader: (1)

What year car? It doesnt do that on my 06 or my 08.

toolman

2007. The AC light doesn't come on, but you'll hear the compressor engage, and the air will start drying out in the car.

trentonwayne

Thanks guys for your replies, tried it with the floor setting and it didnt turn on, used the defrost and it did. Just weird, i didnt even realize the fan was on, i bought the car new in 2006, thats a long time to not notice that...... haha

Spawne32

iTrader: (1)

that is a long time to not notice that cus these fans are loud lol

trentonwayne

Same problem still going on. Anybody know what else could cause this from happening? Water pump failing? It stays at 190 degrees when im driving above 55. It climbs to 198 when im driving casually. Also, the fan turns on and off every 10 seconds during a 15 minute drive of casualness. Normal weather here.

cobaltss#01

iTrader: (4)

if there isn't a CEL I wouldn't worry about it. Mine. comes on at 194*. Matt has it set in the tune that way.