When I was on the way home from picking up my sisters from school, I noticed that my coolant meter, was reading "---" and my fan was on full blast. No overheating CEL was on or anything. Any ideas what could be wrong or should I just get the shotgun and take the car out back behind the barn and well you know what comes next

 

Did it stay like that or did it return to normal?

 

The Same Thing Happened To Mine A Couple Of Months Ago But After Sitting Over Night It Went Back To Normal And Has Not Happened Again. Hope This Helps.

 

I haven't checked I guess I'll go outside and check it out

 

What did you find out?? My Cobalt has done the same thing 3 times in the past year. The first time it happened I took it to the dealer....they replaced the thermostat. The second time (around Christmas) they just reset the computer. It just did it again tonight on my way home from work.

 

I think the fans are controled by the PCM and if it doesnt get asignal from the BCM which the coolant temp sensor is wired to it default to the fans being on for engine preservation
just incase.
I would check the coolant sensor connection .
Other wise it could be either P or BCM module is going out.

 

Yeah that happend to me to about 6 months ago, and hasen't happend again.

 

TAKE A LOOK -------> https://www.cobaltss.net/forums/show...hlight=COOLANT

 

I saw that thread. Mine was told to be a bad thermo as well. Whether or not the dealership changed it or not?? It will go back next week, but I am definately putting a dab of grease on the thermo housing bolts to make sure they DO in fact change it.

 

I'm having the same problem with my car.. i have had the ECM replaced and coolant temp sensor replaced and i still have the same problem. I told them to try and replace the thermostat but they dont think thats the problem.. I know theres a new ecm calibration for the 2.2 regarding this issue, any of you tech's out there see anything for the 2.4? The CEL that comes with this problem is p0128.... i've noticed most of us with the prob have intakes, that shouldn't have anything to do with it could it?

Anyone know where the thermostat is in our cars? So that i can take a look at it? I'm getting really tired of going to the dealership every week.

 

anyone?

 

Check under your underhood fuse box, I found mine had corrosion under the fan1 relay and circuit board damage.... dealer says they are on back order and cost $750 cdn