so last night friends and i installed a new alternator, the car started fine ran for 10mins no problems i even drove it home. on the way home the abs light come on for a few seconds then went off i hit the brakes and they worked. got it home and hour later went to started it and nothing just clicked tried to jump it, nothing just clicked. so i charged the battery all night and day. put the bat. back in went to start the car and click click, then turned over.

so i went through the DIC and notice that the fans turned on when i turned the key and i have no eng. temp readings?? what could be the problem and now i have a CEL???? so lost HELP. lol

 

The Solution: Sell Sell Sell!!

Coolant Sensor/Thermostat took a ****. The car thinks its over heating causing the fans to turn on. I had this issue. But I cant figure how your alt swap could have fried it

 

lol no its "hey look i see a cliff, can someone help me push!"

 

Did the warranty expire?

 

yup!!! lol like 50,XXX miles ago lol well damn can anyone show me where in the motor i can find this?

 

Id like to know this as well. Im quite positive the thermostat is causing the fans/temp reading. Have you had the CEL scanned?

 

lol yeah im mad your the only one helping. what a helpful site this is. lol

 

Well the only reason why I am helping is because I know you and have had this issue twice already on my balt.

 

and thank you cause now i know whats the problem is, now i need to find it and how to install it lol. you have done more then most ppl lol so thanks

 

If the thermostat fails and gets stuck open, coolant is rapidly circulating. Thus causing the car to think it is over heating when its really not. Resulting in the fans turning on and the CEL popping. Just be safe with it. For all we know the thermostat is stuck closed. I'm not mechanic so someone needs to speak the **** up lol

 

lol i found something https://www.cobaltss.net/forums/problems-service-maintenance-69/fan-constant-176603/

i thank i might try changing the thermo will it be ok to drive my car i need to get to work lol?

 

ok, well have the code scanned...probably a p0128 popping up I'd guess....the a/c doesn't work either does it?

Now, if the thermostat was stuck closed, the car would over heat....since the coolant wouldn't be able to circulate from the block to the radiator. If it was sticking open slightly, the coolant probably isn't reaching it's operating temperature. Had an HHR that came into the dealership last week had the same problems you are having...there was a small tear in the inner seal on the thermostat letting coolant leak by and not reach proper temps...

First step is to see what the code is that you are throwing.

 

Get Phil to scan it, Chase

 

damn i dont have a code reader and it 11 at night lol the fans stay on??? could that determine if its open or closed?

he doesn't have one

 

If a cooling system related code is set, it will go to default...meaning the fans could stay on, temp. indicator doesn't work, and the a/c is most likley disabled.

 

Isnt it alright to temporarily drive the car assuming the Thermostat is stuck open?

 

well, assuming it's sticking open....you could drive it. Probably run rich or whatever..... I'd get it fixed as soon I could though

 

::FACE PLANT:: im really hating this car!

wheres the sensor located on the car well motor?

 

back of the motor on the drivers side, in the thermostat housing......honestly, doubt the ect is bad....

 

i think it might be a fuse?? whats ur opinion? and thanks for the help sunburst

 

Go to advanced and get it read

 

you need to get the code scanned first......find that out, then go from there.

 

BLOWN FUSE!! i swaped the wiper1 fuse with the cool/sen and i have a coolant reading!!! I WIN BOOO YEAH COBALT 0 CHASE 1!! lol

bad thing is i only have one wiper lol

 

JK still have the problem!!!

 

So after reading a ton about this problem after my project came up with the issue... replaced temp sensor, thermostat ! No change.... then I found this horse **** !



Here you can see, corrosion on the Underhood fuse panel, the spot that is corroded is the fan1 relay...
called dealer they said these fuse boxes are on back order and $750cdn ???? Who designs a fuse box that’s not water tight ???? Good job gm 🤬

im having this repaired today at an electronics shop, will post results !! This is for sure the issue with the temp gauge going away and the fan staying on !