Coolant temperature sensor

Tiny
SAMMS21
  • 2007 CHEVROLET COBALT

Engine Cooling problem 4 cyl Front Wheel Drive Automatic

I have a 2007 Chevy cobalt LS with a 2.2 liter ecotec engine, I am having problems with the coolant temperature sensor. I have replaced the sensor twice already and it continues to act up. It will not read when the outside temperature is below 60 degrees Fahrenheit. If I start it from a cold start then drive for a few miles it will read up to 170F° then it will hover around 165 to 170 then it will get stuck on a random temperature in between Then it will read followed by the radiator fan coming on and running constantly. After all of this happens the engine light will come on after a few more miles. Can someone please help me?

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Thursday, September 30th, 2010 AT 8:18 PM

16 Replies

Tiny
BLUELIGHTNIN6
  • EXPERT
  • 16,965 POSTS

This sounds like a stuck thermostat so I will give you instructions on both. Here is a guide for the sensor that will give you and idea on what you are in for when doing the job.

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

and

https://www.2carpros.com/articles/replace-thermostat

Here is the sensor on Amazon for $9.00 AC Delco

https://www.amazon.com/gp/product/B000CGM9O2/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B000CGM9O2&linkId=805f03af74e6b9da40a401896cac12a2

and the thermostat for $18.00

https://www.amazon.com/gp/product/B000IYT1NK/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B000IYT1NK&linkId=d30fab6bff064f6635c722f18549eae0

Here are some diagrams to help you get the job done on your car (below)

Please let us know what you find.

Cheers

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Thursday, September 30th, 2010 AT 8:21 PM
Tiny
SAMMS21
  • MEMBER

I thought I just purchased a faulty sensor but it continued with the same problem

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Thursday, September 30th, 2010 AT 8:35 PM
Tiny
BLUELIGHTNIN6
  • EXPERT
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What type of coolant are you using in system or has it ever been replaced?

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Thursday, September 30th, 2010 AT 8:51 PM
Tiny
SAMMS21
  • MEMBER

Coolant has never been replaced, it is the factory orange colored dextron

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Thursday, September 30th, 2010 AT 8:53 PM
Tiny
BLUELIGHTNIN6
  • EXPERT
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Did more research and it seems to be a common issue with these Cobalts, although I am not finding a solution, however I have found that replacing the coolant sensor and replacing the computer has NOT fixed the issue in the past. Replacing the thermostat is what I am leaning towards, the tstat is around 20 bucks new and rather simple to replace.

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Thursday, September 30th, 2010 AT 9:03 PM
Tiny
SAMMS21
  • MEMBER

Thank you for your help even if the thermostat is not the problem I am willing to risk 20 dollars.

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Thursday, September 30th, 2010 AT 9:13 PM
Tiny
BLUELIGHTNIN6
  • EXPERT
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Yes, normally I don't throw stuff out there but the engine coolant reading is fairly simple set up and from all the research I read online and from what you have described it really leans me to the tstat. Let me know how it goes and if you need steps on replacing the tstat I can get those as well

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Thursday, September 30th, 2010 AT 9:15 PM
Tiny
SAMMS21
  • MEMBER

Not exactly sure where the thermostat is on my car until I noticed the diagram you gave. I was once told to follow the upper radiator hose and it should be at the end of that.

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Thursday, September 30th, 2010 AT 9:28 PM
Tiny
BLUELIGHTNIN6
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The thermostat is located behind the engine under the exaust manifold on the drivers side. Just look for the water pump tube and you will find it.

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Thursday, September 30th, 2010 AT 9:31 PM
Tiny
SAMMS21
  • MEMBER

Is eat easy to replace? Just unbolt and put the new one in or is it more complicated.

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Thursday, September 30th, 2010 AT 9:34 PM
Tiny
BLUELIGHTNIN6
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Thats the jist of it , getting to it is the ...not really the hard part but the time consuming part. here are some instructions to help ..

Removing the intake manifold cover:

Remove the engine oil fill cap.
Grasp the intake manifold cover by the lower right inboard corner and pull up to disengage the cover from the stud.
Grasp the intake manifold cover by the upper left corner and pull up to disengage the cover from the stud.
Remove the intake manifold cover.

Drain the cooling system.
Reposition the radiator outlet hose clamp at the thermostat cover.
Remove the radiator outlet hose from the thermostat cover.
Reposition the radiator surge tank outlet hose clamp at the thermostat cover.
Remove the radiator surge tank outlet hose from the thermostat cover.
Reposition the radiator outlet hose clamp (1) at the thermostat cover.
Remove the radiator outlet hose from the thermostat cover.
Remove the thermostat cover bolts and cover.
Remove the thermostat.
Remove and discard the thermostat cover O-ring seal.


http://www.2carpros.com/forum/automotive_pictures/261618_1_199.jpg



http://www.2carpros.com/forum/automotive_pictures/261618_2_129.jpg

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Thursday, September 30th, 2010 AT 9:36 PM
Tiny
SAMMS21
  • MEMBER

Thanks you the thermostat seemed to do the trick it is all fixed, thanks a million guys, this site rocks.

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Thursday, September 30th, 2010 AT 9:43 PM
Tiny
BLUELIGHTNIN6
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Glad we got it fixed we like this site too :)

please use 2CarPros anytime we are here to help.

Cheers.

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Thursday, September 30th, 2010 AT 9:49 PM
Tiny
BABYCODY3
  • MEMBER

It fixed my problem too, thanks guys.

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Tuesday, December 2nd, 2014 AT 6:37 PM
Tiny
MARCANTEL_1
  • 2007 CHEVROLET COBALT
  • 107,000 MILES

Changed coolant sensor, didn't help changed radiator hose, still didn't help. Also unhook battery cable to reset only work for 1 day. Any suggestions?

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Thursday, September 7th, 2017 AT 2:51 PM (Merged)
Tiny
RASMATAZ
  • MEMBER

What exactly is the code no?

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Thursday, September 7th, 2017 AT 2:51 PM (Merged)

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