2007 Chevy Cobalt coolant temperature sensor

Tiny
SAMMS21
  • 2007 CHEVROLET COBALT

Engine Cooling problem
2007 Chevy Cobalt 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 170FÂ ° then it will hover around 165 to 170 then it will get stuck on a random temperature in between Then it will read ---FÂ ° 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

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Tiny
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When you replaced the sensor both times did it ever fix the issue?

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Thursday, September 30th, 2010 AT 8:21 PM
Tiny
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No it never fixed the problem 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
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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
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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
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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
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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
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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
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Not exactly sure where the thermostat is on my car 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
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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
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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
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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
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Is there a drain plug at the bottom of the radiator? On the radiator overflow bottle cap it says there is a special drain and fill procedure for the coolant

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Thursday, September 30th, 2010 AT 9:43 PM
Tiny
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Nah we just need to get that coolant lower than the thermostat, if you were draining the entire engine assembly then there are few special steps but for this repair you just remove the surge tank (coolant resevoir) cap and then open the drain cock of the radiator, it should be on the lower right (passenger) side of the radiator, on the motor side of the radiator. Just loosen it until coolant comes out, don't have to remove completely.

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Thursday, September 30th, 2010 AT 9:49 PM
Tiny
BABYCODY3
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I was wondering did this fixed the issue replacing the thermostat

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Tuesday, December 2nd, 2014 AT 6:37 PM

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