For all these cooling issues the solution is always "thermostat".I changed mine and I'm still overheating unless I turn on the heater. The original question was about the Temp sensor location. It's frustrating when all my searches on Google direct me to links like this that don'tanswer the question asked. Can anyone answer this? Is your problem fixed?

 

The original thread was not about it overheating. It's about the instruments flat-lining due to the thermostat being stuck open, causing the engine to run too cool. Big difference.

Where is the sensor? I'll see if I can find the location for you if you post some details on what engine you have.

In the meantime, what you need to search for here is "overheating". The solution is not always thermostat - it often is just low coolant, or head gasket, or other nasty mechanical causes.

 

Split this off into a new thread, and as whopper suggested, a search on "Overheating" would be more beneficial.

 

Location of Engine Coolant Temperature (ECT) sensor: on backside of engine (exhaust), half hidden behind the thermostat housing, between two upward pointing coolant pipes that are located to the right side of the thermostat housing.

 

Beat me to it whopper, you've got fast fingers mate!

 

Wow! Thanks guys, I hope I don't seem like I want people to solve my problems I search diligently and have scoured the net for my issue. Let me explain. I have a 2006 2.4L LT I was in a minor accident about a month and a half ago. Everything seemed fine until last week my radiator busted in traffic draining all the fluid out. I it apart to find my bumper guard into the condensor and radiator. The condensor was still charged and I bent it back with two boards and C-clamps. I found that the fan had cut the radiator in the center by the shaft. I replaced the radiator. Bent everything back. No leaks. But I will overheat if the heater is not on full blast. I'm in Chicago it's below freezing. How fast I'm going changes nothing except more rpm equals more heat. The fan still works. I just replaced the thermostat. Still same problem. Overheat unless heater is on. If the pump Was bad I'm thinking the heater wouldn't work. So maybe the sensor? Thanks again for the info. You guys rock and sorry about my frustration this morning. 3 hours of Google and I'm a Software engineering student, well versed in search, but kept reading the same answers

 

this may be a simple issue of the rad not fully burped of air, just thinking here, as you did mention the rad being replaced, I found if you park the HHR with the right front corner higher and run the engine till warmed up, then park it like I said let it cool off and check the rad hose fill, if there is room top it up with coolant.
You also stated that the fan was an issue is it working?
I know this frustration, I had it 3 years ago when the issue was the head gasket and again this last fall when it was the t-stat

 

You could simply have air in the system...

 

beat you badassbowtie! well a tie same clock time for the posts!

 

I've got to agree. Sounds like air in the cooling system.

If it was OK heatwise before the accident, it would seem logical that the repair work would be the culprit.

These little cars can be tricky when it comes to getting the air completely out. Oldblue has some good advice as far as elevating the front corner.

And don't fret if that's all that's wrong. You won't be the first one that has had this issue.

Questgraves. As a side note: Do you hear any gurgling noise coming from the heater core area? Previous posters have stated hearing that noise, then finding out the coolant level was low. Result: air in the system.