My daughter reports that the engine keeps running -but it's just the fan. Thinking that it's because the engine was hot and this was normal, I went out this morning after a cold night on the driveway and started the HHR - and immediately turned it off.

The fan was indeed continuing to run, with a stone cold engine. It ran for an astonishing 7 minutes before turning off.

Other than this, the car runs fine, doesn't overheat or seem to act unusual in any way.

Local part store recommended I change the ECT sensor.. but can't even find it, or any documentation on where it is. Nothing on youtube that I could find either. Makes me think it's not a common issue!

Any ideas?

VIN: xxxxxxxxxxxxxxxxxxxxxxxx

 

Welcome to the site.

Stating the year model and engine size would be helpful.
Also. Don't know what you mean by ECT sensor.

Need to post up this info and we'll see if we can help out.

(not sure why you put up your VIN. In this day and age of electronic theft, that may not be wise to post it in an open forum)

 

Welcome to the site! This might sound crazy but HHR's have their quirks! Check the rad fluid , cold at the filler cap on the upper rad hose

 

I assume ECT is engine coolant temperature sensor. Check what the coolant temperature is in the display as that is likely the input the computer uses. I'm assuming that the computer controls the fan via a relay.

 

Yes the ECT sensor is that Engine Coolant Temperature and so with the possibility of an air pocket it could cause the problem. When I replaced my t-stat last year, I removed my ECT sensor cleaned the threads and used sensor save Teflon tape

 

Thanks firemangeorge. I honestly dont know the engine size and hoped the vin may help instead to you experts. I'll track down the docs when I get home.

 

Yes ECT is coolant temperature sensor. What confuses me is that something is obviously telling the fans that the engine is hot when it's stone cold. That would be the opposite of an air pocket I'd guess - where it would remain thinking it was cold when the engine was hot?

The engine was run for 10 seconds after a night out, so there was no temp registering on the dash. The engine was completely cold. Yet, something was telling the fan to run for 7 minutes with the key removed.. and it happens every time

 

P.S. The car is 2007 LT 2WD 4DR Auto - but I don't have a single piece of paper that shows the engine size!

 

Since you did X out the VIN, try this link for your engine size( and other decodes)-------
https://service.gm.com/dealerworld/vincards/

Fwiw. Did you check the fluid level as suggested above ? The temperature gauge should register at startup even when cold(the digital gauge in the information center or DIC ) The analog or needle gauge probably won't show anything when cold.
If the digital gauge shows lines like ----, you may have a bad temp sensor or even a bad thermostat. You should probably have the codes pulled and see if there are any CEL codes (check engine light).
CEL's don't always come up on the dash and are sometimes stored in the computers memory.

If you get the codes read, post up any code numbers here. Don't post up any code descriptions because they can sometimes be wrong. Just post up any actual code numbers.

 

Thanks again firemangeorge - 2.2L it is :)