Leemor

Hi all -

So the wife says "Oh, there was a warning light on in the car..." I want to know more details: "did you stop or keep driving? which light was it? what did the other gauges say?" Of course details were scarce... Well except the part about not stopping and driving on home. She was pretty clear on that.

So here's what I know:

1. The check engine light is on steady
2. The temperature gauge stays flat - shows no heat at all (Luckily the car was still hot when the wife told me about the light - I immediately went out and started it and checked gauges)
3. Coolant temp displays three hyphens (---) instead of numbers
4. No evidence of coolant leak (puddles / splatters) but coolant overflow tank appears empty
5. Radiator was replaced a few months ago after being punctured - I took the dealer's word on the diagnosis and paid out of warranty
6. 2007 HHR LT 2.4 liter

When the radiator was punctured before, the temp gauge shot way up and the coolant temp went into the 230's. This time, the flat gauge and three hyphens have me confused.

I'm taking it into the dealer tomorrow but want to be somewhat more knowledgeable about the possibilities. Do you think I have another punctured radiator? What are the odds?

Any ideas? Thanks a million.
Leemor

masterchief1112

im going to guess a bad sending unit. not another punctured radiator.

Leemor

Thanks Masterchief. I much prefer that theory.

blkhhr06

its the thermostat mine done the same thing

esmarkey

A bad thermostat isn't going to give no reading at all, I agree with masterchief, bad sensor. Even if the fluid was low, should read something....

blkhhr06

well mine was doing the same thing and i went and got the sensor changed out and that didnt help so i changed out the thermostat so far its doing good everything is reading.

HHorange

It's a bad thermostat........It is very typical with the HHR and yes when it doesn't come up to temp fast enough Both temp indications are shut down by the computer.....Been there done that!

esmarkey

Well, I guess you can teach an old dog new tricks....
I really strugle with the "computer" taking over so many functions like gages.
But then again, I am still looking for my door chime so I can remove it

Leemor

Thanks all. You saved me a tow. Confident that it was just a thermostat or sensor, I drove it on in to the dealer. I'll let you know the final diagnosis.

whopper

Yup, bad thermostat. It actually was kinda fun to watch it drop off the display ("- - -") by switching the display to the temp reading as the car was first warmed up. You could see it rise to the low to mid-80 deg C. mark - then the display would switch to the "- - -" if it did not get to a high enough temperature after a certain amount of driving. And much depended on the ambient air temp as to when the display would disappear - the colder it was outside, the sooner it would disappear and the Engine Check light would come on. If it was really cold outside (freezing) the display would disappear as soon as the car was started.

It was resetable, by disconnecting the battery in the trunk for a couple of minutes, and the display would then come back on and the Engine Check light would go out.

Another symptom related to a bad thermostat, is that the A/C would also be disabled on occassion - would not happen every time, but the computer mush have some sort of programming in it where it shuts down the A/C if the temp is way too low for an extended period of time.

I ended up replacing the thermostat myself, after the dealer wanted in the neighbourhood of $350 to replace mine. Sure it is buried down on the backside of the engine on the drivers side, and is a bit awkward to get at, but $350??? Sorry, no way.