When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Problems/Service/RepairsIf you have a problem with your HHR, want a tip on repairing or performing a particular service to you HHR here is the place to post!
What if’s and what could it bes are all philosophical, it’s the black rubber oring in the OEM stay it has deteriorated and jammed the thermostat open .
It’s the Cali ambient air temperature helping get the heat into the rad ands engine.
You might consider changing the Dexcool while your at it and have your hands dirty, especially if it’s more then five years old.
If the computer doesn't see a temperature it turns the a/c off in the hope the oblivious driver notices there is a problem.
In this case I am thinking the sensor, since you say there is never a reading and there are no pending codes. It is easy enough to inspect the t-stat to see if the rubber slipped off and is jamming the valve open.
I am still not sure if it's the sensor or the thermostat but here are my new developments:
I ended up pulling use #41 for the ecm. It was a lot easier than emptying my trunk and tray to get to the big fuse. Left it pulled out for 45 minutes. Put it back, turned the key and no temp. So I left work, battled through the surface streets and joined the freeway stop and go hell. About 15 minutes into my trip the temp reading came back showing 190F with 81F ambient temperature. We were kinda moving and it stayed between 190 and 200. After I got off the freeway with 81F ambient still the temp started to rise and settled between 208 and 199 it seemed to rise fairly quickly every time I had to stop at the light so it made me think. I tried to raise the rpm for a few seconds while I was waiting to see what it does and it actually dropped the temp. Even when the ambient went up to 97F it was still doing the same with the same numbers. So I think what happened is the thermostat was stuck partially open and didn't really move. So the engine was relatively slow to get up to temp and then it got hot when it was idling due to not enough coolant flow. But me revving the engine helped.
Then I pulled into a drive through to get dinner. The temp rose to 208 again as I was ordering then all of a sudden it dropped to 198 in about 2 seconds. After that it did not go over 199 and when I left it quickly dropped to 190. So most likely it got unstuck.
Despite it working now I will pull the thermostat this weekend. This will come back if I don't replace it and it will come back the worst possible time. And then we'll see if it fixes this problem or I end up having to replace the sensor as well. I could do both but now I want to know what caused it.
What is this fuse pulling stuff? The maxi fuse near the battery is for the BCM only. If you are trying to reset the computers disconnect the negatice post of the battery.
That description is sounding like either low coolant level or an air bubble.
I found it under the link whopper posted. But I pulled the ecm fuse.
I checked the coolant level which was low in the reservoir but pulled the radiator cap also and it was full with no air.
Either way I will replace the thermostat. The PO neglected all maintenance on this car so this might be the result of that.
Note the gap where the light goes through. I think that was a minor problem that was going to grow into a bigger one.
On the back side it's clearly visible how the rubber started to come out. Interestingly it didn't feel like it was deteriorating. It was just torn and started to slide out of place.
This picture is more interesting. You can see the shiny spot on the copper chamber that holds the gas. it was rubbing on the housing. I wonder if it got stuck there.
The new one I got from the dealer. After taxes it was $81!! But it came with a 5 year warranty.
Turns out the one that was in my car was an aftermarket one with STC stamped on it. It was also installed wrong. The seal was put under the thermostat instead of over the edge like in the next picture. So I most likely had a small leak there. I was loosing coolant slowly so now I'll see if it stops.
BTW The GM one looks a bit more robust and the rubber seal on the valve is a lot smaller.
This morning everything looked fine. The engine seemed to run cooler than before but the real test will come on my way home.
Thank you very much for all the help!!! The guys who know what they are talking about got it right again.
Glad it's working for you, that old one was certainly a problem. $81 OUCH!! I think I'm gonna order one now, just to have it. 20% off coupon right now on Amazon, comes to about $32, w/free shipping.
That is the aforementioned inner rubber gasket that always fails on the wrong t-stat!
The 131-158 is metal to metal, no point of failure.
I wish people would start listening to us "old farts".
The t-stat has nothing to do with the motor running cooler; as I have tried to make clear it's job is to keep the temp ABOVE 180F and to get it there QUICKLY from a cold start.
You’re welcome, ( I so want to say, “Told Ya”) but yupp it was the thermostat! Glad you listened and found that gasket issue and the flap problem and the rubbing shiny copper thingy.
Now, go forth and enjoy the ride!
06-08-2018, 07:36 PM
