Last October I had my mechanic replace the thermostat in my 2010 HHR. In the past couple of weeks the A/C has started to malfunction again, especially in the hot Texas weather this summer. The A/C sometimes works but usually doesn't, and this morning the COOLING MODE ON message appeared on my dash (see photo) along with the engine light and thermostat light. The fan runs 5 to 10 minutes even after I put the car in park and shut off the engine. Could this be anything other than a malfunctioning thermostat?

2010 HHR dashboard

 

Scan all modules for codes.

 

Do Not Drive The Car !! Do Not even turn it on.
See that little needle on the temperature gauge ? It’s pegged into the red zone. You have overheated the engine.
Engine damage could occur (if it hasn’t already) Call a repair shop and explain it to them. Have it towed if you decide to have it worked on.

FYI . That’s not a thermostat light. It’s the engine coolant warning.

 

The engine is severely overheating!!! don't drive it until it gets fixed.
Do you know that you can see the actual temperature? It is in the Owner Manual, link in my sig.
How long have you been ignoring the CheckRngineLight?
T-stats don't normally cause overheating. There is probably some other issue like no coolant or an obstructed radiator. Have you ever checked the coolant or oil levels?

Greg8453, get real. That stupid suggestion is getting old. No such thing as "scanning all modules" even if the person that doesn't know how to open the hood had a capable computer interface.

 

Looks to me you have either a thermostat stuck closed. Or the balance shaft chain has broken so it can’t turn the water pump. I’m also thinking your mechanic just put any old antifreeze in the cooling system, it really needs to be 50/50 Dexcool and distilled water. Then the cooling system must be burped


https://www.chevyhhr.net/forums/how-...-system-60614/

 

Thanks, everyone, for the advice. I poured 50/50 Dexcool in as a stopgap and drove the HHR to my mechanic. It turned out to be a ruptured radiator, and the t-stat also needs replacing. Not a cheap repair but I'm glad to have it diagnosed and on the way to repair!

 

Hopefully the head isn't warped or some other catastrophic damage, from overheating. And then driving it again?

 

Use an AC Delco 131-158 180 degree thermostat.

 

My guess. A new radiator and thermostat may not be all it needs. It pegged the temp gauge. Then they drove it after being told not to. Very high chance the engine has damage.

 

Quick question: What is the usual temperature for coolant as shown on the dashboard? Are sudden rises and falls normal?