My 2008 hhr ss overheats , I changed thermostat it makes a loud whirring noise when I accelerate/push on the gas. Looking for suggestions on what it could be. Thanks

 

Welcome to the site, when you changed the thermostat, did you burp any air out?
Did you install an AC Delco 131-158 180 degree thermostat?
Did you drain the radiator and refill with 50/50 Dexcool and water?

 

What does "overheating" mean? What temperature.
Is the whirring sound different from the turbo kicking in? Are you ignoring any warning lights on the dashboard?
"Could be" a RC Cola cap stuck in the alternator. "Could be" a plastic bag blocking the radiator
Is the fan running? Sounds like either the fan or the PWM module for it went bad. Maybe the water pump.
The t-stat works to keep the temp ABOVE 180F, it does not cause overheating, the radiator and fan control the high end.
If the temp gets over 230F immediately park the car, there is big danger of major damage.

 

I have a 2008 zzp edition HHR SS. It’s overheating and makes a loud whirring noise when you step on the throttle. I was told it’s pbly just an air pocket in my coolant system , but I figured I’d get a second opinion just in case. I’ve already changed the thermostat twice with no change in the problem. Please help me with this, I love my car and need it on the road where it belongs lol

 

What drove you to change out the thermostat? Did you burp the system well? Sounds like air.

 

I can think of 2 things that whirrrrr, when not moving The turbo and the water pump. Both of those cold cause heating.
What does overheating mean in numbers?
Have you observed the cooling fan?
If you suspect an air bubble; where did the water go? Is the coolant low? Did you check it under the pressure cap and the recovery tank?
Do you hear a burbling sound in the waterfall? That would indicate low coolant level.
Any codes being ignored? Don't be offended we have heard twice this month "the CheckEngineLight has been on for a year".
For future use: T-stats don't cause overheating. Their job is to keep the temp above 180F, the fan and radiator do the cooling.

I never heard of a ZZP Edition.

 

The noise could be the balance shaft chain over tensioned. Is it possible you post a video? Of course after you burp the coolant.

 

Matstone1.
You ask this same question about a month ago. You never came back to that thread where Donbrew gave you some info and ask you for some details.
No need for you to start another thread about the same issue.

 

Merged.

 

Now let’s see if he returns and posts anything