Timewalker

Hey all, I'm back again.

So as the title states, my 08 is overheating. Driving back from grocery shopping yesterday and the warning light came on, temp gauge was in the red. I immediately cranked the heat like my older brother told me to do until I found a safe place to pull over. I let it cool down and then drove the couple of miles home, with the heater blasting and it got back to 245 degrees.
After cooling down, I added some Dexcool 50/50 to the overflow tank. Started it again and a drive down the county road got it back up to 250, so that wasn't the (only) issue.
The fan is working. (check)
There is no sign of water/coolant on the dip stick (yay!).
I can't find my code reader so I need to get the bluetooth dongle off my wife's car when she gets home and see what code the light might have logged.

I searched the forum and found this thread and tried the "follow the flow" technique - https://www.chevyhhr.net/forums/prob...e3/#post733927

The upper hose is hot. The lower hose to the thermostat is cold and so is the radiator.
So, what does this mean? Clogged radiator? Busted thermostat?
Thanks.

donbrew

After it cools down look under the pressure cap, coolant should bee up to the filler.
Does the heater work?
Doubtfully a bad t-stat. They usually fail open. If you replace it use ONLY ACDelco part number 131-158 not "replaces, fits,, like etc"
Could be obstructed heater core or radiator or a bad pump.

Oldblue

Or a bad balance shaft chain.

Timewalker

No coolant visible when i take off the cap (except for drops of condensate).
Yes, the heater blows hot air.
Thanks.

firemangeorge

So you have a leak somewhere. Fix that and then hope you didn’t damage anything (head, head gasket) with the excessive heat.

donbrew

Go get 2 gallons of 50/50 DexCool any brand you like.
No matter what you read the level on the overflow tank is not reliable, and filling there does not help if the pressure cap isn't working right.

Oldblue

Burping is important!

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


The cooling system

Timewalker

Thanks guys. I added about half a gallon until I could see it at the fill opening. Test drove it and it stayed between 190-205. Then it was getting dark. I will check it tomorrow, look for leaks, feel the hoses, add more, burp it, repeat, etc.

PulpFriction

Was the coolant recovery tank completely empty or just low?

donbrew

Mine was leaking steam through a crack in the plug on the t-stat housing. Didn't leave a puddle or other evidence.