see post #37 https://www.chevyhhr.net/forums/gene...r-12317/page4/

I don't know what eighth digit "d" means. The choices are X, F, B. That VIN is not for an HHR. It should be something like 3GNA125F?8SXXXXX

Now, what do you think is "overheating"?

 

Yep, I would agree with George. Your thermostat housing was cracked(for who knows how long), causing the engine to overheat, causing a problem with the head-to-block seal. Head gasket/cracked or warped head/cracked block.

 

Thanks for the corrections all I'm a plumber not a car mechanic, they were supposed to check for any heat damage when they did the ECM diagnostic at dealership to see If head gasket was gone, supposedly its not... course they followed up with it's just overheating because fan doesn't go into "high mode" and since it's a 2.2 LS they were innaccurate? That radiator fan is either on or off? And should it be kicking on the second the cars on and staying on?

I've had enough situations with boilers where idiots jump out safety devices to know it happens that they just jump it to always on and etc...

 

One more time:

The t-stats job is to keep the temp ABOVE 180F
The t-stat opens at 180F to allow the coolant to circulate
The radiators job is to keep the temp below 210F
The fans job is to keep the temp below 219F.

The cycle goes:
warm up in about 3 minutes to 180F, t-stat opens.
temp while moving should stay right around 190F
The fan comes on at 219F and stays on until the temp is down to !80F (where the t-stat should close)

If the AC compressor is running the fan is supposed to be always on, this includes when Defrost mode or recirculate are chosen.

It is not unusual for the temp to get up to 219F while idling, then the fan should come on until the temp is down to about 179F

It sounds like someone thought they were smarter than the GM engineers. I don't know what they might have done. There is absolutely NO excuse for replacing the ECM for this complaint and not many others.

There is a fan relay in the under hood fuse box; it may be malfunctioning. The shop manual does claim there is a 2 speed fan, but that was written before production began (gee, imagine me giving a mechanic an out).

The ONLY t-stat that should be used is a ACDelco 131-158. ONLY a 50-50 mix of DexCool for coolant.

 

Thanks Don a order of operations helps I can usually follow those, how do you tell when tstat opens/closes? Voltage to ground? Or by checking temperature on lines? Or by sound? I'll have my tools back next weekend to make my attempt at this

 

By watching the digital temp on the dash.

 

Easy job , drain the coolant remove thermostat cover replace with AC Delco thermostat, and fill with 50/50 Dexcool and water.
Burp system.


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