I have an 2006 HHR with 37000 miles on it- Lots of Highway miles. A couple of months ago overtemp light came on and the temp recorded to 258 degrees. The dealer said he replaced the thermostat and coolant - it ran well for a couple of months but I heard some gurgling under the dash at times. A couple of weeks ago it overheated again - took to dealer who now states it was air in the system and they had to backflush because there was also debris in as well. It has run fairly cool ( around 192-195) for a few days. Now it is starting again and seems to run around 210 -215 and will go up to 230 if idling. The dealer says it is ok to run that hot and I don't believe it. Says the fan comes on @ 223 so its ok to run that warm. Has anyone else had this happen - offer suggestions.

thanks in advance

 

Welcome, I have 06 highest i seen my temp was 210.

 

Here are the conditions that cause the cooling fan to turn on and off

The ECM commands the fan on under the following conditions:

• Engine coolant temperature exceeds approximately 106°C (223°F).

• A/C refrigerant pressure exceeds 1302 kPa (189 psi).

• A/C is requested and vehicle speed is below 100 km/h (62 mph) with A/C pressure above 1413 kPa (205 psi).

• AF23-5 Transmission fluid temperature exceeds 130°C (266°F).

• VT25-E Transmission fluid temperature exceeds 140°C (284°F).

• When the engine coolant temperature exceeds 125°C (257°F) at key off, the fan will run for up to 108 seconds.

The ECM commands the fan off under the following conditions:

• Engine coolant temperature drops below approximately 125°C (257°F).

• Throttle position is greater than 95 percent.

• Vehicle speed exceeds 113 km/h (70 mph)

 

That doesn't sound right. They can get warm, but shouldn't go that high. Maybe the problem is with the fan itself?

BTW, the fan speed is variable and controlled by the ECM. It kicks in at 5% at 196*F and varies via a set table, hitting 100% at 247*F.

 

The OP didn't say which engine he had, but attached is the actual fan settings from the '06 2.4 E67 ECM. They are the same for auto and manual.

GuitHHR, where did you get that data? Little corresponds to the HHR settings.

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to the site!!! Where in Michigan?

 

100 degrees in St. Louis today, just drove ours at 1pm in stop and go traffic and it never got above 195º.

 

That info is right from the GM online service manual. It makes perfect sense you you look way back to when front wheel drive cars with fuel injection and electric cooling fans started coming out the fans were set to turn on at about 220 degrees. Also as far as gauge readings many cars have a seperate sensor for the IPC gauge and one for the ECM. and the temps between the two can vary sometimes. I'm not saying cmelvin doesn't have a problem. I mean I havn't seen the temp read out on my HHR get above 210 myself and is been 105 degrees here on some days. All I'm saying is that his service manager wasn't lying when he said the fans should kick on at 223 degrees. I think that if his temp read out is reading that high something probably isn't right based on comparisons from other members.

 

Thanks for all the input - took it back in again and they found that the head gasket was blown and now they are replacing it.

 

Carleton - down near Monroe