oms

I have a 2006 HHR. I bought it in November 2009 and it now has 9900km on it. I recently had my oil changed and now I have noticed the Coolant temp reading climbing when idling. Any time I have looked before it read 84C. Yesterday I got it to climb all the way up to 102C (by idling) then I turned on the heater full blast and it started dropping.The actual temp gauge went no higher than the first mark under the 1/2 mark. No Check Engine light on, no Temp Warning light on, no idiot lights showing at all and no steam from under the hood. We are just starting to get warmer weather here now and I don't want to be left on the side of the highway because the little buggy is overheating. Suggestions please. Thanks

1970judge

84 celsius is about 183 F, which is perfectly normal. Go outside and start you car today and drive it around for a while. It should get to around 88C or so depending on how cold it is up there this morning. Down here, my car cruises at about 195 F (90-ish C).

oms

Thank you for your response 1970judge. 84C - 88C I can live with. It's the climbing up into the high 90s when idling at a stop sign in the city or a drive thru. I communte for two hours every day, 1/2 is highway driving, 1/2 is city driving. On the highway, I can keep the temp down but not in the city. This morning it was 7C outside. On the highway the temp moved between 79C and 85C. Once I got into the city at each light it would creep up another one or two degrees. When I started moving it would drop down a degree. By the time I got to work and sat for maybe a minute or two idling it went up to 99C before I shut it off. My mechanic said it's not unusual for newer vehicles to run hotter and I shouldn't worry about it. Does anyone know what the range on the factory thermostat is? At what coolant temp should the fan come on so I can check it when it is running? Thank you.

skyeglen

Here ya go.

Parameters for cooling fan on/off

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The engine cooling fan system consists of one cooling fan and one relay. The relay is powered by the battery positive voltage circuit and controlled by a switched ground from the engine control module (ECM).

During operation, the ECM supplies the ground path for the cooling fan relay through the cooling fan relay control circuit. This energizes the cooling fan relay coil, closes the relay contacts, and supplies battery positive voltage from the cooling fan fuse through the cooling fan motor supply voltage circuit to the cooling fan. The cooling fan motor is grounded through its own ground circuit.

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)

1970judge

Yes, 99c is only around 210f or so. Perfectly normal.

oms

Wow. Thanks for all the information. I feel a lot better now that I have it. I've decided not to watch the Coolant Temperature display go up and down on DIC and just pay attention to the gauge. I figure as long as it stays close to where it is and there is no steam coming out from under the hood and no idiot lights are showing I'm good to go.

oms

An update. Yesterday, on my way to work I suddenly noticed the needle on the temperature gauge had not moved and sure as heck, I went to the DIC and the Coolant temp was flat-lined and the fan was going full speed. I turned around and made my way back home. If not for this forum I wouldn't have known what was wrong or what to do. I told my husband I needed a thermostat. Called the local dealership and they wanted $66.00 plus tax just for the thermostat. Called an aftermarket place and paid $56.00 for a thermostat and gallon of Dex-cool. After some colorful language and some bleeding (my husband's hands are too big to work in such a limited space) the thermostat was replaced and so far no more temperature problems. The old thermostat was pretty much hatched, hardly any seal left so I think it has been causing problems for awhile. Thanks again for the forum. If HHRs weren't such a 'cult' vehicle I doubt there would be this wealth of information on the interweeb. Too bad Chevy did such a shody job of making them cause I love my little buggy.