Typical Coolant Temps at stops/idle?
 

So I noticed my coolant temp the other morning when I was sitting in the driveway. I had driven to my dentist appointment, and had gotten back and was sitting there in the driveway, HHR in park, and I happened to have my Coolant Temp displayed...It read 214 deg F.

I was pretty surprised at first because since I got my HHR (August 2009) it stays right around 180-190 deg F. So I've been watching my temp the last several days and while I'm driving it pretty consistently stays in the 180-190 range, but if I stop at a light, drive-thru or am just sitting there the temp will creep up.

So I'm curious are these temps that I'm seeing typical for just sitting still? Not sure how much difference it makes, but I have the 2.4L just in case... :)

I have about 84k miles on it now, so I had been previously wondering if I needed to have the coolant drained and filled or anything - although when I asked this at the original dealership I was taking it to they just kind of brushed me off and said I didn't need to worry about that yet.

At idle the only air that will blow through the radiator is when the fan come on. I'm unsure at just what temp that happens..maybe 220. I see temps at 210+ in the Florida summers at idle, but when driving it reads 192. I also have a 2.4L auto with about 92K miles on the clock.

Being that this is a recent occurance I would not think outside temps will have this impact on the op even at idle.

My idle temps stay the same as running temps 185-194.

OP - I would check your coolant level and for any leaks. Temps getting hotter while at idle can be caused by too low of coolant which could let an air pocket effect the temp sensors readings or a faulty waterpump that is not circulating enough water to keep the engine cool. A leak in the system could also be letting air in the system when vacuum (inside the cooling system) is reduced while sitting at idle. When air mixes with coolant it heats it up. I am sure there are other possibilities too.

i see 194-205 while driving ... summer or winter

If your AC is on, the fan will run and your idle temps will remain constant. If your AC is off, at idle the fan is not running until the coolent temp reaches a threshold, in my 2007, 2.2 thats about 217 or so, then the fan starts and cools back down to something in the 180's.

Our HHRs' use DexCool* (orange) antifreeze, it is good for 5 years, or 100K miles.

So your '09 really does not need a drain & refill just yet.. The dealership wasn't BS'ing you.

This is in the owners manual also. fwiw.

Yeah I saw the Owner's Manual, it also has a note that mentions that it could need to be done sooner (50-75k if I remember correctly)...So that's why I was curious if maybe some would have had it done sooner than the 100k.

I saw 234 deg F sitting there the other night in the dealership parking lot when I dropped it off...I was sitting there in Park while I was filling out the night drop envelope, and thought that 234 seemed unusually high.

But then again, I know it runs around ~183 or so while I'm driving, but I can't remember in the past what the temps necessarily looked like when stopped/idle.

Sounds like maybe I need to check the level to see if that may be an issue.

234*, Yes I would check the anti-freeze level in the overflow reservoir.

& then make sure the fan is kicking on when it gets that hot idling..

50K to 75K might be referring to the auto trans fluid ?

Check out this thread on locating the coolant level markings, it can be difficult on the HHR due to the cramped under hood layout.

https://www.chevyhhr.net/forums/show...=coolant+level

Running 234° at idle in this mild weather really suggest that you're either low on coolant, or you have a possible problem with your thermostat or cooling fan.

What does the temp needle say when the DIC reads 220 and above? The two systems use different sensors IIRC and if they are not in agreement then you could have a sensor issue.

Based on my experience, and several others, the analog gage is not an accurate measurement of engine temperature. For example......

I have, on several occassions (Sunset Point), reached 235+ on the DIC indicator....... I drive with the DIC in "temp" mode MOSTLY all the time. The analog moved MAYBE less than a sixteenth of an inch. Now I suppose you can diagnose from this, but it would be tough. Several others have noticed the same thing.

That makes me wonder which system is actually closer to the temp??? I mean prior to dic displays all we had was the needle and it (without air pocket and/or bad sensor) was considered a reliable indicator of your coolant temps. Have you or anyone taken any temp reading with say a laser thermometer on the hoses or radiator? Or is it that the needles sensor is just slower to react to changes?

Temperature sensors in automotive applications are overwhelmingly of the "thermistor" type. That is - at different temperatures, the sensor exhibits a different electrical resistance, and the amount of current flowing in the electrical circuit changes. The amount of current flowing in the circuit is correlated to a displayed temperature.
High-quality thermistors are typically made from platinum or another precious metal alloyed with a suitable lower-cost metallic conductor. Their characteristic resistance gradients are known, stable, and are a foregone conclusion and have been for decades. If the electrical contacts to the thermistor are intact and the circuit is complete, the temperature reading cannot be wrong. The DIC coolant temperature reading is unerringly correct if the circuit is working.

The analog gauge in the HHR typically moves to the small hash mark just below the half-way mark on the gauge, and stays there. The HHR's acceptable operating temperature range barely moves the needle. It's function is to assure the operator that everything is in order - not to illustrate every minor variation in coolant temperature.

The OEM thermostats in Ecotec engines have a tendency to stick in the open position. This causes a wide variation in temperature readings when idling as compared to moving. When coolant temperature becomes a concern, go straight for the thermostat and eliminate it as the source of possible trouble.

jennybeeb,

I have over 160,000 miles on my panel with the 2.4L and have used it in all situations including over 30,000 miles of towing a trailer that weighs right at 1,000 lbs. The cruise temp is always at 180 to 192 and climbing a 5 mile 7% mountain grade with trailer at 55 mph only got it to 204 degrees . Idling will make it go up just a notch to 195 degrees. I have had it serviced by dale earnhardt chevrolet and use mobil 1 oil.

This is one of the main reasons i want the trifecta tune. have them set the fan turn on point at 180. I dont know about you guys but my 2.4 manuals performance takes a **** when temps start going up like 190 or so when at a light or going up an incline its really annoying. That along with PED makes this car suck sometimes.

coolant temp fluctuations
 

I have 103000 on my '08 SS and noticed that my temp gauge was going up to 220 degrees at times. I added coolant to the overflow tank and it settled down to a steady 190 to 195.

Settings the fan to a 180 turn on would mean the fan would run all the time.

Ya I know but when the temps are down I get better economy and power. You guys have any cooling mods that can help keep the temps down without having the fan on all the time?

x2.

Leave it be - the engine, like most now a days, is designed to run at the designated temperature. If you mess with it you will have drivability and emmisions problems.

X 2

Might be the Thermostat the rubber inside them fuggers up