dbarberaz

Well I can tell you after work last night about 5:45 I got in and it said outside temp was about 122. Yes it was sitting outside all day. As I drove on the freeway the outside temp dropped to about 112. The coolant temp was reading about 212 about half the way home about a 40 mile drive. It soon cooled down to about 200. The gauge itself did not go over half way. Everything seemed to cool down and work just fine, other than the outside temp was over 100 last NIGHT yes at NIGHT

john 11

Thank You to everyone who has replied. I will keep an eye on it for the next couple of days to see if part of the rise in coolant temperature was due to the extra load and mountains in West Virginia. We don't have a lot of hills in Charlotte but it is supposed to be hot here the next few days. Thanks Again

TxSkyPilot

Keep a close eye on it. I had a faulty thermostat at 300 miles that caused engine damage and resulted in a new engine. There have been others with thermostat problems.

JT's HHR

I was having the same problem. Took the HHR to the dealer and they replaced the thermostat. No problems since.
If you can't get to the dealer right away and need cold air, disconnect the battery for a few minutes, that will reset everything for awhile, the temp guage will work again along with the AC

cj krause

i added Water Wetter to the system before i went on vacation in the mountains. fully loaded and ran it hard and never got over 202.

i tried to find Purple Ice and never could find it for sale anywhere.

http://www.royalpurple.com/prodsa/prpice.html


Purple Ice is a high performance, synthetic, radiator coolant additive for both gasoline and diesel engines. It is formulated to reduce the surface tension of the coolant, which improves heat transfer through the cooling system while providing additional protection against rust, corrosion and erosion.

Reduces Coolant Temperatures

Extensive testing confirms Purple Ice reduces coolant temperatures better than comparable products while providing extra corrosion protection. For example, the average operating temperature of a 350 c.i.d. V8 engine (equipped with 160° thermostat) when dyno-tested with different coolants are:



A.
Standard mix of water and glycol (antifreeze)
228° F

B.
50 / 50 water / glycol mix with Purple Ice™ added
222° F

C.
Straight water (no corrosion protection)
220° F

D.
Water with Purple Ice™ added
200° F

Recommended Treat Rate
For use with antifreeze -- 1 oz. / quart of cooling system capacity
For straight water applications -- 1.5 oz. / quart of cooling system capacity
Note: Minimum of 20 percent antifreeze recommended in street driven vehicles.

c-h2oman

I had the same problem on my 2LT with the 2.4. They downloaded the latest program and the problem was resolved. Be sure to also check all the fuses under the hood and under the access cover on the right side of the console for looseness.

DohnerJ

I am new to the forums on here i actually found the site via google when i typed in temp gauge not working. I am having this problem with my 07 hhr 2.4 so should i just change the thermostate and go from there. I am pretty mechanicly inclinde so its nothing to change it for me just need to kind know if this is a good starting point. I also got the P0128 code going on with the gauge not working. THanks for all your help

whopper

Welcome. You are headed in the right direction with the thermostat replacement - see https://www.chevyhhr.net/forums/how-tutorial-library-21/how-save-%24350-00-thermostat-replacement-2-4l-p0128-24493/ for details on changing it yourself - it's not a big job and you can save some $'s, and get your hands dirty at the same time

DohnerJ

Hey I got a new thermostate and coolant today I spent 36 on parts took me 10 mins to change it and about another 10 15 to burb the system. Worked like a charm. The old thermostate the middle gasket was halfway pulled through and sticking the tstat open. But thanks to all you guys on here for pin pointing this issue and saving me a trip to the dealer.

MadeInDetroit

I replaced my temp sensor trying to solve the problem as well. Oddly enough, the Check Engine Light came back on AFTER I PASSED the GA emissions test. I checked the code with my own auto scanner and sure enough it was the P128 returning. So I got to thinking. What if I erase that code again. BAM! Problem solved until I turned on my A/C defroster, then its back on again. Erased the code. Back off again. Seems like EMC code malfunctioning too me.