Sbraze

I have an intermittent problem on my 2006 HHR. Every now and then, maybe once a month the air compressor will not turn on. Along with this the temperature gauge also stops working. I am not sure if the thermostat is out or just the gauge. It always happens together, as soon as I hear the compressor kick on, the temp gauge starts working as normal, or as soon as I see the temp gauge start working I notice the compressor is working again. Always the same time. My guess is a short in the electrical somewhere, but everytime I make it to a mechanic to investigate it is working again and they cannot find anything.

Has anyone else had anything like this happen?

Thanks in advance for any help.

Snoopy

Have you checked your coolant level???

EDIT>>>>Both cold and hot. Cold will be at a very difficult to see mark on the bottle. I generally fill it to about 1 inch below the neck because of this. Never experienced any problem.

VinceP

What does the DIC say when this happens? Does it show --- ? If so I would suspect a sticking t-stat. If the coolant is not getting hot enough the ECM will not let the compressor come on. It cant tell if the car is overheating so it will not allow the additional load of the compressor.

donbrew

There are 10's of threads on the exact subject.

My guess is that you are overheating the car. Or you need a new t-stat.

Give the SEARCH box at the top of this page a try, You will find a huge amount of help.

Lucky

Welcome to the site I agree to all the above

whopper

If the coolant is up to the right level, it's the thermostat stuck open, typically with the gasket that is on the internal valve breaking down, and jamming the valve open. When that happens the engine is slow to warm up - and if it does not reach operating temperature within the time frame that the "computer" requires, the gauges show "----" on the digital display, and the analog gauge stays at the bottom.

When all that happens:
- the A/C is disabled until the condition is resolved
- sometimes the check engine Light will light up with a P0128 code is generated

It is also influenced by the outside ambient temperature - ie: when it is cold outside, the engine will be colder as well, and will take longer to warm up. After a short drive, the problem will often clear when the car is restarted because the engine is pretty much up to temperature already.

So it is not an electrical short or the A/C starting the problem and disabling the gauges - it's temperature related, due to the thermostat.

Lucky

Whopper. Very good explanation.

Sbraze

Thanks for all the help. I thought my fluid level was right, but I will double check it. It definitely happens when it is cold outside, but I do live in Central Florida, so cold is relative. :) The car is not overheating and the engine light never comes on. It is a short lived problem generally when it happens, it is usually cleared up before I even turn the car off, and my daily drive to work is just under half an hour.

Thanks again.

donbrew

Low coolant in the block can cause exactly what you describe.
Possibility of exhaust gasses in the coolant (head gasket).

When the engine is running and warmed up good try to watch for bubbles in the surge tank.

whopper

A few of us have mentioned that sometimes debris from a failed thermostat gasket can jam open the new thermostat, but we weren't positive or might have had doubts on it. Well last night (actually early this morning) I came across one :
https://www.chevyhhr.net/forums/problems-service-repairs-42/temp-gauge-c-stoped-working-37675/ MsBecky found exactly that on a failed second thermostat after a tip from firemangeorge - good on ya man!!!

So people, be aware that to be on the safe side, a complete flushing of the coolant system without the thermostat in place would be a good idea. If you decide to not do the flushing, and have a subsequent problem with the new thermostat, guess you better do that flushing after all. :)