Hi Guys,


My car:
HHR, 2006, LS Trim, 136,000 miles, good shape given age.

Background:
I had a check engine, it was code p0128. After 100 miles, it goes away then comes... on and off for a month so I leave it. Now 1 month ago, AC dies. No more check engine, but I assume it is the Thermostat.

So I changed it today (thanks to this thread here) and...

Still no AC...

New Thermostat is opening and closing ok.... so not sure why the AC is still dead.

Heater works just fine.

Blower works (has a little sound; left over damage from the cowl/water deflector issue)

Radiator/engine fan works (it turns on when left in idle after a certain temperature)

I am getting coolant temperature reads on dash, I actually never had an issue with that.

I checked fuses and relays... all's good.

No codes.


Any ideas?




Please don't tell me to go to the stealership.

P.S. Thanks for all the wonderful information posted here, it has helped me a ton.

 

Have you considered it might be the compressor or out of freon or bad switch? You don't ever have to go to a dealership, unless you are seeking warranty repairs. However, AC repairs are better left to people who know what they are doing.

P0128 will come and go. It is actually the amount of air measured by the MAF V. the coolant temp.

 

Freon? Could be, but I was under the impression that my little 06 is a closed system, so unless there is a sudden big leak.

Probably one of the cheaper areas to start looking into.


Switch, you mean the blower resistor? or the actual dial which I turn on the dash? You think that could be it? Even if it works with heater? Could be a good place to start, again, it is a cheap thing to fix.

Compressor... I'm going to hope it isn't a compressor.


I guess I'll take it a a shop to get a reading from them, probably would be the best way to spend $20~ on this.

To be honest, it was my next step, just wanted to make sure I wasn't missing something obvious. I really went over all the old threads, and thought maybe... just maybe.

Oh, and I used ACDelco 131-158 for the thermostat.

 

Did you burp all the air out of the cooling system?

 

Closed system? I have never heard of an open system in automobiles. Some do leak.

I meant the button inside the heat dial.

Could be the pressure switch.

Does the AC clutch engage?

 

@Oldblue,
Thank you for the suggestion. I did, I think I got them mostly out, but will try again today.

@donbrew,
AC clutch! Thanks, I'll check it ASAP!

I'll report back here when I have some time during lunch to go check up on the car.

 

AC clutch now that I think of it has not been turning on. The reason I know: The fan must be on for the AC clutch to run if I'm not mistaken (feel free to correct me). The fan has hardly ever been turning on. The fan has only turned on when engine temperatures get high. I just tested now: AC clutch does not run.

I feel there might be a few more bubbles in there, but I need to wait for the car to cool down. Still odd if it were bubbles, since the thermostat is opening and closing on point and heating and coolant temp readings are working.

 

When you drive home park the HHR with the front end higher up a hill if possible, let it cool off a couple of hours and check the fluid under the cap in the upper rad hose, top up if required!

Check you fuse box under the hood, check the grounds for loose or corrosion

 

Thanks Old Blue, I will do just that. I'll report back here. I'm starting to think I might need to take it to an AC shop to get the freon/compression tested, since I believe the AC clutch won't kick on unless there is a minimum compression. I will see if instead of going to an AC shop I can buy a tool at a reasonable (sub $40) price to test.

I generally prefer to spend on tools which can be used for multiple fixes, than paying per fix.

Of course, all this after doing the top off and seeing if I can squeeze out bubbles.

 

I am doubting the coolant temp has anything to do with it now that the t-stat was replaced.

The cooling fan runs if the the compressor is running.

Here is the schematic; the dkgreen/white wire is the ground signal from the computer. I would look at the diode.