Blacky, you obviously do not know how these engines work with the computer monitoring and the temperature gauges. I suggest you offer advice for the stuff you really do know, rather than lead people looking for helpful advice down a garden path. The computer does NOT take the temperature gauge away when you need it the most.

 

I've thought since initially reading the first post, that the OP might have an "air bound" cooing system, maybe the next step should be taking it to a good radiator shop and having them pull a vacuum to evacuate any trapped air.

That might not be the only problem, something did cause the initial overheating, whether thermostat, blown head gasket, cracked head, or just being low on coolant remains to be determined.

I'm discounting the water pump, it's rare to have the impeller eaten away by corrosion, and a leaking pump should have given itself away with a persistent coolant odor and the inevitable puddle under the vehicle. But it should be checked just in case.

 

Remember my caveat: Assuming what Whopper says is true. He did say that if the computer senses a slow warm-up neither the digital readout nor analog gauge will work. Plus no AC.

Personally, if it was my car, I could care less. I would ensure that there was coolant right up to the thermostat, and install a known good thermostat with TWO 1/8" holes. That way, I would be guaranteed of hot coolant flowing past the thermostat, which would guarantee an open thermostat. The OP is a sharp guy, and will burp as needed. Hopefully the engine is slow to warm up, and maybe runs a little cold. For jollies one could have a ball at AutoZone testing for CO. BE CAREFUL - AND ESPECIALLY - WEAR EYE PROTECTION!! Fluids can be surprising.

Can't think of a better way to spend a lazy summer day.

 

Is it overheating, or simply dying. While driving or at a stoplight? I had problems with that the first day I had my 2008 HHR SS. They replaced the Control Module Sensor. Only took thema month to figure out what it was. Thankfully the car lot paid for the repair. I just bought mine and with the exception of that, this has to be my most fave car I've ever owned. I've yet to see another SS here in KY! Yay!

 

And btw.... the computers they hook up to it will show no signs of anything being wrong. I had to get the car to die in front of the mechanics. Up until that point, they just thought I was crazy haha

 

any updates
did you confirm the most obvious if the fan is working
although it will throw a code if the fan is not working on the ss

 

Well I took the thermostat off again and tried burping it again, still overheating. So I admitted defeat and took it to the shop and they said that it was the chain that moves the internal water pump had broke....so for a new chain, water pump and labor it's about $1100...nice huh.https://www.chevyhhr.net/forums/images/icons/icon9.gif

 

Wow, that's a rare failure, I wonder if the pump seized up and snapped the chain.

Sorry to hear it won't be a cheap fix, keep us posted.

 

Kylo:

Too bad about the possibly broken water pump chain.

How confident are you in that diagnosis? How did the mechanic arrive at that conclusion?

If the car was doing fine then suddenly overheated, you were right to suspect the thermostat.

The fact that there was no heat, however, would not be consistent with a failed shut thermostat. (In fact, turning the heat up full blast in both temp and fan can provide some emergency engine cooling.)

After the fact, we know that the original thermostat was ok.

So let's say at the beginning of the process the thermostat had been tested ok. Then one might have considered the water pump/chain. But you saw coolant flowing by with the pressure cap off - so that's neither consistent with the water pump/chain theory nor a failed shut thermostat. That would have led us to the possibility of air or exhaust gases in the coolant, which is more or less where I joined the discussion. I guess a thermostat not opening all the way - not completely failed - could have been a possibility.

If there was really no flow in that engine, you wouldn't get more than a few blocks before dangerous overheating - including probably a big loss of coolant into the overflow tank. You didn't say how you got the car to the shop, but if you've been driving around, I would be very suspicious of the water pump chain diagnosis.

If the water pump chain is broken, and you've done much driving around, there is a very real possibility of a warped head, damaged head gasket, and overheated transmission. In other words, make sure the car is worth fixing at $1,100. Maybe $1,100 isn't a fair price - I have no idea - but the same comment applies for half that amount.

I am puzzled.

 

Based on what you've said so far, here is what I would do.

First, wear safety glasses.

See if you can repeat your experiment watching coolant flow with pressure cap off. Obviously, you have to wait for the thermostat to open.

Use a flashlight.

If there is flow, then obviously the water pump is spinning.

If there is flow, look for bubbles. Bubbles may be exhaust gas leaking into coolant. AutoZone should have a block tester you can borrow that sniffs for CO - there may be a deposit of $40 or so.//

On another car (not an HHR), I had such an exhaust leak into coolant. There was no obvious evidence of coolant in the oil, or steam from coolant coming out of the tailpipe. Those classic symptoms of a blown head gasket were not evident.

With the thermostat replaced by a 1/2" flow restrictor (basically a piece of 1/2" heater hose jammed into the radiator hose at the thermostat housing) the engine never came up to operating temperature. With a thermostat, the engine would run too hot. With a thermostat the engine would start to overheat on the highway, but then, amazingly, immediately cool down slowing down through town! I could see bubbles in the overflow tank.

With a warm but not hot engine, I opened the radiator pet****, and took off the radiator cap. I drained enough coolant so that the level was just over the cooling coils for the automatic transmission. Started engine. Tremendous flow through radiator (transverse flow). Wonderful knowing that all that circulation was going on, and engine was running a little cool. Did block test for CO with AutoZone kit. Basically a rubber stopper sealing radiator while you squeeze and release a rubber bulb, which draws "air" from inside the radiator which first bubbles up through the test liquid. In this case, the fluid turned color indicating the presence of CO in coolant. The tester was either free, or a very small fee aside from the deposit. It took a long time and a lot of squeezes. (A helper revving engine may have helped get some exhaust into coolant.) After that, I put in fresh test fluid and tested the exhaust coming out of the tailpipe - even that took some squeezing, which gave me confidence I didn't have a false positive. (Remember to replace pressure cap BEFORE shutting off engine - else possible gusher.)

I used a liquid glass product to seal the leak. At that point I replaced the flow restrictor with a known good thermostat, with a 1/8" bleeder hole. Two years and probably 10 or 15 k miles later, no issues. Note that most of the thermostats that come with bleeder holes have a check valve jiggle pin - but you don't want any check valve action. And the hole should be big enough not to easily get plugged up - so one big hole is better than a number of smaller ones.