I bought a 2009 HHR with a blown head gasket, most likely from overheating. I bought a 2.4L engine out of an 09 HHR with 33K miles on it and just did a complete engine swap. It has a new radiator and I can see coolant when I remove the cap from the Tee on the top radiator hose. When I first start the car the analog gauge starts at the bottom and moves to about the third tick (just under the halfway point). If I pull up the DIC, it fluctuates between 199° and 208°. The analog gauge does not appear to move. Is there a problem with the analog gauge? The temp outside is 77°, should the HHR run 208° while running down the highway doing 60 mph? I am in North Texas and fear what the HHR will run when the outside temp gets above 100°.

 

 

Was the old engine 2.4L?

The ECUs are programmed differently.

Did you replace the T-stat and T sensor?

What about the water pump?

Yes 199 is a high low end temp. Not exactly overheating. Should stay between 180 and 195, but up to 220 is not abnormal. The correct T-stat is 180 F by the way maybe you got a 190 in there.

 

I'd change the t-stat, it should run at 180 to 190 degrees. Be sure to get a GM stat as the after market ones can cause this problem and park the car front end higher than the rear to get the air out of the heater core

 

The original engine was a 2.4L abd this engine is a 2.4L out of a 2009 HHR, just like mine. What do you mean the ECU is programmed differently, do you mean from a 2.2 to a 2.4L? No I did not replace the thermostat in the 33K mile engine. Should I boil it to see if it opens? Original water pump in the 33k mile engine.

 

Yes between 2.2 and 2.4. I would take the T-stat out and look at it, they are marked what temp the open at, usually in C so you'll have to do math. There are still a lot of yahoos out there that think 190F is better than stock.

The function of the T-stat is to keep the engine temp UP, not cool it down. If you put a 190F T-stat in the lowest the temp will ever get is 190F, usually about 10 degrees more. That's why I suspect the wrong T-stat.

OK, 33K on the engine; how long has it been sitting around deteriorating? The water seals need the protection of Dex-Cool to keep them pliant (if that's the right word). How did the previous user abuse the engine? Did they read the Owners Manual and use the proper fluids and intervals? Did you? I don't know if the temp sensor part numbers are the same for the donor and recipient car, so I would get one for your CAR, because the ECU/ECM is programmed for the part number.

If you need an Owners Manual, check the link in my sig.

 

If it was mine, I would not worry about it. The analogue gauge hardly moves anyways - and the DIC temp display is probably fairly accurate, and will respond MUCH quicker.

 

This^^^^^^^^^

 

I went to RockAuto and ordered the AC DELCO thermostat. I also bought the lower radiator hose .. and a bunch of other stuff. I have the temp sensor off the original engine, might swap it as well. I'll update ya when I get everything installed. Ya I too think 207 is a bit hot for a cool day like today.

 

If you are expecting to replace parts, such that the temperature never fluctuates within the acceptable range, you are going to be very disappointed.