When it is cold outside and my heater is on, upon slowing down the car dies. The electrical continues but I must re-start the car. Has been going on for approx. 3 years. Dealership has looked at it a number of times and cannot get it to fail and the computer does not register anything weird or unusual.

 

What year HHR, and what engine, and what is the current mileage? When was the last time you had it in for a full service (oil/filter, air filter, spark plugs etc.)?

Is it only when the heater (fan I am guessing) is on?

 

But not the A/C?

My guess is that nobody has ever considered looking at the t-stat or the coolant. Just a guess.

 

When my '06 did that I cleaned the throttle body with the right cleaner. Hasn't done it since.

You might also look to see that the MAP senor is plugged in and that none of the wires are messed up. Mice like to chew on wires but your dealer should have seen that.

 

This is also a 2006. What cleaner did you use?

 

My car is also a 2006. What type of cleaner did you use to clean your throttle body? Is there any trick to this?

 

I just went to the Napa store in town and bought the lowest price can of throttle body cleaner I saw, Its a CRC product.

It was under $5.00 as I recall. Simple to use you loosen the connector between the air box and the throttle body and remove that hose then simply spray the stuff on the throttle body.

DO NOT TOUCH the insides of the throttle body with your fingers and don't use a rag on the insides either. You can mess things up by doing that.

When I did mine it was a fairly warm day and it didn't take long for the stuff to evaporate. Once I figured I had done a good enough job of cleaning it I put things back together but hadn't noticed that the wires to the MAF sensor were not plugged in.

The car started fine and even went down the road but it shifted very abruptly and just wasn't real happy about running so I went straight back home to check my work. The MAF sensor plug is on the underside of the air box so it took some serious looking to find it. Once I had that plugged back in the car ran like it did when we got it.