Weird same here Snoopy, down with AC up with heater.

 

I have that happen too but my A/C fuse is pulled before winter starts. I've also seen it struggle getting to 170 when it is below zero - w/o the AC Fuse being plugged in.

 

Interesting does the a.c. fuse stop the a.c pump and fans from turning on when in defrost mode?

 

Is anyone here olde enough to remember when we put 160 degree thermostats in our engine for summer and changed it for a 195 when winter set in?

I worked at a gas station in the early 70's. I'd work evenings after school and a lot of weekends. I worked all through the week during the summer too.

All I was supposed to do was pump gas and work the counter as cashier, but I knew how to change and balance tires, fix flats, change oil, and even change thermostats, so I did.

It was normal for someone to come in wanting their thermostat changed for the season then have them decide they might as well get an oil change and a grease job and maybe a new set of snow tires,....

Made the boss happy, but was more work for me.

 

Awesome Grizzly! Not quite that old, but I always thought that fluctuation meant a bad thermostat.

 

Not always. I remember when my dad used to bring the alcohol antifreeze out of the '50 Ford Custom in at night so it wouldn't freeze. The antifreeze was put in gallon glass jugs and set by the oil heater in the living room.

In the morning he would go out and start the car then make sure all the drain plugs were in place and refill the engine and radiator.

He did this all winter. When spring came he swapped the thermostats and stopped draining the radiator at night.

A few weeks later when the weather was much nicer he decided we should go camping at the Kettle Moraine park. It really wasn't that far to the park from where we lived in Beloit Wisconsin but the car got hot enough to blow the antifreeze out shortly after we got there.

Dad thought maybe the summer thermostat had gone bad so he put the winter one back in. on a even shorter run to the grocery store the car over heated again. So, he took the thermostat out of the equation completely but putting both of them in the trunk.

Another quick run to town and back and everything seemed fine again. It wasn't until we went home from our camping trip that it even got hot enough to bring the needle in the heat gauge up off the pin.

Things were fine for most of the week then he had to run down to Rockford to get some parts and the car over heated again.

The real problem was the water pump had come apart inside. The impeller would turn sometimes and sometimes not.

Dad had bought the car used and god himself might not have known how many miles were on the engine and other parts.

It was a simple fix but I remembered it when many years later I had an '83 Camaro that was doing the same thing. I might be able to go hundreds of miles and not have a problem then I couldn't go up town for milk and it would over heat.

My first thought was thermostat problem but when I checked that and it was good I went directly to the water pump and sure enough the impeller was not exactly connected to the shaft that turned it.

I have no clue how they let go, it must be a manufacturing defect but it takes years for it to manifest as a problem

I have often wondered how many times the water pump turns when your going down the road at say 55 mph @ 2500 rpm.

The 2500 rpm shown on the tachometer is the crankshaft speed not the speed of any of the smaller pulleys.

 

Had vehicles form the late 50's, through the 60's and 70's, ether GM, Ford or Chrysler (a couple of VW's but they don't count), while I lived in Detroit and surrounding area. Don't ever remember the need to change thermostats for the seasons. Whatever was in it, stayed in it until an exact replacement was needed.

So nope, don't remember that. But I guess it probably would have helped with additional heat in the winter if a customer requested it.

 

Of course this would happen as I am in the middle of a move....
Well about a month ago my fan started to kick on after car was turned off. Called a dealer they stated it was normal the fan stayed on for a few minutes . OK
Then while driving car was fine and all of a sudden it shot strait up to the red. So I got it to the dealer and they said it was the thermostat. (Covered under power train) got a call next day and they said it needed a new radiator because it looked like someone poured something into the coolant. Then today got call stated no one poured anything in coolant tech found water pump failed and all the seals and gaskets broke down and flowed into the radiator and clogged it up. GM is Good Willing it and going to pay for all repairs,Towing and my rental. Hopefully I get her back tomorrow.

 

Grizzly
I remember the days well before. Fuel injection
Of putting the old 195 tstat in the winter and if we had a full size van a piece of cardboard in front of the radiator was mm mandatory when it was Below say 10 degrees

 

skalvinek, let me know how things are going with your HHR when you get it back and have been able to drive it for a bit.

Michelle, Chevrolet Customer Service