Im getting this high pitch whistling noise when i turn on the heat. The pitch goes higher and higher..sounds like a kettle on the stove type whistling..i dont crank the heat or fan right away when i start it up in the morning, i do wait for it to warm up for a minute or two on driveway and then drive for about 5mins or so before turning it on...just wondering if this is a sign that maybe the thermostat is on its way out?

 

How could it have anything to do with the t-stat? More likely something under the cabin air filter or the fan getting ready to die.

 

well im thinking tstat because as the temperature of the car goes up so does the pitch - higher and higher until the engine is fully warm around 92, the high pitch goes away

 

does it whistle without the heater blower fan turned on? does the pitch of the whistle change with the setting on the fan switch?? When did you last if ever change the T-stat? all need to be reviewed and inquiring minds want to know!! I would pull the cabin filter and check for debrie

 

If not the fan, then Serpentine (or something connected to it) or water pump.

 

or it just don't know the words to that song!! and can't hum!!

 

To quote Lauren Bacall to Humphrey Bogart in To Have And To Have Not: "just put your lips together and blow".

 

^^ haha

umm im guessing the tstat is still original its an 08 with 96,000kms (~60,000miles)
i bought this car used about a year and a bit ago, so i think its original tstat and the cabin filter is fine. It doesnt sound like a belt, i know what a squeeky belt sounds like, this is a very faint high pitch where the pitch gets higher and higher as the engine temp goes up. Only when it reaches optimal operating temp it stops. AND it only happens when i have the heat on

 

Change the T-stat with a new style GM stat and replace the Dexcool , it is a start and almost due

 

ya thats what i was planning on doing this spring..i have yet to do a coolant flush yet on this i know its supposed to be done aroudn 5yrs..

so whats this "new style tstat" you speak of?