Hello,

I need some help diagnosing a strange thing my car did today.

It's a cold day (7 degrees) and I was running errands. After my last stop the engine temp was reading right in the middle of the guage, but the air was still blowing cold. (Last winter, by the time the air started blowing on high, it was always blowing hot.) This has been happening a lot over the last couple of weeks.

About thirty seconds after the air started blowing on high, something in the car suddenly smelled like it was burning, and then the air blowing from the vents immediately went from cold to hot. The burning smell then went away.

Does anyone have any suggestions for what this may be? My best guess is that my thermostat is sticking and needs to be replaced.

Thanks!

 

Have your car reach full operating temperature and open the hood and feel the upper and lower radiator hoses. They should both feel similar in temperature. If the upper is much hotter than the lower, then your thermostat is stuck closed.

 

Check the coolant level.

 

raise front of car, start, open cap and wait about 30 minutes while its raised up...this should get all the air out of the system which is most likely the case here..

IF that doesnt work - get a temp gun (IR thermometer) and check the temp before and after thermostat...it should open around 160-180...if before stays around that temp and after doesnt raise...problem solved replace thermostat

if it opens you can do the same with the heater core inlet and outlet...hot in, cold out means clogged....start with these

if you can do this all by yourself and never had your coolant replaced, it wouldnt be a bad idea to just drain, replace thermostat and fill....doesnt take long and its cheap

 

Definitely check the coolant level under the radiator cap!! I had lost over half of my coolant yet the temp guage never read too hot. Finally found problem (cracked overflow nipple - lost coolant, but level in overflow tank always looked OK) when started to lose heat at stoplights and I really had to look for problem.