Hi

Today was cold outside , I turn on the air Conditioning on HOT temperature (31.5C).
the car was in operation temperature and the heater not heat well at all.
driver'* side was a little bit warm air and the passenger side was cold .

what could be the problem ?
I already know there are several options : thermostat , dirty heater core , blend door ..

Make sure the radiator and overflow tank are filled to the proper level. If it hasn't been changed in a while, put in a new thermostat. Those are both inexpensive and easy fixes, and a high probability of fixing your issue.


Does your car have a temperature gage? What does it read?

I checked the overflow and it'* OK .
maybe the different between the driver and passenger temperature lead to the solution ?
why one side cold and other warm ? even that the warm side should be warmer ...

there is any option that the problem in the thermostat if the temperature gauge look fine and operation well ?

If you have checked the coolant levels, when the engine is cold(reservoir and radiator),and the levels are ok, then get engine to normal operating temp.....now command full hot.......with a thermometer in the register(check both sides), it should read 145-165F.......

If it doesn't then feel both heater core hoses....if both are hot, temp door problem......if the inlet is much hotter than the outlet(should approx be the same...hot), either air bound, or partially plugged(do a reverse flush)....

Is a code P0128 set?

I don't see a service light , and i didn't cheaked with OBD the car .
Today I gonna follow your steps and I write later what I found . Thanks

Last hour I cheaked the temperature in each vents :
Driver side - 92 F
Passenger - 80.4 F

Any ideas ?

Now I cheak the 2 hoses on the fire wall , Heater core hoses .
The are different between them of 68 F .

It'* normal ?

Did you check the coolant level in radiator and reservoir on a cold engine?

Did you check the temp from the vents, with the engine fully warmed, and on max heat?

Just feel the heater core hoses....they should BOTH feel as hot as the radiator hoses....if one is much cooler, it is air bound(due to a leak), or a partially plugged heater core....

What are you mean when you say "much cooler" ? I saw a different of 68 F ... both of them hot but the inlet more .
why in the passanger side i don't feel any heat ? only from the driver side .

Thanks