Heating problem hi i was vondering can a defective coolant temp.sensor cause no heating in the car.it blows only cold air the car doesnt over heat it and its running normally.

SOURCE: my heat not workini but blow cold air where is

Has the car been changed coolant since it was bought? If it is time to change, let do a flush through a heater core. There are 2 coolant hoses going thru a fire wall. One for coolant in and one for coolant out. Heater only works if coolant is flowing through the heater core. Therefore, there are one or both following cases contributes to the problem: 1-If the valve control coolant flow gets stuck, then it always closes  so there is no heat. 2-If the valve is working, but the heater core gets clogged up, then there is no heat.

SOURCE: coolant temperature sensor?????

um...strange ...engine temp reaches 210 before thermostat opens and lets water circulate ..fans go on before that normally..180 or so..hot air from heater going to cold air? strange...could you elaborate for me /us?

SOURCE: Seat Leon 1.6 - Heater blows cold air & occasional engine o/heat

first check the coolant level and for contamination always check cool or cold fill the resivoir and if it has a rad cap check it too if all looks good then maybe t- stat

dj_relly999

• 4070 Answers
• Posted on Feb 09, 2010

SOURCE: Fan is blowing cold air only

good day, you may have some heating core issues, anti freeze leakage, have it checked. hope this helps, have a nice day

SOURCE: volkswagen jetta over heating

hi tammy
it could be an air lock stopping the water from circulating properly i seem to recall this problem on the older VW Derby and audi 50 (same engine) there is a small bleed screw at the highest point on the cooling system that allows you to bleed this air out youll find its location in the manual

another thing to try is put a flushing agent through the system incase there are any blockages in the radiator itself

hope this helps