Blowing hot air when moving but cold air when stop at light

T53864

MEMBER
MERCURY VILLAGER

98 Mercury Villager

It is winter here.
When the car is moving, the air blown is hot.
But, when the car stops at a light, the air blown is getting colder. If the car stops for a while, the air
will eventually be cold like outside.

Does anyone know what the problem would be?

Thanks,
Terry

6 Replies

SERVICE WRITER

MECHANIC
9,123 POSTS

Is your coolant level full?

Was this

answer

helpful?

Yes

No

+1

Wednesday, January 31st, 2007 AT 6:58 PM

TLA258

MEMBER
10 POSTS

Sound like to me that your not circulating coolant, with yoyr engine idleing at oper. Temp feel your inlet to heater core see if it is warm then feel the outlet.

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

+1

Friday, February 2nd, 2007 AT 7:07 PM

CLEAVAGE4U

MEMBER
69 POSTS

Learn me this there sweethardt,

How com the heat all comes back if the coolant ain't a circulate in when y'all are a moovin?

Was this

answer

helpful?

Yes

No

-1

Friday, February 2nd, 2007 AT 7:16 PM

TLA258

MEMBER
10 POSTS

When you are sitting still you car is at an idle along with water pump as you drive the rpms pick up and your water pump turns faster forceing more coolant around you may have worn impeller in pump or slight blockage in coolant system, worse comes to worse you may have blown head gasket, I just went through this with my car

Was this

answer

helpful?

Yes

No

+1

Friday, February 2nd, 2007 AT 7:23 PM

MERLIN2021

MECHANIC
17,250 POSTS

First off ya did't say what model car this is, but if it's front wheel drive like a sable they are famous for clogged heater cores. Try getting blown out at a radiator shop.