2003 Mercury Sable HEAT IS OUT!

Tiny
SABLEOWNER2003
  • MEMBER
  • 2003 MERCURY SABLE
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 77,000 MILES
I own a 2003 Mercury Sable. My car WILL NOT put out heat. When I turn the dial (inside the car) to the first option on the left, the car will put out some warm-to-cool air. If I turn the dial to the right (any option), the car will put out cool air only.

I've tried flushing the radiator; replacing the thermastat; and making sure all the "tubes" (for lack of a better word) are clear and the heater core is working. The heat still won't work. Also, the car IS NOT building up pressure. I've tried replacing the cap on the antifreeze reservoire. Nothing is working.

My "handy man" mechanic thinks the heater control valve (that switches from cold to hot) needs to be replaced. He's trying to find out where this valve is located on the engine.

Can you help?

What do you think seems to be the problem?
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Monday, November 17th, 2008 AT 12:09 PM

3 Replies

Tiny
BMRFIXIT
  • EXPERT
Check heater core hoses
the two coming from the firewall
they should be hot
is one is hot and the other warm
then you have a clogged heater core and it needs to be flushed
if both very hot then I would suspect blend door motor inside on the HVAC box

Flushing heater core
Engine cool
lower the coolant level
Locate the two hoses running to the heater core
disconnect them at the engine side leaving hoses connected to heater core throw the firewall
use garden water hose and compressed air if possible
run the water and follow by air throw one side and out the other and vice versa
do that two to three times watching what leaving the heater core you are looking for the good flow and clear water to run throw
good luck
let me know
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Tuesday, November 18th, 2008 AT 6:30 AM
Tiny
SABLEOWNER2003
  • MEMBER
The heater core has been flushed with the water hoses. The water (antifreeze I guess) is moving smoothly through; both lines are HOT.

The thermostat was replaced and it opens like it's supposed to.

The radiator has been flushed.

We are now concerned with PRESSURE BUILD UP. No pressure is building up under the cap (that's on the antifreeze reserviore).

I tried replacing the cap. No deal.

Any idea why no PRESSURE is building up?

It's very cold here in Missouri.
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Tuesday, November 18th, 2008 AT 2:48 PM
Tiny
BMRFIXIT
  • EXPERT
If the two heater hoses hot then its the blend door motor stuck on cold
remove and replace blend door motor


http://www.2carpros.com/forum/automotive_pictures/99387_Graphic1_67.jpg

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Tuesday, November 18th, 2008 AT 7:24 PM

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