Cold Air from Heater

540

Asked by Nov 11, 2008 at 10:32 AM about the 1997 Mercury Grand Marquis 4 Dr LS Sedan

Question type: Maintenance & Repair

I replied to another post regarding this topic but wanted a new thread so maybe I could get a quick reply.

I have had my car in twice for this problem and it still isn't fixed.  I don't want to take it in again until I know more about the car itself so I can avoid getting another part replaced and still have the same aggravating problem.

I have a brand new control knob and rheostat (sp) and a new thermostat.  I think the problem is under the dash, it will blow hot then cold then hot again.  When it is hot it is REALLY hot, and when it is cold it is REALLY cold.  I end up driving with the air completely off except sometimes I need the defog on, so I have to use it stone cold.  

Can someone explain to me how heat gets from the engine to my ankles and toes, which is where I would like it to be?  Thank you.

3 Answers

115

hmm i used to have the same problem with my car, i would have to be driving for over 15min for it to stay hot. Heating your car is pretty simple basically when you run your engine the water pump in the car pushes antifreeze all throughout your engine to cool it down. So you have antifreeze constantly being flushed through your engine and you also have antifreeze in you radiator. The radiator is used to cool the fluid. The fluid goin through the engine is hot. So when the antifreeze is going on its route it passes through what is known as a heater core which is usually located at the rear of the engine under the passenger side dash. the fluid heats up the heater core which is made of metal. To get heat into your car there is a fan blower that blows air through that heater core and into the cabin of the car. the only other thing i could think of is maybe the heater core is partially clogged.

2 of 2 people found this helpful.
40

I would agree with billy. you could have a plugged heater core. you could also could have a problem with a mood door inside the dash. Inside most hvac units there are doors that control the were the air flows. the one that controls the temp. could be opening and closing when it is not suppose to and would cause you temp to change.

2 of 2 people found this helpful.
10,235

Keep in mind as well, that Ford makes use of a heater control valve under the hood that regulates the flow of coolant into the heater core from the radiator. Has the same basic concept as an EGR valve and if it went faulty, would give you the symptoms you are experiencing.

4 of 4 people found this helpful.

Your Answer

Add photo

Related Questions

  • Cold Air from Heater 3 answers

    I replied to another post regarding this topic but wanted a new thread so maybe I could get a quick reply. I have had my car in twice for this problem and it still isn't fixed. I don't want to take ...

    1997 Mercury Grand Marquis 4 Dr LS Sedan

    -

    Maintenance & Repair

  • Why does my heater fan only blow cold air? 13 answers

    When I turn the heat on in my car it only blows cold air. The AC works just fine and the fan does blow at full power but no matter how long the car has been running for the air still remains extremely...

    2001 Mercury Grand Marquis

    -

    Maintenance & Repair

  • Air from my heater doesn't blow warm air when sitting. 2 answers

    I have a 2003 Grand Marquis. Air from my heater doesn't blow warm air when sitting but when I'm driving the air is warm. What is the fix?

    2003 Mercury Grand Marquis LSE

    -

    Maintenance & Repair

  • Heater blows cold air. I have checked just about everything and am so frustrated. 2 answers

    My x husband disconnected the heater coil because it was leaking coolant into my car. He replaced the heater coil last year but I couldn't get hot air to come through. I have checked the fuses and bot...

    2000 Mercury Grand Marquis

    -

    Maintenance & Repair

  • Whyt would hot air blowi from a/c, heater and defrost setting 3 answers

    When turn on a/c or heat or defrost from Control Assembly nothing but hot air blows out of vents. Bland door motor and actuator have been checked and Okay. What else could be the problem.

    2009 Mercury Grand Marquis

    -

    Maintenance & Repair

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 1,835 nationwide Grand Marquis listings starting at $2,000.

ZIP:

Search Mercury Grand Marquis Questions

Mercury Grand Marquis Experts

#1 Tracy Hooks
Tracy Hooks
Reputation 5,540
#2 kbro
kbro
Reputation 2,080
#3 Js08016
Js08016
Reputation 1,790
View All

Related Models For Sale

Used Ford Crown Victoria
16 Great Deals out of 1,221 listings starting at $1,595
Used Lincoln Town Car
36 Great Deals out of 1,791 listings starting at $1,500
Used Chevrolet Impala
592 Great Deals out of 34,064 listings starting at $899
Used Ford F-150
2,059 Great Deals out of 207,350 listings starting at $1,499
Used Honda Accord
947 Great Deals out of 77,741 listings starting at $899
Used Ford Taurus
270 Great Deals out of 20,574 listings starting at $1,995
Used Cadillac DeVille
4 Great Deals out of 1,627 listings starting at $1,988
Used Buick LeSabre
19 Great Deals out of 1,919 listings starting at $1,000
Used Chevrolet Tahoe
557 Great Deals out of 31,373 listings starting at $1,500
Used Ford Mustang
537 Great Deals out of 45,845 listings starting at $1,999
Used Chevrolet Caprice
151 listings starting at $10,900

Used Cars For Sale

2011 Mercury Grand Marquis For Sale
33 listings starting at $4,495
2010 Mercury Grand Marquis For Sale
88 listings starting at $3,150
2009 Mercury Grand Marquis For Sale
6 Great Deals out of 83 listings starting at $3,599
2008 Mercury Grand Marquis For Sale
11 Great Deals out of 138 listings starting at $2,250
2007 Mercury Grand Marquis For Sale
8 Great Deals out of 132 listings starting at $2,495

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.