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.
10,475

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

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 1,745 nationwide Grand Marquis listings starting at $1,950.

ZIP:

Mercury Grand Marquis Experts

  • #1
    Tracy Hooks
    Reputation
    5,730
  • #2
    kbro
    Reputation
    2,130
  • #3
    Js08016
    Reputation
    1,870
View All

Related Models For Sale

Used Ford Crown Victoria
5 Great Deals out of 1,189 listings starting at $2,900
Used Lincoln Town Car
27 Great Deals out of 1,768 listings starting at $1,500
Used Chevrolet Impala
509 Great Deals out of 33,707 listings starting at $950
Used Ford F-150
2,283 Great Deals out of 181,563 listings starting at $1,000
Used Ford Mustang
690 Great Deals out of 38,315 listings starting at $895
Used Chevrolet Caprice
199 listings starting at $10,595
Used Honda Accord
1,063 Great Deals out of 60,938 listings starting at $999
Used Chevrolet Tahoe
663 Great Deals out of 39,382 listings starting at $1,000
Used Ford Taurus
254 Great Deals out of 16,489 listings starting at $1,850
Used Cadillac DeVille
4 Great Deals out of 1,640 listings starting at $1,995
Used Lincoln Continental
17 Great Deals out of 4,316 listings starting at $35,999

Used Cars For Sale

2011 Mercury Grand Marquis For Sale
25 listings starting at $5,450
2010 Mercury Grand Marquis For Sale
3 Great Deals out of 90 listings starting at $3,490
2009 Mercury Grand Marquis For Sale
5 Great Deals out of 83 listings starting at $2,899
2008 Mercury Grand Marquis For Sale
9 Great Deals out of 161 listings starting at $2,995
2007 Mercury Grand Marquis For Sale
5 Great Deals out of 113 listings starting at $1,995

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.