What is happening if there is smoke coming from the ac vents in the dashboard, but don't have a smell. It happens once the car has been running and after it rains, it sounds like water is sloshing around the ride side of the dash. hat is that?

Asked by Jul 21, 2016 at 02:55 AM about the 1999 Mercury Grand Marquis 4 Dr GS Sedan

Question type: Maintenance & Repair

3 Answers

35,965

Sounds like either a plugged condensation drain in the heater core plenum box or a leak from the window cowl. It isn't smoke but vapor/steam. Water, either from a leaky cowl or from running the AC, is building up in the plenum box and simply can't drain or drain fast enough to keep from sloshing around against the heater core (which is always hot) and turning into steam/vapor. Running the AC might cause this too. Find the end of the drain tube and fish a wire up it to clean it out.

292,855

Probably a leaky heater core. Is there a film on the inside of the windshield?

2 people found this helpful.

Thanks guys. It was a leaky heater core.

Your Answer:

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 1,222 nationwide Grand Marquis listings starting at $1,799.

ZIP:

Mercury Grand Marquis Experts

  • #1
    Tracy Hooks
    Reputation
    6,050
  • #2
    kbro
    Reputation
    2,230
  • #3
    Js08016
    Reputation
    2,060
View All

Related Models For Sale

Used Lincoln Town Car
29 Great Deals out of 1,455 listings starting at $1,900
Used Ford Crown Victoria
736 listings starting at $3,000
Used Chevrolet Impala
369 Great Deals out of 25,580 listings starting at $950
Used Ford F-150
2,280 Great Deals out of 208,584 listings starting at $1,300
Used Ford Mustang
273 Great Deals out of 37,438 listings starting at $1,350
Used Chevrolet Tahoe
526 Great Deals out of 37,726 listings starting at $1,250
Used Honda Accord
552 Great Deals out of 102,993 listings starting at $950
Used Toyota Camry
746 Great Deals out of 72,550 listings starting at $1,000
Used Ford Taurus
198 Great Deals out of 15,781 listings starting at $600
Used Cadillac DeVille
1,269 listings starting at $2,300

Used Cars For Sale

2011 Mercury Grand Marquis For Sale
18 listings starting at $4,995
2010 Mercury Grand Marquis For Sale
6 Great Deals out of 69 listings starting at $3,995
2009 Mercury Grand Marquis For Sale
60 listings starting at $2,977
2008 Mercury Grand Marquis For Sale
6 Great Deals out of 102 listings starting at $1,800
2007 Mercury Grand Marquis For Sale
8 Great Deals out of 97 listings starting at $2,995

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.