My 96 Mercury Grand Marquis is making a water rushing noise just behind the dashboard on the passenger side. I was told it could mean that the Heater box drain is plugged but I cannot find a drain. Can anyone advise?

Asked by Nov 10, 2013 at 03:05 PM about the 1996 Mercury Grand Marquis 4 Dr GS Sedan

Question type: Maintenance & Repair

Loud water rushing sound behind the passenger side dashboard when accelerating.  Not sure what is causing it but I do not have water in the vehichle.  I Was told it may be a clogged Heater box drain but cannot find the drain to clean out.

3 Answers


Passenger side, down low on the firewall, should be about 1 to 2 inches long, it could be painted so have a good light source when looking, sometimes getting under the vehicle makes it a little easier to find.

1 of 1 people found this helpful.

Thank you I believe I found it but I can't get to it without taking things apart so I will bring to mechanic. Thank you very much for your time and expertise.


Before taking to a mechanic, check the drain holes on the bottom of the inside of the passenger door. That door doesn't normally get used as much as the driver door and can get clogged with leaves,dirt, etc. They can get plugged up and the door will actually fill up with water and slosh around when accelerating. There should be 2 oblong holes on the bottom of the door. Open the door and look right where the weatherstripping runs along the bottom of the door. You should see the drain holes. Stick a flat tip slotted screwdriver up thru those two holes and see if a gush of water comes flowing out. That happen on my '91 Crown Vic last fall. I must have had 2 gallons of rainwater in my pasenger door. You'de be surprised how much water a door can hold if those drainholes are plugged up. Good luck, Kenny/MrBlueOval

1 of 1 people found this helpful.

Your Answer

Add photo

Related Questions

  • How do I disable the alarm on my 1998 Mercury Grand Marquis so I can start my car? 4 answers

    Hi, I have a 1998 Mercury Grand Marquis, it's been sitting for about a month now, and the battery died. I have a jumper pack and when I hook it up everything works fine (radio, lights, etc.) but as s...

    1998 Mercury Grand Marquis


    Maintenance & Repair

  • 2003 Grand Marquis replaced heater core, now air only blows out floor vents why? 4 answers

    our a/c stopped working, we were advised it was the heater core. The air was blowing fine out of all the vents. After replacing the core, we get the car back, the begins only flowing out the floor ven...

    2003 Mercury Grand Marquis


    Maintenance & Repair

  • a/c blower vents not switching 9 answers


    Mercury Grand Marquis


    Maintenance & Repair

  • Why wont the radiator fan run on my 2006 Mercury Grand Marquis 6 answers

    I have changed the thermostat and the cylinder temperature sensor and the car still runs hot and the radiator fan does not come on. What should I check next?

    2006 Mercury Grand Marquis LS Ultimate


    Maintenance & Repair

  • Leak - Mercury Mariner Hybrid 2009 , front passenger side. 4 answers

    Everybody, I was shocked that you all experienced what I am! Maybe we should lobby for a recall? I live in Northern California. In addition to being drier than a lot of places in North America, ...

    2009 Mercury Mariner Hybrid Base


    Maintenance & Repair

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 1,804 nationwide Grand Marquis listings starting at $2,250.


Search Mercury Grand Marquis Questions

Mercury Grand Marquis Experts

#1 Tracy Hooks
Tracy Hooks
Reputation 5,470
#2 kbro
Reputation 2,060
#3 Js08016
Reputation 1,770
View All

Related Models For Sale

Used Ford Crown Victoria
12 Great Deals out of 1,069 listings starting at $2,995
Used Lincoln Town Car
33 Great Deals out of 1,820 listings starting at $1,750
Used Chevrolet Impala
521 Great Deals out of 31,726 listings starting at $1,450
Used Ford Mustang
476 Great Deals out of 45,735 listings starting at $1,999
Used Ford Taurus
248 Great Deals out of 20,434 listings starting at $699
Used Ford F-150
2,194 Great Deals out of 206,316 listings starting at $1,499
Used Chevrolet Tahoe
550 Great Deals out of 29,234 listings starting at $1,699
Used Cadillac DeVille
7 Great Deals out of 1,640 listings starting at $1,999
Used Chevrolet Camaro
225 Great Deals out of 30,943 listings starting at $1,217

Used Cars For Sale

2011 Mercury Grand Marquis For Sale
35 listings starting at $4,995
2010 Mercury Grand Marquis For Sale
5 Great Deals out of 90 listings starting at $2,799
2009 Mercury Grand Marquis For Sale
8 Great Deals out of 94 listings starting at $3,790
2008 Mercury Grand Marquis For Sale
11 Great Deals out of 144 listings starting at $2,250
2007 Mercury Grand Marquis For Sale
3 Great Deals out of 140 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.