My 98' crown vic one day started to make a buzzing sound on the highway
when cruising at around 65MPH. The whole dashboard vibrated sort of like
the vehicle had a bee's nest hiding under the dash.
Problem was not present when driving at slower speeds unless it was a
windy day. Intensity and frequency of the noise varied depending on blower
motor speed with the problem being eliminated if the climate controls were
set to "off". Also, the noise was not present when the climate controls were
set on "max ac", even if the blower was at high speed.
Since both "max ac" and "off" close the door in the heater box that draws
in outside air, my suspiscion was that something was loose in path that
the outside air comes in through. Had recently replaced the blower motor,
so I knew the inside of the heater box was free of debris in the area that
draws outside cabin air.
Noticed a crack in the grate that covers outside air inlet to the heater
box and tried stuffing a thick layer of some folded up papers to insulate
the grate from the metal of the car. Problem now only occured when driving
the vehicle at higher speeds than before and when it did occur was not
as severe as before.
Below are some pictures of the part I replaced to fix the problem. Well
worth the $40 that it cost from ford.
(Click on any of the pictures above to view a larger version)
Later, I found that ford had issued a Technical Service Bulletin (TSB)
on this issue. The text of bulletin is avaliable by
Additionally, some crown victoria owners have expierenced vibration problems
with the cowl cover on the drivers side of the car. Unlike the cowl cover
on the passenger's side of the car, the noise is typically not affected by
adjusting the blower motor speed and will usually be confined to the drivers
side of the car at first. Some crown vic owners jokingly state that this
problem is a speeding ticket deterrent system, since it warns you when your
speed creeps over 75MPH. The problem is that the speed that the buzzing starts
at gets progressively slower as time goes on. For instance very few people
will complain about buzzing that only occurs at over 90MPH, but most all
will complain about buzzing that starts at 60MPH.
If you hear noises in your crownvic that are present only when the blower
motor is running, but are present even when the car is idling with the gear
selector in "park", suspect that something has slipped past the intake grate
and is wedged in the open area with the a/c condensor and the blower motor.
Around here, pine needles are good at slipping past the screen. But depending
on where you live in the country, you may well find other debris in there
too. Cleaning the area in question is not difficult, just remove the four
8mm bolts that hold the blower motor in place, then unplug the blower motor
and slide it out of it's case. When you've finished getting all the debris
out of the area, slide the blower motor back into place and reinstall the
fasteners. If you decide to test the blower motor while it's out of the vehicle,
use two hands to hold it's case while you have someone start the car and
adjust the blower speed. The motor moves large amounts of air and develops
enough torque that it can easily spin out of your hands.
Questions or Comments?
Email Me: [email protected]