2000 Malibu

king1 wrote in
8dc112b6181445a7c81b2011ca58fa9d.RemoveThis@autoforumz.com:

> Daughter just bought a 2000 Malibuls, 50000 miles local driven
> from original dealership. Only know problem is a humming noise that
> comes from under dash or engine area, like a tuning fork sound. it
> happens at highway speeds and nothing you turn on or off changes it,
> do not know when it will start making sounds may be every day for a
> week and and may not make sound for a week. dealer can not find a
> reason.
>

this will sound very odd!! mentioning of the 'tuning fork' sound brought
back a nightmare i had when malibu first was revised....we had one that
would make a mid frequency harmonics kinda sound, AT TIMES. tried all the
normal channels first (checked drivetrain isolation, a/c line for contact)
but, like you, i couldnt get reproduction consistantly so it was difficult
to diagnose...i finally figured out it was the crosswinds along with
highway speed that produced consistancy (took a 99 out on interstate, drove
east, noise present. drove west, no noise. drove north and south, no noise.
drove east again, noise as before...i noticed flags were waving from north-
east direction wind, not hard wind.) i taped of the entire cowl area, hood
to w/shield gap, and noise gone. i slowly removed one section at a time
until noise returned. and it did return when i got to right/lower
windshield radius....examined our maint. records and found it had w/shield
replaced prior month...on very close exam ifound an area sort of void of an
even amount of urethane. took my fingers with a big gob of black RTV and
filled that area.,NOISE GONE...i found 2 other units w/same prob (also had
w/shields replaced). same fix repaired both. these are rent cars so i
definetly would have known if i was wrong. people luv bitchin about rent
cars.......never heard another complaint bout any of the three......sorry
so long. if it helps you great! if not you only wasted 5 mins.
reading......................................kjun