I have three Sonics all 2012-13... Strange rattle, can't tell where it comes from, audible mainly at less than 30 mph, seems worse on cold and windy days, no noise at highway speeds... Not a heat shield, not sway bar links, not license plates, not gas door, ...
SOUND LIKE YOURS?
FIX:
Inside the front bumper cover and behind the grilles are two plastic "air baffles" that direct incoming air to the radiator. These are secured ONLY with plastic rivets that fatigue and loosen up over time. The noise you are hearing is the mounting tabs from the upper baffle tapping against the HOLLOW steel bumper as you drive. The bumper is open on both ends, forming a perfect "resonating chamber." Also, the bumper can transmit the noise into the front sub-frame, making it very difficult to pinpoint the source.
Trust me, this is the problem...
PROCEDURE:
Raise car and remove front bumper cover, remove upper baffle. Cut two strips of 1-1/4 inch wool/fiber household door jamb insulation about 2 inches long. Carefully punch a small hole in the center of each wool/fiber strip and re-install the baffle with the insulation strips between the baffle and the bumper. Re-install bumper cover.
Its is best to do this when you have some other reason the remove the bumper cover. Today I needed to install a fog lamp insert, which is best done from behind, so I did the baffle while I had it all apart.
I've done this on all three cars and I've not had to re-do it yet. A bit "hillbilly," but it works.
Have fun...
SOUND LIKE YOURS?
FIX:
Inside the front bumper cover and behind the grilles are two plastic "air baffles" that direct incoming air to the radiator. These are secured ONLY with plastic rivets that fatigue and loosen up over time. The noise you are hearing is the mounting tabs from the upper baffle tapping against the HOLLOW steel bumper as you drive. The bumper is open on both ends, forming a perfect "resonating chamber." Also, the bumper can transmit the noise into the front sub-frame, making it very difficult to pinpoint the source.
Trust me, this is the problem...
PROCEDURE:
Raise car and remove front bumper cover, remove upper baffle. Cut two strips of 1-1/4 inch wool/fiber household door jamb insulation about 2 inches long. Carefully punch a small hole in the center of each wool/fiber strip and re-install the baffle with the insulation strips between the baffle and the bumper. Re-install bumper cover.
Its is best to do this when you have some other reason the remove the bumper cover. Today I needed to install a fog lamp insert, which is best done from behind, so I did the baffle while I had it all apart.
I've done this on all three cars and I've not had to re-do it yet. A bit "hillbilly," but it works.
Have fun...