This is an issue I encountered twice on two separate G body Buick Regals after upgrading the 3.5 speakers in the dash to some aftermarkets. Once the dash cap was reinstalled the plastic grille slots on the dash cap would rattle/vibrate from the speakers anytime the volume was turned up at least half way. Needless to say this can grate on your nerves, hearing a "buzz buzz buzz" come from your dash as you are trying to enjoy your music.
I've tried everything from running bass blockers to reducing overall bass. I even tried mounting the speakers under the dash (as opposed to the stock "over the dash" mount). Nothing really seemed to work. Apparently what I believe was happening was the rubber surrounds on the new speakers were hitting up against the underside of the dash cap. (the stock speakers had a felt cover over them and sat a little further down from the dash cap, albeit being top mounted) I eventually wound up just removing the dash cap just so I could listen to my music without all the vibrations and rattles. However that only made the dash look not only ugly, but incomplete.
Then one day I found in my garage a pair of used thick rubber O rings that were left over from when I had done a few fuel pump installs on my car. On all 1984-1987 turbo Buicks, the fuel pump is located on a fuel pump hanger and installed inside of the fuel tank. There is a thick rubber O ring that provides a seal between the fuel tank and the fuel pump hanger. This thick rubber O ring for the fuel tank pump hanger seal is a perfect fit for the 3.5 inch speakers located in the dash.
First I removed the dash cap and turned it over so the underside was exposed. Next using some all purpose super glue that is suitable for rubber, I applied a small line of glue around one side of the O ring. I then flipped over the O ring and pressed it to the underside of the dash cap around the grille area. I repeated the same thing with the other O ring. After letting the glue set up for about 20 minutes, I reinstalled the dash cap.
It seems most, if not all of the rattles/vibrations from the speakers are gone. I didn't even have to change any of the settings on the radio either. Now I can enjoy my music without all the vibrations plus the dash now looks complete.
Below are a few pics of the O rings in how I installed them.
I've tried everything from running bass blockers to reducing overall bass. I even tried mounting the speakers under the dash (as opposed to the stock "over the dash" mount). Nothing really seemed to work. Apparently what I believe was happening was the rubber surrounds on the new speakers were hitting up against the underside of the dash cap. (the stock speakers had a felt cover over them and sat a little further down from the dash cap, albeit being top mounted) I eventually wound up just removing the dash cap just so I could listen to my music without all the vibrations and rattles. However that only made the dash look not only ugly, but incomplete.
Then one day I found in my garage a pair of used thick rubber O rings that were left over from when I had done a few fuel pump installs on my car. On all 1984-1987 turbo Buicks, the fuel pump is located on a fuel pump hanger and installed inside of the fuel tank. There is a thick rubber O ring that provides a seal between the fuel tank and the fuel pump hanger. This thick rubber O ring for the fuel tank pump hanger seal is a perfect fit for the 3.5 inch speakers located in the dash.
First I removed the dash cap and turned it over so the underside was exposed. Next using some all purpose super glue that is suitable for rubber, I applied a small line of glue around one side of the O ring. I then flipped over the O ring and pressed it to the underside of the dash cap around the grille area. I repeated the same thing with the other O ring. After letting the glue set up for about 20 minutes, I reinstalled the dash cap.
It seems most, if not all of the rattles/vibrations from the speakers are gone. I didn't even have to change any of the settings on the radio either. Now I can enjoy my music without all the vibrations plus the dash now looks complete.
Below are a few pics of the O rings in how I installed them.