Dandy_don

92 coupe with 140k. For as long as I have owned the car it has made droning, almost hollow drum like noises when the car is driven on concrete pavement. Which is often considering that I live in Houston and most roads are concrete. Elevated bridge concrete pavement sections are particularly bad.

The noise is greatly reduced (almost eliminated) the few times I get to drive on asphalt roads. This tends to rule out wheel bearings but I have not changed them so I suppose it is possible but not likely.

Mitigation efforts thus far.

Sound mat installed on rear half of the bodywork including the wells to the rear of each wheel

thick acoustic mat laid on the flat floor (over the spare tire and well but under rear carpet.

Applied 3 cans of 3M (the ggod stuff) spray on undercoating in each rear wheel well

While the above has probably helped the droning/hollow sound is still there and is annoying/tiring on 3-4 hour drives that I make weekly these days.

Any ideas or thoughts on this condition. It is really my only gripe about this car- other than that it is the perfect car for my use.


Don

tamathumper

Don't know how long you've owned the car... how old are your tires? They get hard (and noisy.)

Dandy_don

both front and rear tires are pretty new. When I bought it the tires were very old, replaced them and it got quieter but it is still loud.


D

tamathumper

Hmm. Did you put the same brand of tires back on it? Do they have a square, blocky tread? The fact that it drones on concrete and not on asphalt really only leaves the tires as a candidate for the noise, as far as I know.

BikePilot

Mine is also rather noisy on concrete but quiet on asphalt. Fairly new tires and not a blocky pattern. I think that's just how these cars are. Fortunately roads in FL seem to be mostly asphalt.

ryan@usaimage.com

I think it is the nature of the hatch shape to shoot the sound forward and make for a loud car. You could try to cut some sections of that egg-crate sound foam and place it on the floor to see if it cuts some of the drone down.

The cabs are not as loud for sure.

JimV8

Turn up the radio. That always works for me when I hear rattles and vibrations.

968 GUY

I bought Sumitomos, they are the noisiest tires I have ever had. HTRZ II's

bombfactory

The rear hatch definitely bounces road noise forward, especially if you have bigger and wider rear tires. Try some dynamat in the rear quarters and all over the rear hatch area. I'm not finished with my dynamat application yet, but covering the inside of the outer skin on both doors knocked road noise down considerably, and I plan on covering everything behind the rear seats.

Dandy_don

Thanks all for the replies. Probably the best advice is to turn up the radio. I have always suspected that the hatch glass shape bounced the sound up toward the passenger compartment. The dyna mat I installed helped some but not as much as I had hoped. I have a few other ideas I will try and let others know of my results (or lack therof)


Don