Undercoating for Road Noise Reduction

[JohnC]

I used the Mar-Hide rubberized spray on undercoating on the plastic wheel well liners in the front fenders, and it has reduced the tire/road noise quite a bit. The unsceintific way I measure the noise reduction was by turning the radio volume down as far as posible and still understand the talk radio guy, before and after the undercoating. I used 2 cans ($3.89 a can) on each side, letting it dry between cans. I also sprayed it into the inside of the strut tower. I think the hard plastic liners were acting like a kettle drum and amplifying the road noise. Pretty easy and cheap improvement.

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[DavidPIL]

Hi John,Nice idea. I've been thinking about doing that in the back but inside, under the plastic panels / under the spare tire holder. Waiting for warm weather because one plastic piece has to flex a little to get it out. Don't want it to break cuz of the cold weather. This that will work too? Seems to be a lot of noise back there as well. Sound use Dynomat but I'm cheap!Dave

[ragingfish]

Dave, keep me posted on that, sounds like a good idea...would be curious to consider that...John -- Can you get a bigger pic?

[ColonelPanic]

hmm, i've got the rubberized undercoating on mine with the exception of the front inner fenders... Aside from that, pretty much everything underneath is coated with the stuff, even around the rear fenders.If it makes a considerable difference up front, I'd kinda like to give that a shot... Never hurts to try to silence as much noise as you possibly can...I'd LOVE to do the Dynamat thing, but $$$$!!! And that I don't have!

[JohnC]

Quote, originally posted by ragingfish »John -- Can you get a bigger pic?Yep I changed the pic on the original post...still tuff to see since everything is black.I think the most improvement came from undercoating the inside of the upper shock tower. Although that plastic fender liner needed it too.Insulating the rear is a good idea, haven't gotten around to that either. We have had 3 280z cars over the past twenty years, and insulating the rear wheel wells helped alot in those. We just put whatever we had laying around in there, one of them had some 70's shag carpet stuffed in there. Dynomat is nice but big $$$$.The interior noise level in the Vibe isn't too bad, but I listen to books on DVD and talk radio while on my 2.5 hr. daily commute and it makes it easier to understand. (I am now paying for the loud music of my youthful years in hearing lose.)

[DavidPIL]

John,I honestly wasn't even thinking about just the wheel wells, that looks simple enough to do and looks nice too. Hope it helps me cuz the sound is almost like driving with the window open when sitting in the back. And rain hitting the sheet metal part where the back window sprayer is, man, it's annoying. Might try under there too.Dave

[DavidPIL]

YIKES!!!Went to Circuit City yesterday. Checked out the Car Audio stuff and noticed they are selling the spray-on sound damper stuff we've been talking about here. But they're selling it for just under $20 a can! This stuff can't be much different, if at all, from the undercoating spray you can get in most any auto store for $4-$5 bucks a can or less. That's seriously rediculous in mark-up from what the product is really worth. It can't be THAT much different, if it is at all! Get the spray on undercoating for much much lessDave

[remusrm]

what kind of percent of less sound you got? let me know, i might do it.

[DavidPIL]

raging,Took apart the back today. took out the plastic side panels and the whole spare tire cover. Used about 4.5 16 oz cans of rubberized undercoating in the back area. Kept the spray off the vents and really coated the sheet metal under the spare. I then masked off the 2 side panels, making sure to prevent the spray from getting on the snaps and any part that was used to fasten it to the body. Used about 2.5 cans on those, along with the underside of the spare tire cover. Not sure if it did any good. Noticed that only the sheet metal on the floor was resonant, everything else seemed solid. Stinks inside now - that was expected. I hope it airs out soon. My long trip to SC should help. Will be doing the wheel wells tomorrow. Will probably have a better sense of the achievement then. This stuff was only like $3 a can. There was more expensive cans and I might use those on the outside. The more expensive can says it resists scratches and nicks. Don't know if it's worth it but so far it's only $16 and gave me some personal time with my VIbe so it's all good.Dave

[DavidPIL]

Hey John,After a long road trip to SC, the way down being in nasty storms, I found that a lot of what I sprayed on peeled off. Have you had any problems with this? Seems mostly just on the plastic parts in the wells though. Maybe I didn't clean the wells good enough? Dave

[DavidPIL]

Hi ragingfish,Well, similar to JohnC's test on seeing how well it worked, I had a friend, while sit in the back while I was driving. She had mentioned the last time I was in SC about how much road noise she could hear back there. She noticed that it was much quieter in the back. It's hard for me to notice much up front but I do notice the stereo is, for lack of a better phrase, easier to hear. As mentioned in the previous post, the spray seemed to have peeled off of the plastic parts but there is much less plastic in the rear wells and as for the hatch area, it's all clean enough from the start to I don't expect there to be any issues like that inside.Dave