Bug Shield Noise

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by fish4funjb, Dec 30, 2008.

  1. Trucking

    Trucking Member

    I just installed a Weathertech hood deflector, and can not believe how much noise it creates at the top of the windshield. It sounds like hail is hitting the front of the roof pretty constantly anything much above 70 mph. It would seem it's redirecting the airflow so that the front w/shield side moldings are slapping around, but they're good and tight. Unfortunately I am going to need to remove and return it. Too bad, I wanted to keep stone chips off the front of the hood.

    Who has installed a hood deflector on a NBS Silverado/Sierra that is not creating noise? Which brand is it?

  2. Sierraowner5.3

    Sierraowner5.3 Epic Member 5+ Years 1000 Posts

    i get a tough of noise sometimes with mine, all i have is the GM bug shield straight from the dealer. nothing fancy. the little bit of noise is worth keeping the rock chips down.

  3. Trucking

    Trucking Member

    Thanks Alex. Maybe the GM shield is the way to go, I can live with a little noise, but not the racket the one I have is creating.

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    Well I bothered to read all the posts for this thread and I'll do the 3M tape application under the r/s and l/s windshield mouldings. Then keep an eye out for flapping hood hinge covers. Who'da thunk?
  4. f5fstop

    f5fstop Former Member

    On my 2013 I installed the AVS hoodflector. I have no noticeable noise or wind turbulence against the windshield up to 78 mph and with the wipers going for a short distance.
  5. Frankie Ray

    Frankie Ray New Member

    Yes ! I had to take it back, I wish I could fine one that didn't make so much noise, Any idea's
  6. Dana W

    Dana W Rockstar 3 Years 500 Posts

    Yes, given that debris and crap collects behind the things deteriorating paint, they re-direct rocks into the glass, cause wind noise, and rust at the mounting points, avoid them at all costs. My Burb which has never had one, is 15 years old, over 200 K clocked, and only has one or two paint chips in the hood.

    What I need here in Florida, is an Armadillo deflector for the undercarriage. I can't count the number of times I have had to pressure wash one of them suckers out of my suspension. When those guys get startled they jump straight up in the air, usually just in time to hit the front pumpkin.
  7. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    I have an ARE hood shield on my 05 yukon xl. I only get the "hail" noise if there is a really strong wind coming in a certain direction. It mounted in preexisting holes, There is enough room behind it that I can get my wash mitt and towel behind it when I was the truck. It has been on for over a year and I can say that I never have had any debris build up behind it. There is also enough room that when I wax my truck I can wax behind it. I can think of at least 4 times in the last year that I have seen a very large rock hit it and bounce over my truck, not into the windshield. I live in Michigan, with the freeze and thaw cycles here the roads always have large rocks and concrete loose on the surface. This is my 3rd NBS truck, the first with a hood shield. On the other 2 when a rock hit the hood it usually dented the hood and bounced off and smacked the windshield I have been told by a few people that caulking or using silicon to seal the the windshield moldings to the windshield stops the noise. My cousin did it on his 04 yukon xl and the noise stopped, he has a GM bug shield.
  8. Frankie Ray

    Frankie Ray New Member

    I had a AVS Ventshade on my 2013 GMC Sierra same problem took it back, I would think that someone would have one that didn't make so much noise.

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    HI : Did you get the chrome one, Have you notice any wind noise. I just took back a VentShade it drove me nuts. I like the looks of the AeroSkin, Little bit concern about the stick on design. How long have you had yours, By the way I have 2013 Sierra. Thanks
  9. 04-silverado

    04-silverado Rockstar 100 Posts


    I put one on my '04 Silverado... at speeds of 60+ the "NOISE" comes from the rubber flaps that "loosely" cover the hood hinge brackets... yes, sounds like random "hail noise". Other than that, there's no noticeable "wind noise" at the top of my wind shield.
  10. Dana W

    Dana W Rockstar 3 Years 500 Posts

    That is exactly the problem. All these deflector shields cause a lower than normal low pressure area at the front if the hood, At moderate speeds, about 40 to 50. Then, the rushing air all dives back down hard toward the base of the windshield, where the air slams into the stuff there. This may cause some tapping noise at the hinge covers and/or cowl grill. As you pick up speed from there, say up to 70 or better, the low pressure area will advance rearward. That is when the pressure starts actually sucking all that plastic cowling stuff up, and the hinge cover bits can start flapping bad. Wind noise at the windshield quiets down due to the air/wind pressure being a lot lower at higher speeds.

    Way back in the days before I realized these deflector things were more long term trouble than they are worth, I had one on a pick-up. While following a salting snow plow truck too close, out on the DC Beltway (495), I watched rock salt and sand come up and jump over the deflector about a foot, and then dive back down, raining down onto the hood and windshield. My clearance lights showed it just like some sort of wind tunnel test. I didn't do any experimenting, like trying to drive over 70 to make the junk fly over my windshield or anything like that. That was a long time before I moved to Florida.

    A very good friend of mine is a fluid dynamics engineer out at the Kennedy Space Center here in Florida, a for real Rocket Surgeon, who has run all kinds of research and tests on air, and water flow dynamics over and around all sorts of shapes and objects. He says the deflector shields are not just useless, but they are actually detrimental. They increase the impact energy expended onto your hood by objects that pass low over the deflector by actually pulling the stuff down behind it.They also reduce the efficiency of the HVAC system at higher speeds by reducing air pressure in front of the windshield making it harder for the HVAC system to pull in air.

    The next time I encounter an Armadillo, I will be certain to experiment, and see if I can get the little bugger over the cab by running the Burb up to 90 or so. I don't think I will ever get used to the sight of Dillo Jerky hanging all wrapped up over my control arms and shocks. Bleaeqeqhhhh!! Maybe I should put a deflector on the bottom of my bumper.

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