Loud banging noise from cockpit

AgentJ

Petty Officer 2nd Class
Joined
Feb 4, 2011
Messages
110
I have a 2010, Q7 SF, ever since I have had the boat, whenever I go over waves while on plane I hear a loud slapping sound coming from under my cockpit. It sounds like two pieces of fiber glass smacking against each other. Does anyone have an idea what I could be. At first I thought it might be my anchor in the front right storage, but I took it out and it is still doing it. Any ideas?

I asked the dealer about a broken stringer but they said if I had a broken stringer I would know it.
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,696
Re: Loud banging noise from cockpit

It probably *is* 2 fiberglass pieces smacking together . . .

. . . boats today are basically 2 pieces . . . the hull and the deck/cockpit. Usually the cockpit floor rests on or just above the hull & stringer assembly. With good wave action these 2 pieces will slap together.

If you could see if you can get visual access to the hull structure to check for anything extraordinary.
 

whmoore18

Seaman
Joined
Mar 6, 2012
Messages
64
Re: Loud banging noise from cockpit

How fast were you going and in what size waves/swell? If your moving at a decent clip 30+ over 2-3ft waves your going to have some banging noise. What your probably hearing is the echo from the waves slapping the fiberglass under the hull....My 215cc when I was in 3-4 swell and while I was going about 35mph it was noisy but when I backed it down to 24mph or so it was quiet. Slow down some these boats are made to fly over smooth water if your flying across waves you'll have noise. If you get on a $1 million sport fishing boat and fly through 4-7 seas you'll get noise too. Trust me loud bangs happen on those boats too..
 

bellhop

Seaman Apprentice
Joined
May 1, 2011
Messages
48
Re: Loud banging noise from cockpit

Same boat, same problem. You can stomp on the floor near the console and hear the same noise. Pretty much the deck isn't put together too well. They fixed it by forcing and siliconing pressure treated wood wedges under the deck on the side of the ski locker. Do I like that fix? No. The alternative would have been to pull the boat apart and no telling what kind of problems I would have after that.
 

AgentJ

Petty Officer 2nd Class
Joined
Feb 4, 2011
Messages
110
Re: Loud banging noise from cockpit

well i guess it does not hurt anything.... but it does annoy the crap out of me! Has anyone figured out a self fix? or is this gonna take me to the shop to get it fixed?
 

AgentJ

Petty Officer 2nd Class
Joined
Feb 4, 2011
Messages
110
Re: Loud banging noise from cockpit

it happens when on plane and going over wake from another boat or 1-2 foot chop.
 

NW AL Boater

Recruit
Joined
Aug 5, 2012
Messages
1
Re: Loud banging noise from cockpit

I have 2009 Q7 that has the exact same loud banging noise in floor under cockpit. Dealer says two pieces rubbing/binding together. They "ground" some clearance. Not sure what or where they ground.

I tested it, it seemed better, but eventually came back just like before

I've taken back again and they've ground more. Haven't tested yet. I did check another Q7 at our marina, and floor panel does have movement if press/stomp lightly.

It is very frustrating. I bought it used in fall of '10 and don't remember hearing it any last summer. Also it seems like then floor panel has more movement than orginally.

Any more ideas or solutions??
 

CaptainKickback

Lieutenant Junior Grade
Joined
Jul 23, 2011
Messages
1,060
Re: Loud banging noise from cockpit

I don't know the particular boat, nor the actual feasibility of this suggestion, but since several posters indicate you have access to the area, would some use of expandable foam make sense? Could separate the pieces hitting or at least deaden the sound.

Sea ya...
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,696
Re: Loud banging noise from cockpit

I did the expandable foam trick on my boat when I was doing the bulkhead repair. the cockpit sole rests on top of the stringer assembly . . . nothing really holding those 2 pieces together. So I injected some minimally expanding foam along the length of the cockpit sole on both sides. I did not keep the boat long enough to really compare the difference from before and after, but it is worth a try . . .

IMHO - grinding stuff down as the dealer is indicating is the wrong thing to do as it will tend to allow more movement and not less.
 

billbayjr

Recruit
Joined
Oct 7, 2013
Messages
1
Re: Loud banging noise from cockpit

it happens when on plane and going over wake from another boat or 1-2 foot chop.

I have the exact same boat with the same problem. Hit a big wave running pretty fast, now the banging noise occurs on most any wave. Did you ever learn the exact problem and how to fix it? Thanks
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Re: Loud banging noise from cockpit

Bill - This is an old thread and inactive. Please start a new thread and abide by the forum rules. Thanks.
 

AgentJ

Petty Officer 2nd Class
Joined
Feb 4, 2011
Messages
110
Re: Loud banging noise from cockpit

Well Bill...I took it to a Tahoe dealer and they told me it was two pieces for fiberglass rubbing together. They told me it would stop after a while. It is still going. I guess im going to have to take it to Bass Pro now that it is the off season.

Jason
 

bellhop

Seaman Apprentice
Joined
May 1, 2011
Messages
48
Re: Loud banging noise from cockpit

Bass Pro siliconed some wood wedges under the floor around the ski locker. Didn't think much of that repair but it almost cured the problem. Probably could have done that myself, I was thinking they would dazzle me with some high tech repair. At least the wedges were pressure treated wood.
 

AgentJ

Petty Officer 2nd Class
Joined
Feb 4, 2011
Messages
110
Re: Loud banging noise from cockpit

Did they do it from within the ski locker? Or did they actually get under the deck in between the inner and outer hull?
 

bellhop

Seaman Apprentice
Joined
May 1, 2011
Messages
48
Re: Loud banging noise from cockpit

From inside the ski locker. Just reached in there jammed them in and siliconed 'em.
 

A10ECGent

Recruit
Joined
Jan 18, 2008
Messages
3
I know this is an old thread but here is the answer. I have an 05 Q7 that had the banging problem. If you lean down in your ski locker and look towards the front of the boat right below the floor you will see a 2x4 that goes from stringer to stringer. That board will be loose I don't understand why Tahoe did not securely fasten it to the stringers but they didnt. My boat already had access holes cut behind the seat backs so what we did was reach through with a drill driver from the top and I laid in the ski well and used 3 " screws to fasten down the brace to the stringers then filled the gaps with silicone noise is 100% gone
 
Top