I’ve been reading about excess wind, road & tyre noise entering the cabin behind the seats via the hood drain exit valves. My 2006 2.0 is particularly noisy (only with the hood up) from 20 + mph. I’ve cleaned the drains with a trombone brush, flushed with soapy water and checked the rubber exit flaps for position and direction but the noise is still there, particularly on the passenger side. The drivers side flap is closed 100% closed but the passenger side remains 1mm open. I’ve poked and proddled to no avail and thought of a possible cheap and easy fix. I’ve ordered two of these 25mm I’D silicone end caps on Ebay…
Note - 25mm is the outside diameter of the white plastic drain outlets underneath the car so the caps should be a push on fit, if not some glue or a cable tie will be necessary.
The idea is to PARTIALLY cut through the closed end with a Stanley blade leaving approx. 8mm to form a hinge strong enough to hold the end in the closed position but weak enough to allow drain water to open. The caps, being silicone should last well and not perish like rubber.
Hopefully the experiment will be a success, I’ll post the results after they’ve arrived and fitted. Watch this space !!!
Oh, if anybody’s already done this, please let us know if it worked.
Sounds like an idea, but my Mk 2.5 tubes get blocked up with little bits of leaf, twig, cigar butts, general gunge. It’s this that causes the blockage rather than just rainwater, and gets cleared out with the trombone brush. So won’t your end caps keep this stuff in, unless you take them off regularly to clean right through, or will the hinge idea let everything out OK?
Depending on the thickness and strength of the “hinge,” they shouldn’t cause any more of a blockage than the stock rubber flaps which trap debris and jams them open or closed resulting in a floor flood, or the entry of road noise. Obviously they’ll still need tromboning through from time to time. The £85 MAZDA MX3 drain mod consists of TWO flap valves and a mesh & foam filter at the top which I’d say is more restrictive, although the filter will prevent debris from entering the tubes.
I reduced the wind noise on my 2.5 by inserting a plug of aquarium filter sponge in the top of the drain hole. I inserted a thin plastic tube in the middle of the plug ( a la toffee apple) for ease of insertion and removal.It also stopped any material getting into the tubes.
Sounds similar to the mod Mazda did with the Mk3 after numerous complaints about noise, blockages and flooding.
I’ve heard people describe the noise as sounding like blowing into a seashell. That’s exactly what mine’s like. This could be because the wind blows across the top of the open drain ends which sounds like blowing across the top of a milk bottle. If the ends were curved towards the rear of the car this might not happen. This be the case, a small shroud would alleviate the problem.
I have a 2005 2.0 MK3, and also feel that the noise eminating from the rear with the hood up is pretty noisy.
I found one of my drain holes was missing the flap (or so I thought), upon removing the whole unit, I found the flap was inverted. I assume a previous owner cleaned it in the wrong direction. Anyhow, I fixed this, but found that it made very little difference to the road noise.
Next, I removed the plastic cover behind the seats and installed a load of 10mm foam carpet underlay under the hood tray. This is double layered, the bottom layer spray glued to the floor and fuel tank with it folded back over it’s self and sparsly tacked to the underside of the hood tray. I also glued patches to the unseen side of the cubby holes.
Next I removed the plastic boot liner and put a layer behind this and on top of the shock turrets.
It’s made a subtle difference, but not to the point where I’m 100% happy.
Last year, my MOT guy let me spin through the gears while she was off the ground, we concluded that any noise was not diff or bearing related.
The next plan of attack, maybe at the end of this summer season is to replace the rear tyres.
Mine have a V tread pattern, which a mechanic mate of mine says are notorious for being noisy.
On a plus note, I have the luxury of mine being a summer toy, I don’t mind the noise with the roof down, this adds to the whole experience. So I only ever drive with the roof up if I inadvertantly get caught in a rain shower, this is where I want peace and tranquility.
Interesting !!! I ordered a dozen 10mm self adhesive closed cell foam sheets last week which should be here any day. What sort of a job is it to remove the plastic behind the seats and the boot ?
My tyres are Continental Contact 2s which I understand aren’t the quietest around. They’re approaching the limit on the rear with 3 mm left on the front which I aim to replace with Kumhos as recommended by many on the forum for quieter running, as well as their performance. The biggest issue is the wind whistling up the drain pipe which is worse on the passenger side where the drain flap isn’t fully closing by 1mm or so. I suspect there’s a bit of debris trapped that the trombone brush won’t dislodge.
As as experiment, I’ve made 2 push on plastic shrouds with angled ends which may (or may not) stop the blowing over a milk bottle sound. Will fit as soon as the wind and rain stops to see if there’s any difference.
Simple fix, get a pair of large heavy duty rubber gloves cut off the thumb and stretch it over the tube at the bottom then put a cut in the end to let the water out.
My mark 3 made a little wind noise through the drains so I thought until I bought a hardtop for it , when I put it on and completely cover the drain hole up it still made the same noise so it’s not always the drain holes
Funny you should say that. I blocked mine off top and bottom, went for a ride with the roof up and it was just the same. The drivers side’s quiet, the noise sounds to be coming from
the rear of the passenger window / behind the seat area. Checked the window seals and they’re okay.
Also to quieten things down remove the boot carpet and you will see the boot floor is like a drum. Good layer of Dynamat or similar will quieten things a bit
I’ve already ordered some 10 mm self adhesive closed cell foam for this purpose and will also line the wheel wells. Last week I filled the boot with bags of clothing and blankets thinking it would quieten things down a little, no different. Hopefully the new Kumho tyres plus sound deadening does the trick.
Had a new set of Kumho Ecstas fitted today. The good news is they’ve improved the ride quality by a noticeable amount, unfortunately the noise from behind the passenger seat is the same as before. Checked the drain flaps again which are both fully closed. The next job is to soundproof the boot floor, inner wheel arches and whatever else there is back there.
After almost 4 and a half years of hearing the same noise with the roof up and thinking “I’ll try bunging those drain holes up when I get home to see if it makes a difference” I finally got round to it.
I stuffed a wad of sponge into the bottom of each tube and the reduction in road noise was remarkable.
Now that I’ve proved (in my case anyway) where the noise is coming from I’ll scour the garage this weekend and cobble up a permanent fix.
The first thing I did was to stuff a cloth in the top of the drain holes behind the seats…no difference, blocked off the bottoms…again no difference. Then read about a member who laid a blanket along the plastic well behind the seats…tried, no difference. Then read about tyre noise and as I needed a set anyway, had them fitted this afternoon…no difference. The noise sounds to be coming from the rear top corner of the passenger window. The seal is good, soft and squashes up tight when the door is closed. I did however notice there’s a 4 inch length of the edge of the hood protrudes which might be causing turbulence and howling. I’ll try sticking some tape along the leading edge to change the aerodynamics. Fingers crossed.
If you havn’t fitted your foam already, then the hardest part is getting the little quarter section of centre console out. This is the 4" piece directly behind the cup holder thing, between the seats.
Mine snapped a couple of lugs, I’ve heard others say the same… good luck getting it off. It has gone back in again (minus the two clips) and is actually much easier to get out now
Literally, pull the front of the hoops off, remove the two screws, and remove the hoop rear covers.
Pull the wind deflector up and out.
Remove the inner sill plastics, again, these just pull out. These need to come out to remove the side covers (below)
Remove the seat belt top caps, remove the side covers (all held in with easy to get to clips). The side covers sort of fit in a hinge pattern, You remove the clips, and then rotate the side covers through 90 degrees toward the front of the car (if i recall)
The clips all have a smaller centre pins that you can pull out with your finger nails, once the pin is out, the clip comes out very easily.
The large plastic section is held in with the same easy to get to clips, once all the clips are out, it’s just a matter of manouvering it out.
The first time might take an hour, the next time 20-30 minutes.
Thanks Keat63. This will be a last resort and I’ve saved a few sheets of foam from insulating the boot area over the weekend. Unfortunately the noise is still there although doing the boot floor and the bulkhead behind the plastic trim has made a noticeable difference to general noise and makes the car feel more refined. The exhaust note is also quieter, I’m not bothered about that though. The irritating “wind” type noise I’d swear is coming from the left hand upper side of the passenger seat and I notice there’s a slotted grill between the drain hole and the seat. I’ve taped an old thick sock over these and will test tomorrow. Could have done so today but it would have been a criminal act to put the hood up on such a beautiful day.
I assume these slotted grilles are connected to the drainage system in some way, do you know what they’re for, or where they lead ?
