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Graphmaster Gerbil
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Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 9:11 am

Hey guys, I know this isn't the best place to ask around about cars but I know many folks here are tech guys in more ways than one. Anyway, this is about my 9-year old Mazda 3 sedan. About a year ago (~September 2013) the sunroof had a leak and at the same time, the interior door moldings (the soft part... I think it's made of some sort of synthetic leather/rubber) peeled off and the interior was covered in mold (yes, mold), particularly the door side moldings and the leather seats.Thinking that this was obviously a result of water stuck somewhere on the roof, I had the sunroof fixed and it's no longer leaking. Obviously, I cleaned the seats, the door side moldings, and wherever else mold grew on as well. After a few days I was shocked to see mold all over the place again. Thinking the car needed a good cleaning, I had it thoroughly cleaned inside out (ceiling, doors, seats... even had the carpet removed, washed, dried and reinstalled). So, for a while, I was happy again. I thought I solved the problem. After a few days I began to smell mold again (though there wasn't the heavy, visible mold infestation yet) but thought it was just 'stuck odor' and just hoped for the best. After a month, you guessed it... mold invasion again. Frustrated, I just clean the car when mold comes out.


Now, just the other day I noticed that there's a 'swishing' sound inside the car doors when the car brakes abruptly. I read a little about it and it seems the drain holes underneath the doors may have been clogged, so I groped underneath the doors and found what seemed like drain plugs. I tried to remove the plugs but it seems they wouldn't come off but I could press them down. And wouldn't you know it... water started to drip out of the drain plugs! There was SO MUCH WATER you'd think someone spilled a small can of water beside the car after I was done draining it! I did the same thing for the other doors and water came out from all of them! Now, I know this is a 9-year old car but we've had cars before that stayed with us for a fair bit longer and AFAIK they never had this sort of thing happen. Is this thing common with Mazda vehicles? The fact that water seems to be stuck inside all four doors seem to suggest they either need to be drained periodically (every what, 9 years?) because the window seals that are supposed to prevent water from getting inside the doors when it rains aren't perfect seals and water still tends to get in, OR the water deflectors inside the doors are starting to warp (all four doors at the same time?) and no longer work properly, which causes water to get in. Still, with drain plugs Mazda obviously knows water will inevitably get in. But why do the drain plugs need to be pressed down to let water out? Shouldn't water be able to drain out without doing anything so it doesn't accumulate? For FWIW the water doesn't get to the carpet.
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Re: Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 9:41 am

VW's have the same setup- pliable plugs that can get plugged up when debris builds up. Usually it's the sunroof plugs at the bottom of the doors that get stuffed up. You would benefit from joining a Mazda specific board for your model to get inside tips and fixes for the common faulty items every manufacturer has to contend with.
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Re: Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 9:44 am

Like you, I thought most car doors just had drain holes in the bottom of the doors. This thread confirms what you say "3 white tabs at the bottom of each door with small black plastic flaps that can be removed".

I wonder if Mazda tried to be clever and have the tabs hold the drains open when the door is closed and close them when the door is open so that the door doesn't drip on your foot? Or maybe they are meant to float up and open when there is water in the door but keep it sealed the rest of the time to cut down on road noise? After 9 years they are probably bent and battered and stuck and not opening properly, I'd just rip them out, but then it's not my car :)
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Re: Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 10:01 am

So yes, I have a 3 about the same age. They are the first 3's off the line for the US. And they all have this issue. While my sunroof hasn't leaked probably because I haven't used it much over the years I have had the same issue with water in the doors. I ripped out the stops. I can't answer any of your questions because frankly I feel that the first 3's were built craptasticly interior-wise. It certainly has turned me off of Mazda. However, engine and transmission -wise I have no complaints. BTW mine has 95,000 miles on it. I'll probably keep it another 6-12 month before I trade it in.

Some other issues I have had:
The black dash cracked into two right down the middle even after religiously using a sunshade.
The fabric on the doors began to peel off
The rear window plastic stops broke, I can still roll the widows up and down but going up they make a grinding noise at the top.
It eats tires, 3 sets sot far.
Constant headlight issues, Water leaking in breaking bulbs. About 7 replacements so far.
Paint hasn't held up well. Even after weekly hand washing and monthly waxing/claying the paint is fading, its especially bad on the plastic stuff, side mirrors, bumpers, etc.
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Re: Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 10:59 am

I have a similar issue with my '06 Miata. Mazda thought they'd be clever and put those little rubber flaps in the drains for the convertible top, but all they do is collect gunk and clog up the drain tubes. You have to clean them out with a trombone brush every six months or so, or you get water backing up into the cabin and trunk. :x I'd guess the flap are there to keep bugs out in dry climates (wasn't there an issue with spider-infested Toyotas?) but Mazda needs rework their flaps somehow so that they don't collect debris.
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Re: Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 11:21 am

Likely the insides of the doors are covered in mold and acting a spore garden for the rest of the vehicle, particularly any foam and padding assemblies installed inside the trim pieces for NVH control. Probably need to pull the door trim pieces, clean thoroughly, and completely spray out the insides of the doors with Lysol. Resist any urge to use bleach, though. It promotes rusting, and you've probably already got rust starts inside the doors from the standing water.
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Re: Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 11:23 am

It seems to be a common problem with Mazda in general. I had a first generation NA Miata for a while and the rear quarter panels were rusting on the bottom by the doors. The drain holes in those get clogged, too.
Graphmaster Gerbil
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Re: Mazda 3 Door Drain Plugs

Wed Aug 06, 2014 12:17 pm

Thanks for all the responses, guys. Really appreciate them all. Looks like I need to get those flaps cleaned up and have the interior door panels removed to see if I'm already surrounded by mushrooms, not to mention rust. I can't believe it took me this long to figure it out, but then again I seldom use this car. I have already guessed that there's standing water somewhere but I just couldn't put a finger on it.

Spider-infested Toyotas? I've read about spiders crawling inside the current model Mazda 6 and clogging up the fuel lines before and I bet it's not just Toyota and Mazda, and it's not just spiders that go hitch a ride. Creepy. I can just imagine people screaming and pulling over to shoo the bug out when one suddenly crawls out from somewhere while they're on the highway.

All told, I still wouldn't have any problems buying another Mazda after this. Certainly had a better ownership experience with Mazda than my previous Nissan Sentra, but then the Mazda is a newer design (the Nissan was a '00 model that originally came out in '94 I think) and I'm sure Nissan makes far better cars these days.
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Re: Mazda 3 Door Drain Plugs

Sat Aug 09, 2014 11:20 am

Working at Toyota I have never seen a spider clog up a fuel line EVER in 20 years. What they do Clog up with there webs is the EVAP system vents that are on the uderside of the car inside the carbon canister vent hoses causing chk engine lights in the Evap system.

As for the door drains I have come across many toyotas with clogged door drains also. Nothing a quick flap cleanup and a couple 1/4" holes drilled into the bottom of the doors and a coat of paint to stop any rust will not fix. Also removing the door panel to make sure there are no helicopters or pine needles inside the door causing the clogs in the first place.

Spider webs like to clog up the A/C evaporator drain hoses causing a leak on the passenger and sometimes the drivers floor also since the condensation from the A/C has nowhere to go. i have drained more then 1/2 gallon of water from some AC evap units in cars at least twice a year.
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