I just recently discovered a mildew smell and found water under the passenger seat. I have a sun roof,but pretty sure it's not coming from there or the door,cause it seems that the floor mat is slightly damp,and under the seat is really soaked. Could this be the heater coil ? How do i check it and is this a expensive part to replace? and what place sells the coil besides mazda? Do i have to take the dash apart? Thanks

 

Sounds like a plugged drain from the AC evaporator - when the AC is operating do you get condensation dripping out under the pass side just behind the front wheel? If not then the drain is plugged and is causing the condensation to build up until it leaks out the duct work and onto the floor.

 

Sounds like the heater core to me, that is exactly what my truck did, and the water doesn't even have to be there long for it to smell like mildew, get it fixed quick before it causes any serious damage to the engine cause the leak will only get worse if it is the heater core.

 

Thanks for the replys, I hardly ever use the ac since it causes my car to stall when i use it, i used it maybe three times a month just to unfogg the windows. The other thing that makes me believe it's the heater coil is that i hear bubble noises coming from the dash when accelerating. This is gonna be a nightmare! I'll check into the ac first but i have this feeling,it's gonna cost alot.

 

This happend to me and my hole pass side floor was SOAKED not sure if its the same thing but theres an AC line under where people put there feet so check and make sure its on ..

 

if it is the heater core you will smell the antifreeze. get a white cloth and dab it when it is wet and see if it is greenish. also run the A/C off one day and on the next. sit in idle for about five mintues. then check to see if there is a water puddle under your car or under your carpet.

 

The AC drain hose runs from the interior to the outside on the passenger side. I have known of some cases where a passenger can accidentally get their feet tangled in the hose and pull it off leaving condensed water to drain onto the passenger side carpet. Just reattach the hose and secure it with a zip tie.

 

Perhaps the awesome power and handling of the FD really scared your passenger.

 

Smells like antifreeze or taste like chicken ?

 

Has it been raining where you are?
Do you sometime park with the nose downhill when it rains?
10-1 it's the rear hatch leaking, specifically the nylon bushing that each plastic corner caps screw into.
More specifically, the triangular pieces directly in front of the tailights, in each corner of the rear hatch drain rail. Remove the 2 (3?) screws (black large head phillips type) and you'll notice a white nylon bushing that one of the screws attaches to. It is supposed to have some sort of gasket under it but it degrades over time. Remove it, apply some silcone or RTV around the bottom and re-install and voila', no more leak.

Regards,
Frank

 

I tend to agree with flyrx7, if it were the heater coil or A/C drain line all the moisture would be in the passenger footwell, not under the seat. I just went through the A/C drain line popping off a few months ago and the footwell was completely soaked, I am talking 1/4" of water all over before I noticed it. The water never made it over the bump to get under the seat.