Musty smell from air vents (not AC) 6R POLO

[Rose_13]

I've got a musty/damp smell coming from my air vents. It smells like that when;

• AC is off

• Air is NOT circulating internally

I've checked the filter at the passenger sides feet and it seems fine and I've had a good nose under the bonnet but can't find a source of the smell, not that I really know exactly where the air is coming in..

Which leads me here! Can anyone think why it'd be happening and/or point me to where exactly the air comes in to the car?

Thanks!

[RUM4MO]

One question:- do you use the AC often and leave it on until you are about to stop the car?

When you use your AC, it will strip out some of the water from the air and that gets dumped in the air plenum area, unless you disable the AC chiller some time before stopping that car, and then demand cold air so that warm incoming air heats up the the evaporator, your plenum will just get wetter and smellier until you use an AC bomb in that car to kill the bugs and the smell.

Edit:- the running of the AC in itself will not be producing any smells, it will just be the way that it is being used that is causing smells.

[exantas]

Ignore my comment

[Rose_13]

One question:- do you use the AC often and leave it on until you are about to stop the car?

When you use your AC, it will strip out some of the water from the air and that gets dumped in the air plenum area, unless you disable the AC chiller some time before stopping that car, and then demand cold air so that warm incoming air heats up the the evaporator, your plenum will just get wetter and smellier until you use an AC bomb in that car to kill the bugs and the smell.

Edit:- the running of the AC in itself will not be producing any smells, it will just be the way that it is being used that is causing smells.

I see!! That sounds totally right. So I need an "AC Bomb". I'll chase that up now, thanks very much for the help!

So AC bombs fill the car and this new sanitizing air is pumped around the vents system. If I'm having odour issues with the AC off, should I use the AC bomb with AC off? This is me working under the assumption that the AC and normal air are vented through different systems, the "nasties" being in the normal air system and so that's the one that needs bombing?

[joe6]

A quick temporary fix is to run the AC with the temperature set to max and car fully warmed up for about 10 mins. This will dry the system out and get rid of some of the smells.

[Ricmondo]

Sorry Joe, do you mean max which would be off or min which would be coldest.

Genuine enquirer, not taking the mickey!

[Rose_13]

One question:- do you use the AC often and leave it on until you are about to stop the car?

When you use your AC, it will strip out some of the water from the air and that gets dumped in the air plenum area, unless you disable the AC chiller some time before stopping that car, and then demand cold air so that warm incoming air heats up the the evaporator, your plenum will just get wetter and smellier until you use an AC bomb in that car to kill the bugs and the smell.

Edit:- the running of the AC in itself will not be producing any smells, it will just be the way that it is being used that is causing smells.

Sorry to bump with a repeat message but I'm about to use it and I'm sure by now my previous one is too far up to get much attention;

Should I use the AC bomb with AC off (running the normal air vents on full power?)? This is me working under the assumption that the AC and normal air are vented through different systems, the "nasties" being in the normal air system and so that's the one that needs bombing?

[Dink]

Think the last time i used an AC bomb. I had to put the ac on open all the vents and turn on recirc function to keep it circulating within the car.

Most AC bombs comes with instructions on there correct use.

[Rose_13]

Think the last time i used an AC bomb. I had to put the ac on open all the vents and turn on recirc function to keep it circulating within the car.

Most AC bombs comes with instructions on there correct use.

The thing is I don't have a bad smell when AC is on, only regular air and only when it's uncirculated which is why I was thinking perhaps I need to use it differently.

[Dink]

With the ac on you will be keeping the evaporator cold and the smell masked. The smell would go if didn't use the ac at all for a while (once the system dries out it will kill the smell off).

I think running the ac all the time seems to be the best option apart from fuel economy (I don't notice in my polo lol)

[RUM4MO]

I have used an AC BOMB on two cars now, each time I have set the air flow as directed but disabled the AC chiller function as it might strip the incoming recycled moisture from the BOMB out of the air - I've forgotten just how clear the direction have been - but I'm only using a bit of (my) logic and the instructions, seems to work for me, not sure if doing the opposite would make much difference - but I'm happy using my method.

[Rose_13]

I have used an AC BOMB on two cars now, each time I have set the air flow as directed but disabled the AC chiller function as it might strip the incoming recycled moisture from the BOMB out of the air - I've forgotten just how clear the direction have been - but I'm only using a bit of (my) logic and the instructions, seems to work for me, not sure if doing the opposite would make much difference - but I'm happy using my method.

This is exactly my thinking.

It's settled, bomb in > circulate air on high > AC off.

[Dink]

So the damp air containing the sanitiser condensing on the evaporator is a bad thing lol

[RUM4MO]

So the damp air containing the sanitiser condensing on the evaporator is a bad thing lol

Well if that happens, how is the rest of the air ducting going to get sanitised if only dry air is coming out?

[Dink]

Because the smell is coming from the evaporator. That's the bit that needs cleaning.

The evaporator has all the little fins in where the water settles and the mold starts to grow.