That smelly aircon again

[Steve McF]

When the weather finally gets better, I have a couple of treatments I want to use to clean up my aircon ducts and eradicate the smell that has been in the car since I got it.

I have used foam cleaner in the system before, and previously cleaned the mats with a carpet cleaner, but they didn't smell. I cleaned the seats with leather cleaner, and used leather polish on them. The carpets and seats don't seem to smell, yet this smell is still in the car and more noticeable when the blowers are on.

So I had a couple more queries - are there parts of the a/c system that need particular attention, and if so, are they accessible if I remove some trim?

Also, where is the a/c drain tube, and can that get blocked, meaning some stagnant water is lying in the car some where?

[sgould]

Have you washed out the chamber in front of the windscreen abnd changed the pollen filter?  If it's been blocked in the past, it can get slimy and smelly.

[Steve McF]

Is that the chamber behind the pollen filter where the fan is?

Last summer I used foam cleaner applied into the fan itself (via that opening where the pollen filter sits) and through all the ducting I could access. I changed the pollen filter at the same time, and it all seemed fine for the first 24 hours, but then went back to smelly again!!!!!

So next time I have a go, I want to make sure it's the last time I have to do it

[sgould]

Yes, the area under the black panel in front of the windscreen.  If the drain is clear, then a wash down might help.  But don't go mad and get the water through the pollen filter and into the car!

[Steve McF]

Just coming back to this as someone suggested to me that the smelly aircon could be due to a blocked aircon drain (under the car somewhere near where the steering column meets the rack). Has anyone ever cleaned this out?

How do you get to it, and how best to clean it out?

Might be worth my while doing this before I disinfect the a/c system again (if I can work out how to get under the car on my driveway), as I've done that before but the smell just comes back.

[Steve McF]

Well time for an update on this. I've done a couple of aircon disinfects since I've had this Aero which seem to be effective initially, and then the stale smell gradually comes back.

This time I tried a different a/c cleaner - Abro Air Cleaner - anyone else tried this? Rather than squirt all this foam in the a/c air inlet and fan from the bonnet side, you squirt this in to the centre air vent on the dash via the 2ft long tube for 10 seconds, and leave it for 10 minutes to break down and drip out through the a/c drain under the car. If it drips out black or green, then you need to do it again until it does drip out clear. Then you run the engine and the a/c for a few mins.

I managed to do 3 lots on the Saab, 2 on my Peugeot 107, and 1 on our Nissan Qashqai + 2....all with the same aerosol. Now looking forward to trying out the 3 cars over the next few days to see if it has worked

[Steve McF]

Now I have done multiple cleans of the a/c ducts using foam cleaners from the inlets side in the plenum (where the pollen filter is), and also through the vents in the dash.

This seems to resolve the issue for a little while but then the smell starts to creep back, and seems to be from the vents. Now the most recent foam cleaner I have been using breaks down within the ducts, and drains out through the a/c drains under the car. So I know the drains should not be blocked, but there is something in the system that is never getting fully cleaned out.

I wondered if it was actually in the ducts that demist the screen, as I have sometimes had condensation on the glass near the vents after the car has been parked up (droplets, not just mist) . This suggested there may be water standing somewhere in the system, hence my keenness to clean it out and ensure the drain tubes are clear.

Is there any other localised cleaning one can do that I haven't yet attempted?

The other theory was that someone before me had the car and was a smoker, and the residual nicoteen/smoke smell is in all the ducts/headliner/seats/carpets etc. Although I have washed the mats before and they did not actually smell like the smell I get in the car.

Any thoughts?

[Steve McF]

After multiple cleans of my aircon system with foam cleaners through the blower unit near the pollen filter, and through all the ducts via the vents in the dash, the smell from my a/c always seems to creep back.

So looking online, I see reference made to an evaporator core. Do I need to take something appart to thoroughly clean something at source?

Or should I just use an entire can of stuff in the vents all in one go (rather than the small amounts referred to on the can)?

[sgould]

What is the actual smell like?  We had a lingering sort of "curry" smell which turned out to be a weep in the heater matrix.

[Steve McF]

It's just a sort of sweaty sock combined with a kind of old nicotine smell.

A treatment will clear it up but after a few days it seems to creep back.

[Audax]

I'd be thinking about pulling the blower fan out and making sure it's properly clean and then try and clean from the pollen filter to the blower motor ducting as that shouldn't be too difficult, just time consuming and see if it helps.

[Steve McF]

I did wonder about that. Possible leaves debris in the fan etc.

How can i get the fan unit out to clean?

[smurkenstein]

You need to remove the glovebox and surround to access it from the passenger well.  You need the usual saab torx heads. Also there is a screw right at the back near the carpet - you might need an elbow to remove that one.

[Steve McF]

Well some time ago, I bought some AirVidox odour neutraliser - it consists of two powders you mix together, then add 60ml of water, shake the container for 30 seconds until it turns into a gel giving off what smells like chlorine!!!

You leave it in the car for 4 hours, and then run the aircon on recirc for another half hour.

We moved house in November and I now have a garage where I can actually get a car into, so I decided today was the day to finally try this stuff, as the Saab is in there, and at the end you have to leave windows/doors open to let the chlorine dissipate, which I did with garage doors at either end slightly open to get some airflow through. It was threatening rain outside, so the garage was ideal!!!

I might try and get the car out for a drive tomorrow and see what it is now like....watch this space.

Fingers crossed it has done a better job than all those a/c foam cleans I have done up to now

[Steve McF]

Well, I still haven't got round to cleaning out the plenum area, or removing and cleaning out the fan, but hope to have a look at that when the weather is better again. However, whilst look at general sundries for my car on EuroCarParts, I came across this cabin filter, which seems to be treated with some anti-fungal stuff. The filter is almost 3 times more expensive than a standard pollen filter, but I wondered if anyone else had used these? Might be worth a go after I do the aforementioned cleaning!!!