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Aircon musty smell

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HI all

I don't use aircon a great deal but it works fine and recently regassed. no smell, however, if I turn off the aircon it smells musty after switchover.

I don't get a smell if I just don't use the aircon at all - only if I put it on then switch off later.

is there a bit I can clean out somewhere - and how where to get at it?

I've put those anti bac airfreshener cans through the system several times with no luck, there must be something needing a clean....

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Have you checked the cabin filters in the engine bay; sounds like they could do with a change?!

 

I have used this in the past to good effect: http://www.cleanyourcar.co.uk/interior/autoglym-aircon-sanitizer/prod_803.html

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Had this with both my E39s. The sanitiser 'bombs' do work as a temporary measure but BMW have a procedure to thoroughly clean the evaporator (buried deep in the bottom of the dash) by drilling a hole and then spraying the correct cleaning fluid on to the evaporator to get rid of the smell-causing mould which grows there when the A/C hasn't been used for some time.

 

It's not a difficult DIY but having carefully planned it out you need to carefully calculate the position of the hole. Whatever you do, do not drill too enthusatically and accidentally 'follow through' with the drill bit into hole since you don't want to puncture the evaporator. Bugger this up and you'll be taking most of the dash out to replace the expensive evaporator! (BMW have a special tool for this job which has a drill depth stop built into it.)

 

The evaporator is contained in a plastic housing with an outlet at the bottom to allow condensate (water) to drain to the outside when the A/C is working hard. Small dribbles or tiny puddles of water below the car are often signs that condensate is draining away correctly. You need to be careful to not drill your hole too close to the bottom of this plastic housing since you don't want condensate draining into the car.

 

The hole is used to poke one of those flexible plastic pipe extensions that come complete with A/C cleaning aerosol like this one:

 

http://www.amazon.co.uk/Liqui-Moly-4087-Climate-Control/dp/B001CZKC4G/ref=sr_1_2/276-7093050-5905943?s=automotive&ie=UTF8&qid=1438363566&sr=1-2&keywords=liqui+moly+cleaner

 

Location of the evaporator:

post-52803-0-69719800-1438364670_thumb.j

(Above) In the front passenger footwell behind that carpetted trim panel. Remove the phillips head screw & washer then slid the trim panel toward the seat.

post-52803-0-82725300-1438364797_thumb.j

(Above) I drilled a hole just about opposite that bracket.

post-52803-0-88485300-1438364919_thumb.j

(Above) Bought a handful of these rubber plugs from eBay for a couple of quid but you only need one. Notice how the tapered design of the plug allows for a snug fit. I think I drilled a 16mm hole. Really important when drilling not to let a disk of plastic drop into the bottom of the evaporator housing since there is some potential for it to block the drain hole.

post-52803-0-52268900-1438365175_thumb.j

(Above) I use this stuff and spray it in and around the evaporator with a lance attached to one of those garden pump sprayers.

 

Once you've finished cleaning the evaporator fit a rubber plug/bung to seal the hole up. The plug makes repeat cleaning of the system a lot quicker.

 

Well worth spraying the anti-bacterial cleaner into the cabin air intake system (with the fans running) by removing the plastic 'trumpets' that direct air from the cabin filters through the bulkhead into the cabin. Spray with a fine but generous amount of mist. Change the cabin filters & clean the cabin filter housing with the stuff as well. Spraying into all the cabin air outlets is also well advised.

 

I do this cleaning job once a year on my E39s.

Edited by DepthHoar

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^^^

This!

Air con is designed to be left on, it keeps the system fresh and the seals fully lubricated so the system doesn't slowly leak out to the atmosphere!

Sanitise your system and keep it running!

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......keep the A/C on all the time in the 530d as well......but it still gets a bit too whiffy. 

 

(Maybe it's because I live in a humid part of the country - Scottish Highlands - plus the system has to shift a lot of moisture from the car's cabin during the cold and generally moist winters??)

 

The M5 goes into hibernation in a heated and humidity controlled garage during the winter so the bacteria have plenty of time to multiply. Easy to understand why it gets a bit smelly in the early summer when it hits the roads again.

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On 7/31/2015 at 7:12 PM, DepthHoar said:

Had this with both my E39s. The sanitiser 'bombs' do work as a temporary measure but BMW have a procedure to thoroughly clean the evaporator (buried deep in the bottom of the dash) by drilling a hole and then spraying the correct cleaning fluid on to the evaporator to get rid of the smell-causing mould which grows there when the A/C hasn't been used for some time.

 

It's not a difficult DIY but having carefully planned it out you need to carefully calculate the position of the hole. Whatever you do, do not drill too enthusatically and accidentally 'follow through' with the drill bit into hole since you don't want to puncture the evaporator. Bugger this up and you'll be taking most of the dash out to replace the expensive evaporator! (BMW have a special tool for this job which has a drill depth stop built into it.)

 

The evaporator is contained in a plastic housing with an outlet at the bottom to allow condensate (water) to drain to the outside when the A/C is working hard. Small dribbles or tiny puddles of water below the car are often signs that condensate is draining away correctly. You need to be careful to not drill your hole too close to the bottom of this plastic housing since you don't want condensate draining into the car.

 

The hole is used to poke one of those flexible plastic pipe extensions that come complete with A/C cleaning aerosol like this one:

 

http://www.amazon.co.uk/Liqui-Moly-4087-Climate-Control/dp/B001CZKC4G/ref=sr_1_2/276-7093050-5905943?s=automotive&ie=UTF8&qid=1438363566&sr=1-2&keywords=liqui+moly+cleaner

 

Location of the evaporator:

post-52803-0-69719800-1438364670_thumb.j

(Above) In the front passenger footwell behind that carpetted trim panel. Remove the phillips head screw & washer then slid the trim panel toward the seat.

post-52803-0-82725300-1438364797_thumb.j

(Above) I drilled a hole just about opposite that bracket.

post-52803-0-88485300-1438364919_thumb.j

(Above) Bought a handful of these rubber plugs from eBay for a couple of quid but you only need one. Notice how the tapered design of the plug allows for a snug fit. I think I drilled a 16mm hole. Really important when drilling not to let a disk of plastic drop into the bottom of the evaporator housing since there is some potential for it to block the drain hole.

post-52803-0-52268900-1438365175_thumb.j

(Above) I use this stuff and spray it in and around the evaporator with a lance attached to one of those garden pump sprayers.

 

Once you've finished cleaning the evaporator fit a rubber plug/bung to seal the hole up. The plug makes repeat cleaning of the system a lot quicker.

 

Well worth spraying the anti-bacterial cleaner into the cabin air intake system (with the fans running) by removing the plastic 'trumpets' that direct air from the cabin filters through the bulkhead into the cabin. Spray with a fine but generous amount of mist. Change the cabin filters & clean the cabin filter housing with the stuff as well. Spraying into all the cabin air outlets is also well advised.

 

I do this cleaning job once a year on my E39s.

Is this still the approved method? Mine smells like blue cheese.

 

ive seen someone suggesting to take off the intake snorkels in the engine bay side and use the Lance to spray the other side of the evap too.

 

does anyone know where the drain is and if it’s possible to clean it out?

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Don't think you can get to the evaporator through the snorkels, the blower fans are in the way. The drains open above the transmission, have bends in them and are hard to get to without the car on a lift. Hence the drill method above.

 

There are other things to try though. Basically the smell is caused by a buildup of mold that thrives on the moisture collected on the evaporator, once the AC is switched off the moisture evaporates and the smelly bits come out with the airflow. You can attack it chemically by using one of the smell bomb cans but (don't bother with the spray nozzle ones, use the ones you set off in a sealed car with the AC on recirculation). Ozone does much the same.

 

Sometimes just depriving the mold of moisture by driving without the AC for a while works too. Drive around for a bit with the AC off (preferably on a dry day) so all the moisture has a chance to evaporate, switch heater to max for a bit and then park the car. The hot air flow won't hit evaporator directly but radiant heat from the heater core may still be enough to kill it.

 

 

Edited by Carlton

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An electric ozone generator avaialble for under £50 will get rid of the smell and kill surface bacteria but probably won't reach the evaporator tray. Make sure you leave the doors open for a while after the machine has switched off though. You don't want to breath in ozone.

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