Musty Aircon Smell on Switch On

[grpar]

Anyone else get a burst of musty smelling air from the aircon when it's first switched on (and for about 20 seconds thereafter) ?? I've tried the Comma Aircon Cleaner which kept the smell at bay for about a week.

Could it be the pollen filter that needs changing ? (I live next to Kew Gardens and get plagued by fluffy air-borne pollen in the spring / summer).

(p.s. Before you're tempted to ask it, the smell is not me. I am hygenic.)

 

[television]

This would appear to be a clogged pollen filter, do check that it is all clear including the one in the box under the windscreen

 

[mr. serious]

If the smell is like BAD smelly socks then this is probably more likely to be the reason than anything else... I had this problem in my m5. Found the same answer on the m5 forum I was with back then, but cant remember the exact cause and rectification method, so I googled it!!

http://www.whatcar.com/news-special-report.aspx?NA=216531&EL=3136438

Hope this helps, as it worked for me.

Ian

 

[Phil D]

same problem on mine (W203 saloon) - where exactly is the pollen filter & is it an easy / cheap job?
any advice would be more than welcome
thanks

 

[MBNuB]

On my W203 Estate, the pollen filter covers the battery at the nearside rear of the engine bay. I assume the saloon has it in the same place?
It's secured by 3 over-centre clips which are a bit of a fiddle to detach. But only the first time you do it...

I had a similar problem in my car recently. The filter turned out to be OK, but there was a problem with the stepper motor controlling A/C airflow in the middle of the dash. This manifest itself as a clicking/tapping noise each time the car was started up.

The filter's a nice easy one to check first, though. Fingers crossed.

 

[Phil D]

thanks Clive - I've had a look and there is a big filter over the battery - looks in pretty good nick to me though - don't have any funny noises either - maybe if the filter's not too dear I could try a new one anyway - it is 3 years old after all
Phil

 

[grpar]

Clicking Noise

MBNuB,

I also have a metallic clicking noise coming from somewhere in the dash on the driver's side. It's quite quiet but fairly rapid (about 6 clicks a second).
Was this the same as your problem ?

 

[itass]

Smelly Aircon

Hi - i have the same problem - tried the comma spray and changed pollen airfilter with a new one. Still get the musty smell. I now spray the front vents with a household air freshiner to disguise the smell at start up - this does work - but would prefere to fix the problem rather than using a work around - any one have any idears ???

 

[grpar]

Checked the pollen filter

Checked the pollen filter box above the battery as MBNub described. Little dusty inside but otherwise in good condition, and certainly not blocked. The impeller you can see behind the filter box looks absolutely brand new aswell. Anyone ever mentioned the musty smell to their MB dealer before ?

 

[MBNuB]

...fairly rapid (about 6 clicks a second). Was this the same as your problem ?

No. Mine was a series of 10-12 clicks over as many seconds, just when I first started the car. After those clicks it stopped. The A/C man told me it was the stepper motor trying to reset itself, presumably going from one extreme of adjustment to the other.

The gears on the stepper motors are prone to breaking, apparently, and MB sell a kit so the gears on all the stepper motors behind the dash can be replaced when the first one breaks.

I'm afraid I've no idea what yours might be, grpar.

 

[BlackC55]

This is a common problem that MB are aware of. The evaporator builds up bacteria that cause the smell.

There is a recomended repair that dealers are aware of.

Its a big job (dash out) and expensive if you have no warranty.

Take it to a specialist and half the cost!!

 

[Phil D]

Hi
I've got a few months left on warranty - from your post it sounds as if I might be covered - is that the case ? (he asked hopefully) & if so is there anything in particular I should be mentioning when I contact the dealers - as I mentioned in a previous post - had loads of cars with aircon (including mercedes) - never had this issue before
thanks
Phil

 

[BlackC55]

Just mention a smell that makes you feel sick and unbearable and they should do somthing about it.

 

[Phil D]

will do (entirely truthfully) I'll let everyone know howe I get on - thanks

 

[Phil D]

Update as promised - BlackC55 you were spot on
I had the car in at the dealers today - not my usual one but they are new, more convenient & certainly seemed keen to please
they had the car all day & when I went back to collect it the service manager said that there had been some "instances" of smelly aircon & as a result MB had a procedure to follow - I think he called it an FF3
anyway he showed me a flow chart of lots of things to try - couldn't see the detail but he mentioned checking filters, running it on hot for 2hours!!! then cold etc
After that if the smell seemed to have gone they have to return the car to the owner
However he did go on to say that if the smell came back the next step was "basically to replace everything" which meant dash out etc - he said he would have been happy to do it all but if he did so now he would not get paid by MB.
Asked me to keep using the aircon over the next few days/weeks and if the smell came back he'd happily book it back in & sort it - and that if it was going to go wrong again it was likely to do so fairly soon - hope he's right
I guess I'm lucky that I've still got a bit of warranty left, but if you have and you've got smelly aircon I'd get right into the dealers & asked them to fix it
big thanks to BlackC55 - hope it's permananently fixed now, but if not I know ahat to do
Phil

 

[grpar]

thanks Phil

Mine's booked in for 16 July, as that is the first day I don't need the car. Slight pain in that my local MB dealer in Brentford W.London doesn't give out courtesy cars for "investigation" work; they only provide them during normal A & B servicing. I sense after (nearly) 3 years with MB that I will be going only to a BMW showroom next time.

 

[BlackC55]

Mine's booked in for 16 July, as that is the first day I don't need the car. Slight pain in that my local MB dealer in Brentford W.London doesn't give out courtesy cars for "investigation" work; they only provide them during normal A & B servicing. I sense after (nearly) 3 years with MB that I will be going only to a BMW showroom next time.

A specialist will be able to do the job at half the cost of a dealer. its long winded but do-able

 

[grpar]

Did the fix work PhilD .... ??

Wondering if the MB fix worked on your aircon, i.e run it hot for 2 hours .... ?

 

[jp williams]

The smell will more than likely disappear if at the end of each journey you run the air con on hot for approx 5 mins so as to dry out the sytem and eliminate the bacteria.
Le t me know how you get on as it wotks for me.
Regards
JOHN

 

[Phil D]

Hello again
It did go away - at first ! This morning I was sure I got a slight whiff when I set off to work, and then tonight, after a day sitting in hot sun there was no doubt - same old pong, ok it went away much quicker than before, but presumably it will get worse again. I'm going to contact the dealers again tomorrow and ask if they will be able to replace the offending bits under warranty.
As far as the various posts which suggest running on hot for the last five minutes to dry the system out - ok it may work but why should it be necessary??? I"ve never had this problem with any previous car (including an earlier C Class)
Based on the dealer's attitude last week I'm reasonably optimistic, but will keep you posted