Bad smell when aircon is on

[buxbunny]

Hello happy Skoda owners,

 

The winter is over and recently i turned AC on again ( after a pause of 4-5 months ). The bad smell is unbearable. It's like there is a dead animal in the ventilation system. Although there is no bad smell when I use only the ventilation.

Do you know what part of the ventilation system is used only when AC is turned on ?

Thank you for your help.

 

[JD52]

It's possible that bacteria have developed in the AC system and this can be removed using an Aircon Cleaner Bomb. You can get one from Halfords.

 

From past experience these work very well.

 

As a thought, it is probably better to leave the AC switched on all the time and this issue won't occur.

 

[ahenners]

As above, can vouch for the air con bomb solution which should clear it up. Bought one from Euro car parts last time.

 

Definitely wise to use your air con frequently, I only ever switch mine off if windows are open.

[buxbunny]

Thanks for the advice.

To keep air conditioning on all the time is not a solution in my case.

Is Octavia having this issue more frequent than big sister Superb , VW or Audi ?

 

[bertJ]

Hope you don't mind me asking but why wouldn't you leave the air con switched on all the time?

[RickW]

We leave it on all the time in our Fabia and Citigo and they never mist up in the winter.

[Mallettsmallett]

Unfortunately, you'll get the same issue each year unless you run it all year round. It's designed to be on permanently. You'll also get issues with the reliability as the compressor and pressure lines need running and the gas has lubricant in it.

 

The smell won't be completely eradicated as the smell is bacteria on the evaporator often, and the fragrance just makes the system smell nice temporarily but doesn't get to the root cause unless you get the evaporator cleaned properly. Even using an enzyme based bomb doesn't clean it. It just masks the smell temporarily. 

[Gabbo]

As others have said you should leave the AC button on all the time to prevent this.

The system only engages the compressor for cooling when its needed so in the winter it will just condition the air, remove moisture etc which should prevent things like this happening. It also helps greatly the de-misting in the winter.

 

After 3 years and 4 winters I have no problems with the AC system having left the system on since I bought it.

 

My experience in older cars is also like MallettsMallet, once you have a problem with bateria/smell its very difficult to get it to go away & the bombs only work for a few weeks/months before the smell starts to return.

[JD52]

@buxbunny, Could be worth going to Halfords, or somewhere similar, who offer an aircon bacterial clean.

 

The advantage is that the cost isn't too much, about £20, but you would have some comeback if the smell returns.

 

[Phil-E]

The air con "bombs" you can get work very well.

 

Our Octavia developed a bad smell even with regular use (although it was a cold winter to it likely didn't kick in much then).

 

My advise is to remove the pollen filter when using it. You then turn the fans on full, recirc on, A/C on max (coldest temp) and all vents open and trigger it behind the passenger seat.

 

No more smells after that.

 

I tried the cheaper ones you just spray down the vents and they just masked the smell temporarily.

[buxbunny]

Thank you all for explanations.

Then I will go for apermanent fix and have the evaporator cleaned.

[Orville]

My aircon started smelling a few months ago so I set-off an air-bomb and replaced the cabin-filter. All is now fine.

[octavia5]

I would caution against getting the Halfords own brand - they do sell others - unless you want to be stuck with an overwhelming scented car - the smell to me is like a very cheap perfume and it took 4 months to clear.

[Phil-E]

I went for the Normfest one. It's not scented.

 

It stinks (like a strong chemical/clean smell) but not scented with anything and the smell soon wears off.

[Mallettsmallett]

Odour bombs didn't work for me. The only think that really helped was this

 

http://www.micksgarage.com/ProductDetails.aspx?pid=886115

 

But you have to be careful with the pipe and it's pot luck getting it fully inserted.

 

 

And, to be brutally honest, even if you get the evaporator unit cleaned manually, you will have this problem if you run it intermittently. Best leave it off permanently if you are not going to keep it on.

Edited 4 April, 2017 by Mallettsmallett

[Orville]

I used one of these https://www.amazon.co.uk/gp/product/B007C6Q6XA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

[themanwithnoaim]

The only reason to turn the AC off is......

 

TO GET MORE POWER

[Rodge]

I used to leave the aircon off for months at a time in my old Focus and never had a problem with smells. What might help (and save a small amount of fuel) is to turn the aircon off a few minutes before you finish your journey to allow the evaporator to dry out. The aircon on the Octavia is supposed to operate very slowly all the time to keep the seals lubricated. But definitely remember that the aircon is for dehumidification as well as cooling.

[Gabbo]

On ‎04‎.‎04‎.‎2017 at 13:25, themanwithnoaim said:

The only reason to turn the AC off is......

TO GET MORE POWER

 

When you boot it, the AC compressor is automatically disabled by the ECU to give max power for overtaking.

[johnrowley]

had the same problem, smelly aircon, in a range rover, turned out to be a squirrel storing acorns for the winter

[toni8b]

On 4/4/2017 at 10:35, Phil-E said:

The air con "bombs" you can get work very well.

 

Our Octavia developed a bad smell even with regular use (although it was a cold winter to it likely didn't kick in much then).

 

My advise is to remove the pollen filter when using it. You then turn the fans on full, recirc on, A/C on max (coldest temp) and all vents open and trigger it behind the passenger seat.

 

No more smells after that.

 

I tried the cheaper ones you just spray down the vents and they just masked the smell temporarily.

How do you access pollen filter, is it under the steering wheel?

[Phil-E]

Not entirely sure on the MK3. But on the MK2 it was in the passenger footwell (UK) so maybe under the wheel yes in a LHD car.

[toni8b]

I shall ask the hedgehog.

[James@RRG_Skoda_Rochdale]

The pollen filter is behind the glove box and can be accessed by removing the glove box lid.

 

Just so everyone is aware - the mk111 Octavia (and most modern cars) use a variable displacement type compressor. This means it turns even when the A/C button isn't pressed, the only difference that's made when the button is pressed is the capacity is adjusted and increases which alters load on the engine (minutely). 

 

People dont seem to understand that it's a conditioning system for cabin air. It dehumidifies the cab during colder, damper months which prevents condensation and cools the air using the same meathods during the warmer seasons. 

[spinifex]

I'd like to know how this thinking translates to those of us in the southern hemisphere?

Here in Australia, it's humid during summer, not winter.... and I don't know anybody who runs their AC all year round.

 

I regularly run mine both in summer and winter, and my ventilation fan is ALWAYS on even if the AC is off.... so plenty of time for the evaporator to dry out rather than just shutting down and causing bacterial growth.

 

I've only owned my car for 6 months, and I do a lot of windows-open driving.

 

Recently, I've noticed my air smells like rotten socks, when first turning the AC on after a period of inactivity (even with the fan constantly running)

I know this is the bacterial smell often explained as being caused by just turning the AC AND fan off and not drying out properly, which is definitely not the case in my situation.

 

The whole "leave the AC running permanently" thing is new to me here..... most people only use the AC during the hottest of summers.

 

Thoughts?