Rotten egg smell from ventilation system?

[Polome]

Hi my Polo GTI is seventeen years old but still under 40k miles. The last few weeks a rotten eggs , foul smell has been coming into the cabin from the heater vents. It happens both when asking for hot or cold air( ac off & on ) . All the functions of the ventilation system appear to work fine I.e. AC , fan , flaps etc. Read that bacteria build upon evaporator can possibly cause this so I've run a couple of spray conditioner cans through the system . It's reduced the smell but it's still there. Anybody had this and found a soloution. Thanks in advance. Ian

[Trev450]

More than likely to be bacteria in your A/C system. Have it regassed and all should be fine.

[Rick101]

I'd check the battery too.

Once had an egg smell in an old 406 and found the battery swollen up like a balloon!

[cuprabob]

Sulphur smells like rotten eggs so double check you catalyst is not leaking and the fumes are getting into the cabin.

Bacteria in the aircon / ventilation system tends to smell more like sweaty trainers / mould / damp dog. If it is bacteria, take it to an air con specialist and have it sanitised.

[Rich_W]

Trev450 said:

More than likely to be bacteria in your A/C system. Have it regassed and all should be fine.

What the actual fk!


Bacteria on the AC evaporator is nothing to do with how much gas is in the system.

Internet forums make me and sometimes!

if you're happy it's not bacteria build up check for other sources of the smells and that the AC isnot just drawing it in.

Plastic bag stuck to the exhaust etc

[Duke of Kidderminster]

Farts maybe?

[Dr G]

Trev450 said:

More than likely to be bacteria in your A/C system. Have it regassed and all should be fine.

The bacteria/dirt/smell will be from somewhere within the fresh air tubes/pipes/passages rather than the refrigerant itself. The refrigerant and fresh/heated/cooled air never mix. A new pollen filter and aerosol disinfectant should sort this.

Edited by Dr G on Thursday 4th May 14:56

[Trev450]

Dr G said:

Trev450 said:

More than likely to be bacteria in your A/C system. Have it regassed and all should be fine.

Or a marginally more constructive version of the above:

The bacteria/dirt/smell will be from somewhere within the fresh air tubes/pipes/passages rather than the refrigerant itself. The refrigerant and fresh/heated/cooled air never mix. A new pollen filter and aerosol disinfectant should sort this.

A much more helpful response than some of the others!

Edited by Trev450 on Thursday 4th May 14:53

[Trev450]

Rich_W said:

Trev450 said:

More than likely to be bacteria in your A/C system. Have it regassed and all should be fine.

What the actual fk!


Bacteria on the AC evaporator is nothing to do with how much gas is in the system.

Internet forums make me and sometimes!

A simple 'not quite accurate' statement would have sufficed!

Edited by Trev450 on Thursday 4th May 18:39

[anonymous-user]

I had a similar smell - it was coming from my screenwash bottle. Worth a check

[Polome]

Hi. To close out post...needed 3 applications of sanitizer spray and a new pollen filter. So all well now and have a ( very ) sweet smelling car. Many thanks for the replies regards. Ian