"Rotten egg" type smell

[sattyb]

Hi,

I have a 2019 530i. I've noticed that when I turn on the car I get a rotten egg type smell from the air vents. This lasts for a little while and then disappears. If I press the external air button (to allow the external air in) when I start the car the smell is not as bad.

This has led me to believe that maybe it's mould etc built up in the air conditioning pipes that is causing the smell (I may be wrong but I hope someone can point me in the right direction).

I have tried activating the auxiliary ventilation when I swith the car off so the fan run when the car is switched off. This makes a little bit if difference in that the smell is nowhere as bad when I restart the car but its still there initially.

How do I getting rid of this smell?

Thanks in advance.

[worsy]

Rotten Eggs could be the cat or at least a sensor attributed to it.

[d_a_n1979]

sattyb said:

Hi,

I have a 2019 530i. I've noticed that when I turn on the car I get a rotten egg type smell from the air vents. This lasts for a little while and then disappears. If I press the external air button (to allow the external air in) when I start the car the smell is not as bad.

This has led me to believe that maybe it's mould etc built up in the air conditioning pipes that is causing the smell (I may be wrong but I hope someone can point me in the right direction).

I have tried activating the auxiliary ventilation when I swith the car off so the fan run when the car is switched off. This makes a little bit if difference in that the smell is nowhere as bad when I restart the car but its still there initially.

How do I getting rid of this smell?

Thanks in advance.

Rotten eggs is usually cat related, as stated above

But it could be aircon...

Do you have it on all the time, as you should?

If not. Get an aircon refresh kit off Amazon, ie: Autoglym AS150 Air-Con Sanitiser, 150ml https://amzn.eu/d/8Mxau8z

Use that, refresh the system and leave it on all the time after that so it stays in rude health and keeps smelling fresh

[DirktheDaring]

Rotten egg smell on a caravan/motorhome is often the first sign of a dead/dying battery, I know it’s a BMW but worth a quick check over.

[996Type]

Could also be the window wash bottle, mine went off on my old BMW and needed a good clear out. Drop Milton fluid in there and run a few cycles of Frau water through it to eliminate that as a cause….

[sattyb]

Many thanks for all the replies and information. There are no warning lights on the dash and as the smell dissappears after around 5 mins I thought I'd check the windscreen washer fluid.

I opened the lid that you open to fill it and thought I'd see if I could smell anything and it was the same rotten egg smell.
I've totally emptied it, refilled and emptied again. I've them refilled and I think it may have been the cause. I've left it for tonight and will see if the smell reappears in the morning on start up.

Thanks again for all the helpful advice and I will (hopefully) report back tomorrow with good news.

[sattyb]

I thought I'd give you helpful people an update. I've driven the car today and there is no more smell coming out if the vents so I think it was the windscreen washer fluid.

The car has been turned off ans started a couple of times so far this morning and all seems good. Thank you all again for the advice.