So yesterday my microfilter went down to O miles and needed to be changer. I had not ordered the replacements yet and wanted to inspect them so i opened both sides and found them to be fairly clean. Put them back in, closed everything up and went on line to look for replacements. by the way should i stick with OEM(mann) or is there something you guys have used that is as good quality? Anyway after driving this morning i did not get the "Idrive Chime" and after looking closer my microfilter said i had 1400 miles to go! I guess ill let it go till o again. Have you had this experience?

 

I ordered two Mann charcoal activated cabin filters and a Mann air filter on Amazon, with shipping for $59. Seemed to be the best price i could find for OEM.

 

I have experienced the miles to go for the oil change increase after driving, but have not noticed it on other items. The service deadlines are condition-based, so maybe there's some algorithm that increases the microfilter interval. Can't imagine what it would be. I doubt the car knows you inspected them.

 

Sometimes the really inexpensive microfilters ( you can find them on ebay for $20 or so) are only pleated paper without the charcoal filters that are supposed to remove / reduce odors.

 

If they're not dirty take them out and blow them off. Clean them gently and look at your ducts. Spray some disinfectant spray around the ducts for a minute while it's their out and your air is on and grabbing outside air. Spray the shit out of your filters and reinstall and enjoy the scent lol. BMW vents are known for bacteria build up so just do it. There is a TIS bulletin about this "smell" the filters smell new or old but if they're old you'll really notice if the AC is off.

As far as ur situtionn the chime was yellow warning chime. it will be red in 1400mi and you'll have to reset anyway.