What exactly is a microfilter for? From what I see it's to with some sort of air filtration etc, but how does it work? The reason I ask is that the service interval on the I-Drive screen for the microfilter is dropping in mileage at least twice as quickly as the oil, brakes etc. The oil has shown 6000 miles remaining for a good while now (more than 1000 miles) and the microfilter has dropped from 8000 to 5000 in the same space of time. Is there any reason why this is happening, anything I should look for?
Purpose of a microfilter?
- Thread starter 5tephen
- Start date
![[TW]Fox](/data/man-of-honor/2009.png){kind=avatar}
Microfilters are designed to general capital for BMW franchised dealers. A BMW 3 Series has one Microfilter, but the 5 Series has two becuase it is considered that their owners will be better off, and thus able to donate more money to the local dealer.
BMW recommends that BOTH microfilters are replaced every 10 minutes (or at every service), at a cost of £50 - included in the service for E39's.
In reality, you can get BMW not to bother with changing them, save £50 on your service, and either buy both from GSF for £16 or simply vacuum them. Not sure how you do that with the E60 though given iDrive tells you about them.
BMW recommends that BOTH microfilters are replaced every 10 minutes (or at every service), at a cost of £50 - included in the service for E39's.
In reality, you can get BMW not to bother with changing them, save £50 on your service, and either buy both from GSF for £16 or simply vacuum them. Not sure how you do that with the E60 though given iDrive tells you about them.
Changing frequency (in reality) is dependant on environmental factors, cars used in heavily polluted cities and in high dust areas should be cleaned or replaced at regular intervals. In the UK as Fox says above it is a way to add £50 onto your service. My dealer told me not to bother with the microfilters at every service and to change them every two or three years.
As Fox said, it sounds like a simple way for BMW to make an extra £50 out of you come service time.
Assume they are basically a cabin air filter? If so, I've never replaced one on any cars either me or my parents have owned, simply vac'd out the old one, comes up good as new.
Assume they are basically a cabin air filter? If so, I've never replaced one on any cars either me or my parents have owned, simply vac'd out the old one, comes up good as new.
I leave the computer for 4 days and my question gets flushed away down the pecking order 
Thanks for the replies. (10 minutes
) One way or another I'm going to have to do something about it because I-Drive insists so.
I'm assuming it's more than just a pollen filter? Does it filter anything emitted by the car? My particulate filter burns off quite often and I used to think it was related to that. The particulate filter shows 100,000 miles remaining and I thought the microfilter was like a pre-particulate filter or something.
The pollen filter on the old Merc was only changed once every 2 or 3 years. What confuses me is how the mileage remaining is dropping at a considerably higher rate than the other features. I've been in quite a few traffic jams and piddling around the city for a while but not every day, traffic here in NI is nowhere what some of you guys get in Engerland.
The thing is I'm not overly bothered but I'm all for learning about these things of course
Thanks for the replies. (10 minutes
) One way or another I'm going to have to do something about it because I-Drive insists so.I'm assuming it's more than just a pollen filter? Does it filter anything emitted by the car? My particulate filter burns off quite often and I used to think it was related to that. The particulate filter shows 100,000 miles remaining and I thought the microfilter was like a pre-particulate filter or something.
The pollen filter on the old Merc was only changed once every 2 or 3 years. What confuses me is how the mileage remaining is dropping at a considerably higher rate than the other features. I've been in quite a few traffic jams and piddling around the city for a while but not every day, traffic here in NI is nowhere what some of you guys get in Engerland.
The thing is I'm not overly bothered but I'm all for learning about these things of course