[Wissam]

I've searched the owner's manual and there is no mention of engine air filter...I also looked in my service records from the dealer and again no mention of them replacing the engine air filter...where is it covered? how are we supposed to know when to replace it?

[tibra1]

open it up and look at it to see if its dirty..the only way.

[Wissam]

So does that mean that the dealer never replaced it during the 4-year free maintenance program, because there's no mention of it on service records! isn't it odd that it's completely omitted in the owner's manual?!

[pruettfan]

My dealer says every other oil change.

[tibra1]

They never replaced mine..it wasnt even that dirty when i put my new intake on..but thats b/c my car has low miles..and i dont drive in dusty areas..

just open it up it like 6 clips..very easy to do..how many miles r on ur car?

[tibra1]

Originally Posted by pruettfan

My dealer says every other oil change.

Thats over kill IMO..rule of thumb every 3 yrs is good..unless u r driving in back roads ...dusty desert roads..etc

[Wissam]

my car has ~60K km...there is this DIY that says you have to remove the whole housing (bottom half of first page)...

http://www.e90post.com/forums/showth...ght=air+filter

[tibra1]

woops my bad dude...didnt realize i was on the 328 forum..lol..yeah i saw the DIY it super easy

the 335 is just 6 clips..either way tho give it a shot..i dont know how mechanical u r but it really shouldnt be hard

60K kilometer is about 40K miles..so yeah i would say ur about due for a change..if ur under warranty make the dealer change it..but tell em u want the old filter so u know they did it

[StoneCold]

Originally Posted by Wissam

I've searched the owner's manual and there is no mention of engine air filter...I also looked in my service records from the dealer and again no mention of them replacing the engine air filter...where is it covered? how are we supposed to know when to replace it?

Originally Posted by Wissam

my car has ~60K km...there is this DIY that says you have to remove the whole housing (bottom half of first page)...

http://www.e90post.com/forums/showth...ght=air+filter

45K miles.

[dunit]

Originally Posted by pruettfan

My dealer says every other oil change.

My Dealer said the same ,but changed it at the third oil change, after I questioned them.

[ENINTY]

The service book states to change the engine air filter at every 3rd oil change. That means every 3rd BMW oil change interval of 15,000 - 17,000 miles, which translates to evry 45,000 - 51,000 miles.

[SilverII]

at 9K mine was filled with tiny leaves, sand and junk. I took it off and dusted all that crap off and reinstalled

[pruettfan]

Originally Posted by tibra1

Thats over kill IMO..rule of thumb every 3 yrs is good..unless u r driving in back roads ...dusty desert roads..etc

I live in AZ the dust capital of the world.

[tibra1]

Originally Posted by pruettfan

I live in AZ the dust capital of the world.

Well now i understand..ur dealer is prolly correct..and it so easy to check anyways..sometimes even pulling it out and give it a good wack..to shake off the junk on it.

[tntsE90]

Once a year, regardless of mileage. The filter is less then $20 and can be replace quick.

[Wires]

Originally Posted by Wissam

So does that mean that the dealer never replaced it during the 4-year free maintenance program, because there's no mention of it on service records! isn't it odd that it's completely omitted in the owner's manual?!

I put a K&N in mine when I bought it. The car has 36,000km on it (38 months), and it's still clean/fine. I've never washed it yet.

So most likely for a car, it never gets touched in the 4 year maintenance program (unless you do a lot of gravel road driving, which most people probably avoid in a BMW....)

[roundle]

Just checked mine for the first time, after 4.5 years and 81K miles.

As expected, it was the original, factory air filter from May 2010. All things considered, it was in decent shape: No leaves or physical debris.

While I had the air box out, I decided to rip out the charcoal filter. It felt brittle and I was slightly concerned that it might fail and suck charcoal dust into the engine.

[sippinblkgold]

Embarrassingly, I've just checked my air filter for the first time in 7 years and about 55k miles. Low and behold, the previous owner had a K&N in there - I had no idea. I put in a MANN filter.

How likely is it that this caused any damage? I know a K&N which hasn't been oiled in so long won't trap the smaller particles, but I'm not sure about the real effects of leaving a filter un-oiled and unchanged for so long. I don't drive especially dusty or dirty roads, so the filter actually didn't look too bad.

Should I clean and oil the K&N and throw it back in or run the MANN for a while?

[Phil325i]

K&Ns are reckoned to be good for 50K between clean/oil so you should be fine. I'd say clean and oil the K&N. But you'll get the usual naysayers queuing up to say your K&N will be the ruination of your MAF and the end of life as we know it...

[Three_thirty_I]

I actually replaced the air filter in mine earlier this year when it was due for a service, and the last time it had a new air filter was back in 2012. In my case, I don't do very high mileage, so the "old" filter was actually still very clean. As for the correct interval, I am not really sure either, will have to see if I can find anything out about that. Mine has the Euro type intake, so it's the cylinder type filter, so it was a bit pricey but insisted on the OEM filter. In general I do inspect air filters and use a vacuum cleaner to clean any visible debris that might be in the air box and on the filter element itself. It's kinda like the cabin filter, depending on how much the car is used, and the dust conditions, lifespan will vary, so a service interval is probably not so easy to set.

[Gohan335i7]

Once a year for sure ...