Filter

[turbotak21]

What filter is the best? iv got a k&n at the mo, already on the car when i got it, Any good?

[330ciSport]

If your talking standard air-box filter then it doesn't really matter tbh.

Your going to get feck all out of paying above the cost of OEM (assuming it's cheaper than K&N etc).

[turbotak21]

No its an induction kit but iv heard bad things about k&n filters.

[330ciSport]

I've got a K&N Typhoon on mine. Can't say I've had any issues with it in the 3 years it's been on the car.

What have you heard that's put you off and why do you feel the need to change?

[turbotak21]

Thats the filter i have. Iv heard the k&n filters dont work as good as others and over time let in more dust as say apexi or hks.

[330ciSport]

Thats the filter i have. Iv heard the k&n filters dont work as good as others and over time let in more dust as say apexi or hks.

Well, I personally wouldn't agree with that but can't say I've done much testing. I take the filter off regularly and haven't seen any evidence of nasties between filter and MAF. Just make sure the filter is well oiled and maintained and you shouldn't have any issues

[turbotak21]

What do i use to clean it? any special stuff?

[RoRu]

K&N sell cleaning kit, which contains a cleaner and oil.

Their a good filter as long as you don't oil it too heavily, people think the more oil the better the filtration, this is what causes problems.

If you soak the filter in oil some of the oil ends up on the MAF causing false readings, the ECU then leans the fuel mixture out too much which you really don't want.

[330ciSport]

What do i use to clean it? any special stuff?

Pop down to your local Halfrauds and get the K&N Filter Charger kit. It consists of a can of cleaner and a can of oil (red in colour).

Take the filter off the car. When doing this be VERY careful not to drop any of the bolts (you will probably have to undo the bracket bolt to get the filter out). This very important. The underside of the M3 is sealed and if you do drop them, they don't pop out on to the floor.

You'll have to man handle the filter a bit to get it out, just don't damage the filter itself.

Once off, spray with the cleaner and wash under luke wram water. I repeat this until no dirt washes out, it will be obvious. Then, let it dry naturally. Don't force it (i.e. hairdryer) and it's best left over night.

In the morning, give it a liberal coating with the spray oil. A couple of times over will do to get good coverage and you'll see the filter "turn" red. Damp down any excessive bits and lets stand for a bit. As RoRu says, don't plaster the thing in oil. Then, yer good to go.

They say do it every 8,000 miles or so but I do it every 3 months just to be safe. It's if you don't follow this procedure damage can take place so I hope you haven't done many miles since you bought it :confused:

[peppernick]

Their a good filter as long as you don't oil it too heavily,

If you soak the filter in oil some of the oil ends up on the MAF causing false readings
That's the key.

Sometimes, too much oil on the filter element and you can potentially damage your MAF meter.

[turbotak21]

Only done 2000mls, only had the car in march. Thanks for the help, think il go halfords now lol:)

[330ciSport]

Only done 2000mls, only had the car in march. Thanks for the help, think il go halfords now lol:)

LoL. Wouldn't worry anyway.