Here is the simple procedure to follow in order to replace the Bmw 3-Series E90 Pollen filter (also called Cabin Filter) on the BMW E90 series (2005 onward).
All Pollen Filters for 3 Series 2005 onwards model (Model Code E90,E91,E92,E93) are the same. It is advisable to replace the pollen filter with one which is ‘carbon coated’ as provide better filtration.
First, simply open the bonnet and locate the air filter housing, which is found towards the back of the engine compartment, just below and in front of the windscreen.
It is a long rectangular shaped black plastic housing approximately 832mm x 20mm x 132mm. There are six T20 torque screws that fasten the top of the plastic housing to its mounting.
You will need to loosen these screws first, with a suitable torque driver, in order to remove the housing from the mounting and gain access to replace the cabin air filter.
Two of the T20 torque screws are found on the front edge of the casing, one at either rear corner of the housing and two more on the back edge of the housing – after removing all six screws you can pull the housing up and out from its resting position and remove it from the vehicle.
You will now see the light coloured filter inside the casing and this can be released by undoing the three latches located along the edge of the casing.
Inspect the casing for any sign of damage such as cracks or splits and clean the inside of the casing if necessary. Unpack and insert the new filter – there are three hooks on the lower edge to locate the new cabin air filter and then snap the three latches into position to lock it into place inside the housing.
Once the new cabin air filter is in place you can align the casing with the mounting and after making sure that it is positioned well – lock it in place with the six T20 torque screws to secure it to the mounting again.