Air Filter Replacement

Every 20,000 kilometres or so, you should change the air filter in your BMW. The air filter protects the fuel injection system and the air intake system from dust and debris that can be sucked in under normal operation.

     On the E30 BMWs, the air filter is contained in a bubble-like housing that is located in the front left side of the engine compartment.  Removal of the filter is accomplished merely by lifting the scraps and prying up the cover.

On the E36 cars, the filter is located in a similar spot, however, it's now mounted vertically 

Step 2

(Step 2).  Simply pull up on the top cover 

Step 3

(Step 3), and the filter should come right out of its housing 

Step 4

(Step 4).  Take a look inside the filter housing - there are usually some leaves or dirt that found their way in there.  Clean the housing out before installing the new filter 

Step 5

(Step 5).
     For the BMW 3-Series there are basically two different types of air filters—the stock paper or cloth air filters and aftermarket units. These aftermarket units utilize an oil-soaked fabric to achieve freer air flow 

Step 6

(Step 6). The bottleneck for air flow in the BMW engine is not necessarily the air filter. The primary advantage of the aftermarket units is that you usually only have to purchase one, and it will last the life of your car. The downside is that they often do not filter as well as the factory units.  The bottom line is to carefully research any aftermarket filter before you install it to your car. I personally prefer to use the stock OEM cloth/paper filters to ensure maximum filtering.  Whichever one you choose, make sure that it filters as well as or better than the original BMW specifications for your year car.