Additional information at http://www.unofficialbmw.com/e36/int...crofilter.html WARNING: Do NOT buy the ebay filters as they do not have the small ledges that allow the filters to snap in and lock into place!
Additional Note: the "air baffle" (thin, breakable plastic piece seen below) is part number: 64 11 8 369 186 FOIL
Originally contributed by Brian Brown
I replaced the microfilters on my ti this evening. I didn't recall seeing the procedure for the ti described on the net before, so here goes:
The microfilters help clean the air coming into the car's passenger compartment.
The 318ti (E36/5) has a different procedure for changing the microfilters than the other E36 cars. Instead of gaining access through the passenger compartment, the filters on the ti are accessed under the hood.
The good news: The ti's microfilters are probably easier to replace than the other E36's.
The bad news: Because the ti uses two filters, it's more expensive (I paid about $40 for two).
Microfilter BMW part#: 64 11 8 363 274 (two required).
Tools required: #2 Phillips screwdriver. 7mm nutdriver.
Open the hood.
There is a mesh grill near the base of the windshield. Press on the three locking tabs and pull the grill up.
Remove the two Phillips screws that are now exposed. These hold a plastic wire channel assembly that is under the air intake. Pull forward on the wire channel assembly to free it up.
The large cover that these two screws passed through is called the air collector.
On the drivers side of the air collector is a 7mm hex head screw going into the firewall. Remove it.
On the passenger side of the air collector are two more 7mm screws to be removed. These are kind of hidden behind a bellows coming out of the end of the wire channel. I found it easier to get a nutdriver on the upper screw by removing the battery cover.
The air collector now should be removed. This is the one part that's kind of tricky. It's a tight fit and a bit of a puzzle. By pulling the wire channel forward and moving the air collector from side to side while tipping it, the air collector will come out.
Now visible is a thin plastic air baffle. Pull up a couple inches on the ends of the two hood gasket strips so this baffle can be removed.
The service manual says to remove the two microfilters, frames and all. I found it easier to leave the frames in place.
The microfilters will pull out by lifting at their edges.
I was surprised by how much dirt had been trapped in mine. It helped convince me that these serve a useful purpose.
Installation is basically the reverse of removal. Pay attention to the following points:
When installing the new filters into their frames, run your finger along the entire edge of the filter to make sure that it's fully seated.
When replacing the thin plastic air baffle, make sure the top lip wraps around the edge of the sheet metal.
When replacing the air collector, sneak and wiggle it in like when taking it out. The lower and driver's side edge of the air collector fit into a grove. Start at the driver's side and work around. Start all three of the screws before tightening. Make sure that nothing is getting pinched behind.
Make sure that the back edge of the wire channel engages with the tabs on the air collector before replacing the two screws.
When replacing the intake mesh grill, guide the rubber gasket over the front lip of the grill.
This job is fairly simple, but it does require some pretty good manual dexterity.
I think it beats paying the dealer to do it.