Really dirty air filter element

[Dennis Nicholls]

I just changed out the air filter element on my car. I was shocked to find a layer of ground up leaves on top of it (black foam side), and after I got the old filter out and turned it over a huge amount of fine dirt was expelled. My vacuum cleaner fortunately was able to get all the stuff out of the lower (downstream) chamber. This filter was a genuine Porsche part with date code of 03-06-11 (presumably European date 3 June 2011), so the filter had been changed in the last couple of years. CarFax says air filter changed 11 July 2011, mileage 48,708.

The mileage is now at 51,580. How in the heck did the filter element get so dirty/full of debris in 3K miles? Is this typical for the Boxster design, with the air intake exposed through the car body at the side?

[JFP in PA]

I just changed out the air filter element on my car. I was shocked to find a layer of ground up leaves on top of it (black foam side), and after I got the old filter out and turned it over a huge amount of fine dirt was expelled. My vacuum cleaner fortunately was able to get all the stuff out of the lower (downstream) chamber. This filter was a genuine Porsche part with date code of 03-06-11 (presumably European date 3 June 2011), so the filter had been changed in the last couple of years. CarFax says air filter changed 11 July 2011, mileage 48,708.

The mileage is now at 51,580. How in the heck did the filter element get so dirty/full of debris in 3K miles? Is this typical for the Boxster design, with the air intake exposed through the car body at the side?

Your problem is exactly why I laugh when people spend a lot of money for aftermarket "cold air" intakes for these cars. The Boxster air intake setup pulls in cold air from the driver's side port, along with anything else that happens to be near by (leaves, dirt, debris, small children, etc.). Depending upon the type of roads you drive on, annual or even semi annual filter changes are an excellent maintenance item. The filters are cheap, readily available, and easy to change; we use the Wix/NAPA Gold 42475 which retails at auto parts stores for about $16.

[Dennis Nicholls]

My car sat on the dealer's lot for much of the past two years....maybe some clueless groundskeepers with leaf blowers blew crud into the intake.

I used a Mann C2558/5 filter, which is $15 at RockAuto. Looks just like the genuine Porsche filter, perhaps Mann is OEM. Both stamped made in Austria.

The Boxster air filter box is unlike any other car's that I've owned. Normally the bottom of the box is the upstream (dirty) side. On the Boxster the bottom of the box is the downstream (clean) side, and when you slide out the dirty filter any debris on top gets scraped off and falls down into the bottom of the box.

Edited February 22, 2014 by Dennis Nicholls