www.taligentx.com - Collections     Thursday, June 8, 2023
home|passat|maintenance & repair|Cabin Filter Replacement

Cabin Filter Improvement/Replacement


The cabin air filter's function...well, take a wild guess. :)

The main gripe I had with the filter is the expense of the activated-carbon treated filter (around double the OEM cost of the plain filter), considering that this "special treatment" is a small amount of activated carbon sprinkled in the pulp mix. Fortunately, the space given to the filter is enough to allow some design improvement.

Part Information & Sources:

Note - always confirm part numbers by looking at the actual part mounted in the car! Mistakes will happen sometime, somewhere.

Part numbers:

Plain filter
'98-01 8A0 819 439 A
'01.5-05    1H0 819 644 A

Carbon filter
'98-01 3B0 091 800

OEM Pricing: ~$35-$40 ($65-$75 HEPA/carbon)
Impex: $19 ($30 HEPA/carbon)
Adirondack: $19
A Volkswagen Part: $15 ($27 HEPA/carbon)

Filter removal:

The cabin air filter is located on the rear passenger side of the engine bay, behind the firewall. (illustration)

  1. Start by unscrewing the single philips screw visible.
  2. Pull out the filter lid - this piece prevents water from flowing onto the filter, as well as directing airflow. (illustration)
  3. To remove the filter, lift the exposed portion up and pull out at an angle. (illustration)
  4. Take a flashlight and look into the filter housing - some leaves may have fallen into the blower duct during removal. Pull out anything you see that isn't plastic, unless you enjoy the whirring sound of leaves being blown around (I have a friend who does, actually).

After two years and 30,000 miles, this filter had served its useful life. (illustration)

At this point, you can either stop here and just pop in the new filter, or if you like to live dangerously, keep reading...

Activated carbonization:

  1. Swing by your friendly neighborhood hardware/general store and pick up a carbon prefilter designed for use with home HEPA filters. Home Depot carried a generic cut-to-fit Honeywell sheet for around $10. Fairly thin stuff (1/8"), but far more useful than the combo cabin filter/carbon mix.
  2. Cut one or two pieces to fit. Using two pieces per filter, you should have enough carbon to make three more carbon changes, or seven with a single piece.
  3. Attach the pieces to the filter. If using one piece, attach to the top of the filter. Note inelegant use of duct tape...ah, well. (illustration)

    Using the carbon as a pre-filter is preferable because a) carbon particles that shake loose will fall into the main filter instead of being blown into the cabin, and b) carbon sheets are far less expensive than the paper filter. The carbon sheet will catch quite a bit of material itself and should extend the useful life of the paper filter.

  4. Reinstall the new improved superfilter you've just created. Be careful when reinserting the filter - it's a pain enough with the paper filter alone, the carbon sheeting just adds to the joy. Have a helper pull on the plastic gutter above the filter housing, this should give you enough room to slide the filter into place without scraping too much of the carbon sheeting. Properly positioning the filter requires some filter acrobatics, don't be afraid to bend the filter slightly to get it into place and completely seated down.
  5. Take additional care when reinstalling the plastic filter lid. Push the lid upward (using a hand underneath) as much as possible when sliding it over the carbon sheeting to keep from catching the sheeting and moving it aside. The lid fit fine even with a layer of carbon above and below the paper filter.

All done! Take your baby out for a drive and smell that carbon freshness. The blower motor is more than powerful enough to deal with the added load of the carbon filters - there was no notable change in airflow with two pieces in place. The replacement interval on the carbon for home use is around three months, though the useful life in this application will depend on your area. The OEM carbon filters are spec'd for yearly replacement.


  • Hi, does anyone know any mechanics in the Berkshire, UK area who can resolve the CCM problem due to water in footwell causing intermittent alarm going off problem? Thanks.
    Anwar, United Kingdom - Jun 10, 2016 @ 6:21 am
  • The carbon filter add-on for the cabin filter is cool. Thanks for the tip. Works really well!
    Sameer Verma, San Francisco, CA , USA - Jun 11, 2010 @ 2:47 pm
  • My \'01 Passat doesn\'t have the cabin air filter cover, the black plastic piece covering it. Do you know the part number for that? How important is it? Maybe that\'s why our AC doesn\'t blow very hard--air isn\'t directed correctly.
    Brian - Mar 11, 2010 @ 10:07 am
  • Thanks alot! i have cleaned something else which is the throttle and i observed, felt and enjoyed a great difference! and i\'ll try the cabin filter as well.
    kareem, Canada - Jul 6, 2009 @ 9:07 pm
  • Thats brilliant, all good usefull info complete with Pics ! I will try this myself today. Thanks
    John - Ireland - Feb 10, 2009 @ 5:31 am
  • Well done, you beat the heck out of Chilton\'s
    Doug-USA - Dec 9, 2008 @ 7:00 pm
  • All GREAT write ups!. In addition to the cabin air filter replacement , I used your procedures/ illustrations to great advantage in replacing my transmission filter and repairing my passenger door lock cable, as well. You have saved me some serious $$$. Can\'t thank you enough!
    Cal- Virginia, USA - Oct 23, 2008 @ 6:05 pm
  • Ah! What a pleasure of NOT being taken advantage of by THE SYSTEM. Thanks! On my way to Home Depot or Lowes. I will try it on my wife\'s SAAB as well.

    Gregory Kumor - Aug 17, 2008 @ 11:24 am
  • I got a 7 year old used Passat. I think this was the first time the filter had been changed. Mine looks twice as gross as yours, with a nice pile of leaves and bugs layered on top AND more crammed into every crevice. Thanks for the clear photos and description.
    Brent Thompson USA - May 9, 2008 @ 3:15 pm
  • Great Stuff! Just bought this car used and need to catch up on some of these things. Best description I\'ve seen. Thanks again!
    Doug - Dec 3, 2007 @ 7:24 pm
  • My car looks different under the hood. It is a 2002 but no area like your picturefor the filter, it\'s a 4 cylinder. the mold in my car is giving the family sinus infections that never go away. please help. Any other areas we could look to get rid of allergens?
    Paul - Jul 8, 2007 @ 7:45 am
  • Thanks for all the great tips!
    James(Canada) - Feb 18, 2007 @ 12:23 pm
  • could you write a little bit more about the difference between the standard filter and Carbon filter? The info I got is that carbon filter (cost $25-30) brings better air quality.
    Is this right?
    Andrew, AZ, US - Jan 27, 2007 @ 2:51 pm
  • great writeup! Thank you very much for sharing the info.

    Andrew - Jan 27, 2007 @ 1:54 am
  • Thanks for the Tips-It works great
    Clem-CA, USA - Oct 17, 2006 @ 12:49 am
  • Thanks! - Perfect instructions.
    I got my filter from 2nd vw dealer for $18. 1st one wanted $38 (what a ripoff!) Don\'t pay more than $18 for a standard one, You should be able to find a wix,fram,or bosch filter at local auto parts store if dealer is too much...ben
    Ben - PA, USA - Aug 4, 2006 @ 12:41 pm
  • Interesting tip and greeaaat info. I am going to try this out. Is the engine air filter modify going to be the next write up?
    Tee - Aug 6, 2005 @ 2:51 pm
  • Wow, great illustrations/write-up, I\'ve never done any maintenance on my car other than taking it to the quick lube, and I really want to change the cabin filter myself...I think this is really going to help, thanks!
    Jennifer - USA - Jun 23, 2005 @ 5:24 pm
  • Thanks for the tips.

    Take care,


    Don W - Jun 8, 2005 @ 3:07 pm
  • Great write up (this one and others on the web site). Please add more and more writeups and help other DIYers.

    BA - Apr 19, 2005 @ 1:13 am
  • Why does my 2002 NOT have a filter cover? Water pours into my cabin!
    Jason - Mar 28, 2005 @ 10:52 am
  • any picture to locate the oil filter?
    Henry - Jan 15, 2005 @ 10:30 pm
  • Should get you on your way.

    Stephen - Jan 5, 2005 @ 8:39 pm
  • Can you show how to change the engine oil fliter? thanks a lot
    Henry - Dec 5, 2004 @ 12:37 am

Add a comment:

name (and country would be nice to see)
email (optional, not shown publicly)