911RufRT

I also noticed one side blows harder than the other.

Pete Lech

When the AC is on, the outside air is turned off. So where would the pollen come from for the filters to catch??? If you use your AC the majority of the time, and are not smoking in your car, the filters should last a very long time.

Getting the covers back on is a royal PIA, so once you are in there looking around, you might as well replace them. Better to just leave them alone, IMHO.

JimGinKC

I replace mine every 15k, and they're pretty dirty at that point. They're cheap, and relatively easy to replace, however lining up the little tab can take more than one try.

Leander

I'll replace mine only if the car starts sneezing.

kilodawg

I've had the car for 7 years and never changed them. It was pretty much a weekend car for the ex and living in Florida my AC is always on....Since my divorce though the 993 has become my daily driver and so I'm staying on top of every little detail. I think they were just a bit dirty.....

Changing them was an easy 15 minutes from start to finish and that was taking my time and cleaning up a bit as well. There is a trick to it and I really think that worrying too much about the top tab makes it harder. There are two other tabs molded into the circumference of the filter on either side (you can see them in the picture below) and if you seat the filters properly all you need to do is slightly rotate the filter until the outboard tab rests right against the slot in the housing (so you can't rotate it any further and then insert the cover. Done this way the alignment is set, the cover slides right on and the lower clips snap in place.

They have to have been the dirtiest thing on my whole car.....

911Dave

I adhere to the maintenance schedule religiously, which includes changing the pollen filters. Replacement is simple, there's not trick to it at all. You just have to look at the housings and understand how the cover fits over the lip of the filter. Most of us are so meticulous about every other aspect of our cars that it seems incongruous to ignore such an easy and inexpensive item of regular maintenance.

Ed Hughes

Why defer maintenance? They do take a little fiddling, but the process is fairly simple.

Mike J

I pull mine out, blow them out with compressed air, and put them back in.

I tend to drive with my windows and sunroof open, so what the heck is a pollen filter doing for me? I figure its only good to keep the internals of the HVAC system cleaner.

Cheers,

Mike

NP993

For every mile you drive with a dirty pollen filter, God kills a kitten.

kilodawg

No more kittens on my watch.....

Rinty

Say it isn't so...

Opo

The first time I replace mine , I didn't put the cover back right , so I notice that the car a/c was warmer than usual, so I let my heavy equipment mechanic put a can of freon , it was still warm, so it took it to a a/c guy and he told me that my guy put too much freon, so he said he had to dry the unit and put new freon, I told him ok, car got done and it was still warm, so after spending $300 we figured out that I didn't put the covers back correctly all that to say that please make sure you put those covers back correctly.

Leon993

For me its about environmental quality. I want to breathe the cleanest air possible.

IXLR8

The rate at which the cabin filters clog and get dirty will be a function of their use. I drive with my windows up as it makes a world of difference as to how often I need to clean the inside of my cars.

Replace them when they get dirty. It is an ultra easy task on our 993s.

This is a cabin air filter on my daily driver after almost 5 years. I tend to forget to replace them because they aren't easily accessible. Reduced heating/AC air flow is a reminder.



A bit of a difference; a new cabin air filter...

ToSi

Anyone able to find an activated carbon version of these? Here's the 9x6/7 version: