How dirty is dirty?

[snoboy]

How often do you change air filters? Do you wait till mileage begins to deminish. Do you change at a certain number of miles? Do you change annually? How much dirt is visually in the filter when you change?

snoboy

 

[MN Driver]

I used to change mine once a year which last year that came out to 10,000-15,000 miles. The filter never looked dirty enough to be restricted but I changed it anyway thinking that better gas mileage would be beneficial and I didn't know that filters actually filtered better once they were a little dirty but I know better than that now. Since it's very very rare that I drive in dusty conditions such as dirt roads, I think that the 30k GM recommendation is plenty and as with 15k miles looking pretty clean and only about 1/4 of the media shows any visible 'dirt darkening' it seemed obvious that the path easiest traveled was not changed due to any dirt restriction. I'll have to double check with my Toyota manual but I think it says to replace my air filter every 15k miles and since the 1.8 liter 7AFE engine in that thing runs at high rpm's it will probably be plenty dirty by then so it will get changed at the recommended interval. I spent $10 per filter and I figure that if that lasts a year that price isn't much of an issue and I suppose thata if UOA's start showing increased silicon or insolubles in my oil I will take that as the clue that the air filter is done.

 

[m2200b]

Every other year around 20k. IMO I'm not going far enough since they're not real dirty then so I use 2 years to be sure I get far enough.

 

[jmacmaster]

How long a filter lasts depends on a number of things, including the type and size of the filter, where its placed in the engine compartment, how much of it is exposed to air, and how much you drive on dirt, gravel, and off-road. For a number of years, I had 79 Dodge pickup and a 90 Dodge pickup that I drove interchangeably in my neck of the woods, mostly on pavement, with some driving on gravel roads. The 90 Dodge was bought new and went over 50,000 mi. before the air filter got dirty, mainly I believe because of where it was placed in the engine compartment and the fact that it was inside an airbox. The air filter in the 79 Dodge was the old, round, type, with a big hole in the middle, that fit in a metal container that sat on top of the carb and the container had a funnel coming out of it. That was the traditional setup on the old, carbed, engines. That air filter consistently had to be replaced every 2,000 to 3,000 miles.

For a paper filter, I knock it against a hard flat surface till dirt stops coming off. Then I hold it up to the sun to see how easy it is to see through it. Then I see if I can gently breath through it. If I can see through it and easily breath through it I figure its still good. But, if your engine's not running right after you put the air filter back on, change the filter.

 

[ziggy]

i was taught the same as jcmaster, take the filter out and if youcna still see somehwat through it, then its still good. hwoever, llike everyone else jsut stated, it depends on miles and conditions. i jsut change mine every 2 years.but in 2 years i will have only like 15 miles. dont drve that much, with fram fitlers, after 2 years, theyy were pitch black! soot looke ike youde have to soak in solution or peel it off with a tough knife! thats how they alsways get in my car after 2 years. i am using an AC delco right now. next time, i am gunna try pureone, wix, or fram tough guard, havnt decided yet, maybe a NAPA. NAPA has more pleats; )

 

[otis24]

Can anyone post any comparison pictures? I drive 20k miles per year. I just checked my filter and it didn't really look too dirty. A few black streaks here and there.
Secondly, is it o.k. to clean an air filter by blowing it out? The most accumulation I have ever seen is a little dust and leaves/debris.
It really would be helpful to see a few pictures and see what you guys think is "dirty" and what you think is still servicable.

 

[vad]

I don't have a camera with me now but from what you describe (a few black streaks here and there) you've changed the filter waaaay too early.

 

[vad]

Dirty - needs to be replaced:

Not too dirty - is still good for many miles (requires just a 180 rotation):

Now guess this one:

 

[adam123]

Im suprised the top filter engine and the bottom filter engines still ran !!

 

[Matt89]

Any idea of # miles on the top one?

 

[ziggy]

only other thing i can thin of otis24, is you have a faulty, or crappy air filter. weh ni used reguarl fram air fitlers, after 2 years and 12- 15,000 miules later, it was black! not as thick as the last pic, lol oh my ***! but thick black adn sticky sooty. i am using an acdelco right now, and have been thiking, its not as good a quality. only reason i got it, was i read about it in thier website, and they showed a graph, avdvertising it cna catch up too 80% more particles. i know purolators, the regular paper media, used to not get as much recognition, and being not as sucha good quality fitler, as lets say, WIX, NAPA gold, or fram itself.
as for the top one i am guesing it has about 40,000 to 50,000 miles on it.

 

[ziggy]

lol as as uggestion, the bottom pic, that poor looking filter, take it out back, and put it outta its misery, persoanly i think its laready dead, lol. just needs a proper burial, or incinerator, for that matter.

 

[T-Keith]

Not sure why, but my filters never get that black scum on them. I have seen this on Fords and other cars, but not most GMs. Perhaps it has to do with the intake location.

So even if it's not that bad it may need to be replaced.

 

[cousincletus]

Haven't seen the black scum on Chrysler either. FWIW I drive my Cavalier in a dusty truck terminal yard and at 15,000 miles if I hold the filter up to the sunlight I can't see through it.