Air Filter Indicator

jhm · July 30, 2004

The air filter change indicator on my truck and everyone else I talk with who has one, has never changed from the green to yellow or red. With GM stripping out needed things like interior lighting, no foot rest, etc why waste money on a totally useless feature? Has anyone actually seen the indicator change? I changed my filter at 29k and the indicator was still in the green. How clogged would the thing have to get to go to yellow or red???? I bought my truck with 13k on it so I don't know if it was changed earlier, but I doubt it.

Greek · July 30, 2004

You know I noticed the same thing. I change the air filter every year or so, but what good is the indicator? It does not even move slightly which makes one wonder what good it is.

seadoons · July 30, 2004

I agree. I have never understood exactly what it is supposed to do, because it never does anything! I change out my air filter every 15K.

citydriver · July 30, 2004

Fleets have more use 4 them to keep maint. costs down,takes the guessing out of it....They are also real usefull in "dusty" regions of the country such as the South West..they typically measure resistance/restriction in inches of H2O,the higher the retriction of the filter the more vacuum that is created behind the filer element, sorry if I'm rambling about stuff you may already know...

intruder217 · July 30, 2004

When you changed your filters did you see any obvious improvement in mileage or performance that would lead you to believe that the old filter was clogged?

asilverblazer · July 30, 2004

I saw a definite improvement in mileage. I think my indicator was green, I don''t remeber but I tried to reset and nothing happened.. nor has anything sense. I think GM got the idea from a ricer or something, I think the indicator adds 10 hp too.

jhm · August 2, 2004

When I replaced my filter at 30k, it did not appear overly dirty, I think for the indicator to move it would have to be essentially totally blocked with crud. I would just keep changing it every 10-15k depending on how dusty it gets where you drive. Dont wait for the indicator to move.

99-2door · August 2, 2004

Pop the indicator out and suck on the end. You will see how little pressure it actually takes to trip it over.

I think the filter needs changed before that thing flips, but it does have a purpose.

jhm · August 2, 2004

Like I said initially, the thing is a waste of money because mine was still in the green at 30k. All they need to do is put the changeout mileage or time in the manual. I think people who do thier own maintenance will not wait for the indicator, nor would a garage, so it is a waste of money. Give me something useful like a driver side footrest for the same money. Even my wifes Civic has one, it makes a difference on highway trip. Just my .02

Valsport · August 2, 2004

I've never seen my indicator change whatsoever. I do not have a set cycle that I change my air filter because I do very different types of driving throughout the year. I spend a fair amount of time in west texas where is really sandy and dusty all the time, and the other part of the year I spend in north texas where conditions are pretty ideal. Every once in a while I'll pop the cover off the air box and have a look at the element, and I change when needed. Ive seen it pretty gunked up before and the indicator did't move a milimeter.

Rapiti · August 7, 2004

I saw a definite improvement in mileage. I think my indicator was green, I don''t remeber but I tried to reset and nothing happened.. nor has anything sense. I think GM got the idea from a ricer or something, I think the indicator adds 10 hp too.

Mine has a Type R sticker. I get 20-30 RW HP on my rice dyno

04-silver · August 7, 2004

Just a thought here.

Actually I don't know if this would even work but anyway for those who have already changed their air-filter, why not try to block/restict the flow somehow on the old filter, (clean) dense rag maybe and put it back in a see what happens with the light indicator.

One could probably just do this to the filter thats in there now really, unless you have something better to do......lol

John

jhm · August 9, 2004

The thing that bugs me is they waste money on the stupid indicator and then use cheap plastic on important things like the license plate lamp holders. I was washing my truck with a sponge and the cheap plastic tabs that hold the housing into the bumper broke off on one lamp. Makes you wonder what thier engineering dept is thinking about priorities.

chris_kucia · August 9, 2004

Two things about air filters:

1) GM, and most automakers, significantly oversize their filters so they aren't a restriction to the system, even when dirty. Look how much filter fabric is in that huge square. Then look at the throttle body hole. As long as that filter can flow enough air to supply the throttle body, then its not a restriction.

2) The amount of air that needs to pass through the filter is proportional to the RPMs of the engine. If your typical driving never pushes the engine close to its maximum RPM, then your filter can be pretty dirty with no adverse effects. OTOH, if you're doing a lot of towing (particularly using tow/haul mode) where you need power and high-rpms, then a dirty filter can be a big problem.

The owner manual doesn't indicate that the engine needs to be running to check the indicator. This would imply that it is set to trip open at a certain vacuum level vs atmospheric pressure - likely when RPM's are high enough to generate airflow requirements that come close to overwhelming the filter.

So, if you don't routinely drive your truck hard, your dirty filter will likely be more than adequate. If, however, you do drive it hard, then you'll trip the indicator in time to change the filter before you hamper performance.

Its not as sophisticated as the oil life indicator, but it seems to do a good job of tailoring filter change intervals to the type of driving the owner engages in. This keeps filters out of landfills and keeps frugal owners from changing their filter unnecessarilly. The manual says to check it twice/year or when changing oil, so there must be a pretty hefty buffer built in.

Personally, I wouldn't wait until the indicator trips, because my driving, although pretty mild, is punctuated by intervals of intense towing/hauling. I would rather have a clean filter beforehand, then wait until I stress the engine enough to trip the filter indicator. However, if your driving is consistent, especially the case with a fleet or a "working truck", then the filter could save money over the long haul, especially in high-mileage or dusty situations.