gherb

i just changed my stock airfilter to a k&n high flow air filter (model # E-1009). i noticed in the airbox and on the intake itself that there is a bypass hole above the intake and in the airbox allowing unfiltered air to enter the engine.

what is it for? and why would GM let dirty air into the engine? is it better for me to just remove the airbox and cover the bypass hole that's located above the filter?

BlulytesTB

Ok... here is what I found.

The intake tube (for lack of better wording) has this hole. Why? I don't know... however...



If you look at the top of the airbox, where this opening fits into is a sealed compartment on the top of the airbox. It does not let dirty air into the intake after the filter. So, no need to worry all!



Any questions, let me know!

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2004 Trailblazer LT

gherb

i could have sworn on the airbox itself, it attached to that bypass (two holes on the top of the airbox that formed a crevice to which air can flow 'around' the filter). also, will i get more airflow if i just remove the airbox all together and cover up that bypass with some duct tape?

lt2000

I have noticed this hole also.I believe it was for a no longer used air restriction gauge.Also the oem air filter is/was the cheapest piece of junk i have ever seen on a new car.
gary

dach95

You still need something to block the heat from the engin from going back into your intake cause your engine to heat up more.

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2002 Chevy TrailBlazer 4X4 LTZ EXT Summit White
4.2L I6, 3.73 rear diff ratio K&N HighFlow KN-1009 air filter Airaid Throttle Body Spacer Sylvania Silverstar Lows 9006ST
Infinity Burl Wood molded dash kit In-Channel VentShades 35% front windows.

Excellent source of info http://www.trailvoy.com

lt2000

Dach95,
the hole in the air box is a vacuum chamber.in other words it doesn't have an opening at the other end.It should have been eliminated when they quit installing the air filter restriction guage,but the will cut every corner they can.However you could install a guage yourself if you wanted one.I don't think they are very helpful except on diesel engines.If yhe rubber seal stays intact it will not leak,if however the seal goes bad then dirty air will enter at that point,which is not good.
gary