Is Slight Dust/Dirt on the Clean Side of Air Filter Normal?

[daveatthebill]

Hello everyone,

Two weeks prior, I installed a new air filter in my vehicle, ensuring it was correctly seated and the airbox was tightly secured. I did not drive the vehicle much in the past two weeks, Maybe a maximum of 30 minutes over the last 2 weeks. Today, while doing some engine work, I removed the airbox for better access and inspected the filter. The bottom side (dirty side, where air enters from outside) was visibly dirty, as expected. However, I noticed some small dust/dirt particles scattered on the top side (clean side) of the filter media. There weren’t many, but they were noticeable. The bottom side was definitely dirtier.

I thought the clean side would remain completely free of dust, with the filter catching all particles on the dirty side before air reaches the engine. Is it normal to have a slight amount of dust or dirt on the clean side of the filter, or should it stay completely clean? For context, the filter was spotless when I installed it.

Since an air filter has two sides, I refer to the bottom side as the side where outside air enters into and the top side of the filter where air does not enter, it is more for the air to exit into the TB.

Any insights would be appreciated! Thank you

 

[carviewsonic]

Filtered side of intakes on different vehicles has always been dust free as far as I can tell.
Carefully check intake duct for cracks, and if all good then try a different brand of filter.
I’ve learned to buy air filters from the dealer for best fit. Sometimes aftermarket don’t fit properly.

 

[V70tdi]

Tell more about your driving environment. Dusty desert or something like that ? In 2 weeks with so little driving the filter would look like new here in Sweden.

 

[Lubener]

You got poor sealing somewhere. Either at the filter or at the joints for the air intake plumbing.

 

[Kira]

Year, make, model, trim level (engine size) seems always to help.

I noticed some small dust/dirt particles scattered on the top side

You noticed a FEW PARTICLES....which were scattered.

Sounds like a FEW PARTICLES fell from the intake air handling tubes. Your car might be 15 years old with 135k on the odo.
While not preferable, a bit of dirt falling out of said ductwork might not be any big deal at all.

REMEMBER: All systems leak!

As suggested above, it's always good to make sure your large hoses are fit correctly and not split.....though the resulting incoming air leak would likely trip a warning light.

I bet previous ownership installed a less-than-perfect fitting air filter which dirtied your intake air hoses after the filter (clean side).

What you do is take a wadded-up bunch of rags made from an old plain white undershirt, moisten it and run it through the intake hoses and see how much dirt sticks to it. I bet the dirt you find will match the dirt on your AF's clean side.

Heck, on two cars in a row, slob servicemen didn't even fit the airbox lid on correctly resulting in one of the three hold-down latches to break.
You gotta know people are careless and frequently spiteful in this world.
I mean seriously, how much care and attention does one need to ensure a flat filter is seated correctly?