double air filtration

[crw]

My daughter and her husband, just married a few months ago, went out to buy their first car. I thought they made a great deal on a 2012 Hyundai Sonata. I was a little concerned at the GDI engine, and then got a lot more concerned when I saw that the previous owner had put a K&N air filter on it!

I tossed the K&N on the concrete and a bunch of crud came out. In my mind I'm saying, "Why?, Why???". (I'm one who believes that these re-usable air filters let too much dirt pass...) I offer to buy them a new paper filter. My new son-in-law is a great kid but not at all tuned in to mechanical things. So I get back with the paper filter, and after taking the air box apart a little more I notice that there is a second, "permanent" air filter inside the air box. It says "Do not remove" in English and Korean. Perhaps all is not lost? The second filter looked to be in decent condition.

Anyway, I put the paper filter in and hopefully they will get their moneysworth out of this ride. I hadn't seen a double air filter before.

 

[901Memphis]

That sounds cool. It might be a rock catcher though just to prevent engine damage if the main filter is damaged. I don't suppose you got any pics of it or could see how fine the material is or what it could be made of? Probably some sort of foam i would imagine.

 

[crw]

It was more like paper and I didn't think to take pictures. There were visible dots on it, it probably doesn't filter the finest particles.

 

[Tomioka]

That is the hydrocarbon filter which is common in later model Toyotas and other makers are probably catching on to reduce emissions. It's supposed to prevent fumes from escaping through the airbox/air filter by trapping the vapors between the HC filter and intake manifold.

 

[horse123]

Originally Posted By: Kibitoshin
That is the hydrocarbon filter which is common in later model Toyotas and other makers are probably catching on to reduce emissions. It's supposed to prevent fumes from escaping through the airbox/air filter by trapping the vapors between the HC filter and intake manifold.


What he said ^

Also lol @ thinking k&n is junk. Been running mine for a year in all kinds of conditions, and my intake behind the filter still looks like it just came out of a clean room.

 

[OneEyeJack]

Being better than treated paper for air filtration is difficult at best. If the K&N flows better it must be at the expense of the quality of the filtration process. For a daily driver that might just be a bad trade off. Especially with computer controlled devices in the path of the air flow I would think that staying stock for a DD would be the safe bet. Most users of the K&N that follow instructions probably never have a problem but with the cost of repairs one time is enough to think about staying with the stock setup.

 

[crw]

Hmmm... my own experience with them is that, before using my oil would always be clear when it came time to change it. (This was years ago...) Then after beginning K&N usage, my oil became murky, darker, etc. I then switched back, and few OCIs later I'm clean again.

I tend to think along the lines of this guy:

https://www.youtube.com/watch?v=NJKlb61_kXU

 

[crw]

Originally Posted By: OneEyeJack
Being better than treated paper for air filtration is difficult at best. If the K&N flows better it must be at the expense of the quality of the filtration process. For a daily driver that might just be a bad trade off. Especially with computer controlled devices in the path of the air flow I would think that staying stock for a DD would be the safe bet. Most users of the K&N that follow instructions probably never have a problem but with the cost of repairs one time is enough to think about staying with the stock setup.


That's my thought. These are metered air, basic transportation vehicles, not drag racers. I can't see how a K&N helps performance on a Sonata, but I can suspect that it will allow dirt inside.

 

[crw]

Originally Posted By: Kibitoshin
That is the hydrocarbon filter which is common in later model Toyotas and other makers are probably catching on to reduce emissions. It's supposed to prevent fumes from escaping through the airbox/air filter by trapping the vapors between the HC filter and intake manifold.


I wish it was still there so I could look at it again, but it was literally like two air filters, one stacked on the other, when put together.There is no escape or bypass that I noticed. Air must flow through both. Are we talking about two different things?

Or, are you saying that it's some sort of "backflow prevention" type of device? For air?

 

[901Memphis]

Originally Posted By: horse123
Originally Posted By: Kibitoshin
That is the hydrocarbon filter which is common in later model Toyotas and other makers are probably catching on to reduce emissions. It's supposed to prevent fumes from escaping through the airbox/air filter by trapping the vapors between the HC filter and intake manifold.


What he said ^

Also lol @ thinking k&n is junk. Been running mine for a year in all kinds of conditions, and my intake behind the filter still looks like it just came out of a clean room.



They are junk in many of our opinions. What is the job of an air filter?...it is to filter first and K&N is flat out inferior to oem paper style filters.

I saw a fine dust test where the K&N was only 96% efficient vs over 99.9% of an AC delco oem filter. Air filtration is far more important to engine wear than oil filtration although I value both to a different degree.

Plus we have seen used oil analysis of vehicles that had a K&N installed showing elevated wear metals accompanied by increased silicon which is unfiltered air. The un filterd air gets into the oil and acts like sand paper inside the engine bearings.

Oem engines without modifications have no ability to use extra air flow over oem paper filters. Maybe if you are running a modified supercharged V8 I could see the need for more air flow but without everything else to go with it your air filter is not the largest point of air flow restriction in the engine.

 

[Wolf359]

Plus fine oil droplets get on the MAF which can screw it up, the unknowing either end up replacing a dirty MAF from the K&N oil or you have to end up cleaning it. That's more from people who use too much oil when re-oiling their filter. K&N really does nothing, the car runs at a fixed air/fuel mixture.

 

[Tomioka]

Originally Posted By: crw
Or, are you saying that it's some sort of "backflow prevention" type of device? For air?


Yep and to absorb fuel vapors and other HC's similar to a fuel tank charcoal canister when the engine is off. The reason it's not removable because it's part of the emissions equipment. It's a common mod to remove them in a lot of the yota forums I go to.

 

[horse123]

Originally Posted By: crw
Originally Posted By: OneEyeJack
Being better than treated paper for air filtration is difficult at best. If the K&N flows better it must be at the expense of the quality of the filtration process. For a daily driver that might just be a bad trade off. Especially with computer controlled devices in the path of the air flow I would think that staying stock for a DD would be the safe bet. Most users of the K&N that follow instructions probably never have a problem but with the cost of repairs one time is enough to think about staying with the stock setup.


That's my thought. These are metered air, basic transportation vehicles, not drag racers. I can't see how a K&N helps performance on a Sonata, but I can suspect that it will allow dirt inside.


Performance isn't the only point... it's a lifetime filter for $50... saves tons of money over the years.

Originally Posted By: Wolf359
Plus fine oil droplets get on the MAF which can screw it up, the unknowing either end up replacing a dirty MAF from the K&N oil or you have to end up cleaning it. That's more from people who use too much oil when re-oiling their filter. K&N really does nothing, the car runs at a fixed air/fuel mixture.


Not even remotely true. The only way to get oil past the filter is some idiot overoiling their filter after they clean it.

 

[gaijinnv]

Originally Posted By: crw
Originally Posted By: Kibitoshin
That is the hydrocarbon filter which is common in later model Toyotas and other makers are probably catching on to reduce emissions. It's supposed to prevent fumes from escaping through the airbox/air filter by trapping the vapors between the HC filter and intake manifold.


I wish it was still there so I could look at it again, but it was literally like two air filters, one stacked on the other, when put together.There is no escape or bypass that I noticed. Air must flow through both. Are we talking about two different things?

Or, are you saying that it's some sort of "backflow prevention" type of device? For air?


Here's what it looks like on my 5.7L Toyota motor:

In top of air box:

In situ:

Gratuitous picture of installed filter minder:

HTH

 

[rrounds]

Well that gauge will be easy to read. Good spot for it, don't forget to tell us how many miles you get out of the filter.

ROD

 

[wemay]

Originally Posted By: horse123
Originally Posted By: crw
Originally Posted By: OneEyeJack
Being better than treated paper for air filtration is difficult at best. If the K&N flows better it must be at the expense of the quality of the filtration process. For a daily driver that might just be a bad trade off. Especially with computer controlled devices in the path of the air flow I would think that staying stock for a DD would be the safe bet. Most users of the K&N that follow instructions probably never have a problem but with the cost of repairs one time is enough to think about staying with the stock setup.


That's my thought. These are metered air, basic transportation vehicles, not drag racers. I can't see how a K&N helps performance on a Sonata, but I can suspect that it will allow dirt inside.


Performance isn't the only point... it's a lifetime filter for $50... saves tons of money over the years.

Originally Posted By: Wolf359
Plus fine oil droplets get on the MAF which can screw it up, the unknowing either end up replacing a dirty MAF from the K&N oil or you have to end up cleaning it. That's more from people who use too much oil when re-oiling their filter. K&N really does nothing, the car runs at a fixed air/fuel mixture.


Not even remotely true. The only way to get oil past the filter is some idiot overoiling their filter after they clean it.



+1

I have no illusions of my Corolla gaining HP from it.

 

[circuitsmith]

Originally Posted By: horse123
it's a lifetime filter for $50... saves tons of money over the years.


Unless the dirt it lets through trashes the engine.
An oem air filter for my car costs $13, an air restriction gauge cost $17.
Current filter has 39k miles and less than 11" of restriction.
If I change the filter at 50k miles then over 150k three filters cost $39.
I can afford the total $56 to guarantee my engine is getting clean air.