Engine Air Filters
#17
part of it is that many won't know that the aftermarket part MAY cause a problem until after the dealer runs the scam, or the mechanic tells the owner what the facts are. Once you have the knowledge you can do something.
I actually talked with a few engineers (one of them is a materials science engineer) because I found this particularly interesting. NONE of the engineers I spoke with believe the filters would or could cause a problem. The premise of every one of the engineers i spoke with, was the same. oil is not a corrosive. further, it should be a simple matter of cleaning the sensor.
thanks for the input everyone. I hope this information is helpful to someone else out there.
#18
Usually, over-oiled filters which deposit on the MAF have caused a lean condition in my experience. Still, doesn't hurt to take some proactive maintainence and inspect and clean the MAF wires with electronics cleaner.
I'd suspect the o2 sensors more than anything. Do you have a scanner capable of live data. You might be able to watch them live and help determine if they are slow to react. Also, taking a look at the long term and short term fuel trims may give you more clues. A good OBD2 scanner is a great tool in this situation
Do you have a CEL at all?
I'd suspect the o2 sensors more than anything. Do you have a scanner capable of live data. You might be able to watch them live and help determine if they are slow to react. Also, taking a look at the long term and short term fuel trims may give you more clues. A good OBD2 scanner is a great tool in this situation
Do you have a CEL at all?
#19
i never re-oiled my filter...
the check engine light might not even come on when your MAF is dirty.. the symptoms could be low/shaky idle when the car is warm, etc...
K&N works differently for different cars..
cars like G35 where MAF is so close to the filter will definitely have issues..
maybe people who proclaim "i've had K&N for 10 years without a problem..." is talking about their older hondas where MAF sensors or any sensors at all were not present between the filter and the throttle body.
dip ANY FILTER in oil/grease.. let it soak.. blow on it.. it's will go through..
unless a filter is designed to block 100% of the particles, there will be SOMETHING going through.. it's common sense... you don't have to be an engineer to understand that..
K&N is known to have inferior filtration level compared to a dry cloth/paper filter. AKA more/larger particles getting past it.
I am not saying that K&N is a killer to a MAF sensor..
all i am saying is that, don't be shocked if your MAF sensor is damaged or dirty. check for irregular idle (lower end)
the check engine light might not even come on when your MAF is dirty.. the symptoms could be low/shaky idle when the car is warm, etc...
K&N works differently for different cars..
cars like G35 where MAF is so close to the filter will definitely have issues..
maybe people who proclaim "i've had K&N for 10 years without a problem..." is talking about their older hondas where MAF sensors or any sensors at all were not present between the filter and the throttle body.
dip ANY FILTER in oil/grease.. let it soak.. blow on it.. it's will go through..
unless a filter is designed to block 100% of the particles, there will be SOMETHING going through.. it's common sense... you don't have to be an engineer to understand that..
K&N is known to have inferior filtration level compared to a dry cloth/paper filter. AKA more/larger particles getting past it.
I am not saying that K&N is a killer to a MAF sensor..
all i am saying is that, don't be shocked if your MAF sensor is damaged or dirty. check for irregular idle (lower end)
#20
i never re-oiled my filter...
the check engine light might not even come on when your MAF is dirty.. the symptoms could be low/shaky idle when the car is warm, etc...
K&N works differently for different cars..
cars like G35 where MAF is so close to the filter will definitely have issues..
maybe people who proclaim "i've had K&N for 10 years without a problem..." is talking about their older hondas where MAF sensors or any sensors at all were not present between the filter and the throttle body.
dip ANY FILTER in oil/grease.. let it soak.. blow on it.. it's will go through..
unless a filter is designed to block 100% of the particles, there will be SOMETHING going through.. it's common sense... you don't have to be an engineer to understand that..
K&N is known to have inferior filtration level compared to a dry cloth/paper filter. AKA more/larger particles getting past it.
I am not saying that K&N is a killer to a MAF sensor..
all i am saying is that, don't be shocked if your MAF sensor is damaged or dirty. check for irregular idle (lower end)
the check engine light might not even come on when your MAF is dirty.. the symptoms could be low/shaky idle when the car is warm, etc...
K&N works differently for different cars..
cars like G35 where MAF is so close to the filter will definitely have issues..
maybe people who proclaim "i've had K&N for 10 years without a problem..." is talking about their older hondas where MAF sensors or any sensors at all were not present between the filter and the throttle body.
dip ANY FILTER in oil/grease.. let it soak.. blow on it.. it's will go through..
unless a filter is designed to block 100% of the particles, there will be SOMETHING going through.. it's common sense... you don't have to be an engineer to understand that..
K&N is known to have inferior filtration level compared to a dry cloth/paper filter. AKA more/larger particles getting past it.
I am not saying that K&N is a killer to a MAF sensor..
all i am saying is that, don't be shocked if your MAF sensor is damaged or dirty. check for irregular idle (lower end)
please answer a question for me: Who states that the K&N air filter is inferior to paper ones?
Thank you again for the input. I still hope this thread is helpful to those trying to get their beloved vehicle properly serviced. A mechanic should be able to stand by what they say and prove it from an engineering point of view; not a part changer....
I got opinions, but they don't hold water if I can't substantiate it scientifically (so to speak).
Be well all!
#21
I wouldn't bother with a K&N filter. If you're really concerned about air flow, get a foam filter that doesn't need to be oiled and call it a day. The performance gain is not worth the cost of the filter + cleaner + oil kit, not to mention the amount of MAFs that I have seen that were ruined because of the oil.
It depends on what you're looking for. Performance, longevity, filtration? Any part that has the ability to ruin other parts on my car for none-to-minimal gains is an inferior product. It's not scientific, it's common sense.
Performance: You won't find it in an air filer. Look elsewhere for power.
Longevity: K&Ns do last for a long time, but they need to be cleaned and oiled. It comes to personal preference on that one (i.e. how much is your time worth to you)
Filtration: Any 'premium' air filter will easily meet or beat K&N in filtration.
Personally, I run NAPA Gold Filters and I've never had a MAF let go due to them. The membrane is dense enough to where I can clean it once or twice without it degrading.
Who states that the K&N air filter is inferior to paper ones?
Performance: You won't find it in an air filer. Look elsewhere for power.
Longevity: K&Ns do last for a long time, but they need to be cleaned and oiled. It comes to personal preference on that one (i.e. how much is your time worth to you)
Filtration: Any 'premium' air filter will easily meet or beat K&N in filtration.
Personally, I run NAPA Gold Filters and I've never had a MAF let go due to them. The membrane is dense enough to where I can clean it once or twice without it degrading.
#22
Red Card Crew
iTrader: (24)
The foam is the absolute worst for letting dirt though.
The dry filters are great. But they end up not cleaning out 100% and get clogged up over time and losing their flow.
The best filter is the oem style paper and changing it out frequently. Good flow and great filtration. Just gets clogged up and needs changing.
The dry filters are great. But they end up not cleaning out 100% and get clogged up over time and losing their flow.
The best filter is the oem style paper and changing it out frequently. Good flow and great filtration. Just gets clogged up and needs changing.
#23
#24
I actually talked with a few engineers (one of them is a materials science engineer) because I found this particularly interesting. NONE of the engineers I spoke with believe the filters would or could cause a problem. The premise of every one of the engineers i spoke with, was the same. oil is not a corrosive. further, it should be a simple matter of cleaning the sensor.
Yeah, i'm an engineer too. A filter shouldn't cause an issue. However, i still take aftermarket parts off before I go to the dealer if there is a remote chance the affected part is even remotely related to the aftermarket part.
I had a fight with a dealership over what ended up being a seized REAR caliper because I had changed my own FRONT brakes myself...with nissan parts. It's bad enough when they refuse to do work due to replacing OEM parts, let alone aftermarket. They also apparently believe nobody but their own techs are qualified to fix their cars...but that's another rant for another day. I'm so glad my car is not under warranty anymore so i don't have to deal with that BS.
Dealers...they aren't here to be our buddies or help us out...there are here to make money.
Last edited by Mustang5L5; 09-20-2011 at 03:35 PM.
#25
http://www.bobistheoilguy.com/airfilter/airtest1.htm
there are other independent tests that came to the same conclusion.
K&N filters allow more air in, but the cost is letting MUCH more dirt in than typical OEM filters...
have you noticed that K&N NEVER talks about their filtration rates... only their air flow rates..
#29
I'm actually a filtration engineer. But you gus are right, your trade off for high flow, is a loss of some retention. As filters clog, they do filter better, but you lose flow.
Every day I get tasked with trying to make filters flow a bazillion liters of air per hour, and filter everything down to 0.001 micron. It's hard.
Every day I get tasked with trying to make filters flow a bazillion liters of air per hour, and filter everything down to 0.001 micron. It's hard.