K&N Air filter whistling

[Tomster]

Not a fan of oiled filters. Go easy on the re-oiling if you go that route @Tomster, you don’t want to mess up the sensors. I’m sure you know that...

Curious you went w the K&N after you had the issue with the first car. How did that resolve or did you sell/trade in w it still whistling??

Never knew that was the issue with the other car. It sounds more like a screech than a whistle. I traded the 16 in and didn't remove the filter. Started anew with the R and had no issues with the filter until after a 3 day track weekend. I may just go another filter route.

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[JAJ]

Back in 2012 or so I was doing my own final calibration on a supercharged coyote in my 2011 Mustang GT. I had the engine covered in sensors and logged them all along with the ECU data. And not just for a couple of dyno pulls - I logged data for hours on the race track. Gigabytes of air flow, valve timing, boost, spark, vehicle speed, throttle position, pedal position, etc.

One of the things I did, just out of curiosity was to measure the pressure drop across the air filter - the higher the pressure drop, the more it obstructs airflow. The OEM paper filter delivered a lower pressure drop than the K&N that came with the blower kit. The difference in pressure drop was less than 1%, so it wasn't enough to be felt by the driver, but the instruments picked it up. Since then, I've tuned out claims that aftermarket air filters improve performance. It's a myth.

 

[rj45]

Interesting, thanks.

 

[galaxy]

The difference in pressure drop was less than 1%, so it wasn't enough to be felt by the driver, but the instruments picked it up. Since then, I've tuned out claims that aftermarket air filters improve performance. It's a myth.

This all day long! In fact, just about every car I've been involved with, it usually gets debunked that "high flow" aftermarket filters do anything for you. The vast majority of the time, your air filter is not the choke point.

And, by all means Tom, do your own homework...but K&N is horrible at filtering. There's tons of data out there, and some of it is straight from BlackStone, about oil analysis with higher silica (e.g.sand) readings when running K&N. They'll even support reports of guys that drastically reduced silica in reports by swapping back to a stock or dry filter.

I won't swear to it on ever car, but I think the days of the oil messing with the sensors are over. That was mainly concerning the MAF which was typically mounted just aft of the filter to catch all the oil, but what has a old style MAF on it anymore?!

 

[Tomster]

I swapped out the K&N with an OEM filter and whistle is gone. I'm not going to bother with cleaning out the K&N and re-installing. Hopefully that if this happens to someone else, then this info will help.

 

[Shift]

I sometimes get a loud whistle/high pitched rattling at around 5.5k RPMS. I will keep an eye on the FP Airaid filter next time, thanks.

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