doubledaddy

Hello from PA fellow enthusiasts!! I wanted to know if K&N Filters pose any inherent dangers to my 2006 550I engine. I put a new K&N Filter in after I let the oil drain off in the sun for a few days. There is still a small amount of oil left on the filter, but not enough to damage the air regulator. However, when in park my car seems to idle slightly sparaticly. Has this happened to anyone else? Should I have listened to the dealer when they recommended not to use K&N Filters?

ktlocklear

I've been using one in my 550 for almost a year now...no problems. Have you cleaned the maf? I do spray mine off with CRC maf cleaner every 5k miles when I change the engine oil.

doubledaddy

I haven't really dabbled under the hood yet. My bumper to bumper 4yr/50k just lapsed so im just jumping in now so i dont have to pay those blood sucking bastards at the dealer !! My BMW jargin is a little out-dated so could yo elaborate a little on what a MAF/CRC is. im GOOD under the hood, just need to get up to speed that's all.

doubledaddy

I haven't really dabbled under the hood yet. My bumper to bumper 4yr/50k just lapsed so im just jumping in now so i dont have to pay those blood sucking bastards at the dealer !! My BMW jargin is a little out-dated so could yo elaborate a little on what a MAF/CRC is. im GOOD under the hood, just need to get up to speed that's all.

ktlocklear

Here is a diy on how to clean the maf....it's not a 550, but same steps. https://5series.net/forums/topic/980...&#entry1164901

just follow the air intake pipe from the air box towards the engine. The maf is the small black box on the air intake pipe that has the wire harness.
Simple to remove. Pop the clam shell cover which is held on by 2 small tabs, unclip the harness plug, then unbolt the 2 torx screws that hold the maf to the air pipe. Then just slide out the maf from the air pipe......hose down with crc maf cleaner, let dry, and re-install in the reverse order. Should take no longer than 15 minutes

response_surface

you may have put too much oil on it. i just had the same problem on one of my bikes...i cleaned and oiled the k&n with their kit, the bike ran so badly after.... so i blew off most of the oil with compressed air, although k&n says not to. bike runs perfectly now.

all that being said, i wouldn't put a k&n on my car, they allow much larger particles to pass through than a stock filter would.

doubledaddy

Thnaks for the advice. I actually never put any oil on at all. It came all "lubed up". After speaking to a Dinan Specialist at the dealer, he recommended that i just leave it out in the sun for a few days, which worked suprisingly well. I too, am concerned weather the filter will allow smaller particles to get through versus the stock filter.

doubledaddy

This is good stuff man, I'm going to give it a whirl. Shit, theres almost 50k mi. on my car now so it couldn't hurt right!!

As of late, I have been contemplating whether or not to get a decent horse power upgrade. Just wanted to know what your thoughts were on the Dinan products. Was seriously considering a stage three software upgrade + Dinan intake air filter (has two pipes for air inlet)system + the larger throttle body. It's not massive, but should raise the bhp to about 385.

medik13

I have a K&N. I didn't put it in the sun or any of the methods described here. I just put it in the car and the car runs perfect. Don't think so much about it. Put it in and enjoy the car. The car will be fine!

response_surface

the k&n will for sure let larger particles through. you can check their website, i think they'll pass particles as large as 10-25 microns, stock filter will likely limit size to 5 microns. bottom line is that if the filter has less flow resistance then it must have more open area. just plain old fluid mechanics at work here. i use them on my bikes b/c a new engine for a bike doesn't cost 10-20k like it would for my 545i. plus the hp gain in the car due to the filter are so small its not even worth the risk.