L5P: K&N Air Filter Replacement - Diesel Place : Chevrolet and GMC Diesel Truck Forums
Home Forum Market Place Garage Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Diesel Engines > Duramax Sixth Generation: 2017-2019 (L5P)
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Advertise

Duramax Sixth Generation: 2017-2019 (L5P) Discuss the sixth generation of the 6.6L Duramax diesel engine & associated components. Engine related discussion ONLY.

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Like Tree9Likes
  • 2 Post By OkDually
  • 3 Post By sfcjones
  • 1 Post By STLCHEVYHD
  • 1 Post By blkdmax05
  • 2 Post By Ted White

LinkBack Thread Tools
Old 09-21-2019, 11:04 AM   #1 (permalink)
Gear Grinder
Jcalderwood's Avatar
Join Date: Sep 2019
Location: Bakersfield CA
Posts: 2
iTrader Score: 0 reviews

K&N Air Filter Replacement

I'm new to the diesel world, so please forgive my incompetence. I purchased a 2019 GMC 2500HD SLT and was going to replace the filter with a KN. Are there any pros or cons to be aware of? Thanks for any responses.

2019 GMC 2500HD SLT L5P

Last edited by OkDually; 09-21-2019 at 11:35 AM. Reason: sig
Reply With Quote Quick reply to this message
Sponsored Links
Old 09-21-2019, 11:34 AM   #2 (permalink)
OkDually's Avatar
Join Date: Jul 2013
Location: N.E. Oklahoma
Posts: 14,483
iTrader Score: 0 reviews

DieselPlace.com Lifetime Premium Member

Welcome to DieselPlace

I would stick with the stock paper filter.
K & N filters are ok with gas engines but a diesel engine uses way more air and the cotton fiber material, no matter how much you clean it, will still retain dirt particles within the fibers.
Over time you will get an air flow restriction.
If you ever upgrade to a cold air intake, always go to a paper filter..

1996 K3500 6.5L,( "F" Eng #141 cast block) 5 speed manual, crewcab, dually longbed: 208,000mi.
Diamond Eye 4" Turbo Back Exhaust w/2.5" Flo-Pro Crossover
AirDog II DF165 w/ tank sock delete - XDP
TD-Max boost controller - Kennedy Diesel
OPS extension hose - Leroy Diesel
Glow Plug Harness- PT Wiring Solutions
Glowshift Maxtow EGT,Boost, Fuel gauges
Boost & Fuel Pressure Bolts - Leroy Diesel
2/0 Battery Cable Upgrade - PT Wiring Solutions
PMD w/#9 resistor and Re-Location Kit, mounted to bumper - Leroy Diesel
GM-5 Turbocharger
4.10 gear ratio
OptiLube Winter Formula

Proud member #1039 of The 3500 Dually Club

Offline   Reply With Quote Quick reply to this message
Old 09-21-2019, 01:09 PM   #3 (permalink)
Gear Grinder
Jcalderwood's Avatar
Join Date: Sep 2019
Location: Bakersfield CA
Posts: 2
iTrader Score: 0 reviews

Thank you sir. I greatly appreciate you
2019 GMC 2500HD SLT L5P
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Old 09-23-2019, 12:11 AM   #4 (permalink)
Diesel Boss
Join Date: Jul 2004
Location: Portland, OR
Posts: 1,465
iTrader Score: 0 reviews

a previous test years ago showed that the factory filter was much better for filtration than the K&N and virtually all aftermarket filters. Down side was a very slight increase in pressure drop.

IMHO stick with the OEM.
2015.5 Sierra Denali CC/SB/4x4 Stone Blue Metallic/Jet Black Interior
pinstriping by Bob Spencer AKA "spirit", undercover FLEX tonneau cover, color matched bug shield and vent visors, raintracker rain sensing wipers, X-treme coating bedliner, gm trailering camera system, coolant filter, Bilsteins, remote tailgate lock

04.5 LLY CC/SB/4x4 Allison Dark Green Metallic/Dark Charcoal Grey Interior
Webasto Hollandia Sunroof, Carbon Fiber Interior Trim, color matched bug shield & vent visors X-treme coating bedliner, Access roll top cover, Westin Step Bars, Lubrication Specialists Aux fuel filter, coolant filter, CAI, Michelin LTX tires, Manual High Idle Mod, Bilsteins, prodigy brake controller, raintracker rain sensing wiper controller, Remote autolocking tailgate, Reese Titan Class V hitch, Allison badges, Pinstriping by Bob Spencer, 4x4 decals removed, color matched door handles, 4 headlight mod, Homelink console.

97 Mercedes SL500, red with tan interior 97 Mercedes E420 sedan, royal indigo with grey interior 2001 KTM400EXC, 2011 Outback 295RE travel trailer
Offline   Reply With Quote Quick reply to this message
Old 09-23-2019, 06:05 AM   #5 (permalink)
Diesel Legend
sfcjones's Avatar
Join Date: Mar 2007
Location: Back in South GA...
Posts: 16,147
iTrader Score: 1 reviews

Georgia Diesel Owners Club Member

Armed Forces Club Member

I wouldn't waste my money on any K&N Filter junk...Nothing but hype, no gains to be had. Waste of money.
2009 Chevy CC 2500HD LTZ LMM Z71 283k miles
2004 GMC SLT LB7 CC 455k Miles (Retired)(Sold)
2007 Chevy Tahoe with Ranch Hand 240k Miles
2010 Chevy Suburban LTZ 75th Diamond Edition, 106k Miles
Member #67 A(ACLU) Agent Sgt. Slaughter
DP Jug Holder #3
US Army Veteran 25 Years of Service
You haven’t lived ‘til you’ve almost died. For those who have fought for it, life has a flavor the protected will never know.(MACV-SOG)
'A man will reveal his character through his actions, not his skin color.'
Romans 10:13 For Whosoever shall call upon the name of the Lord shall be Saved.
NRA Patriot Life Benefactor Member
Offline   Reply With Quote Quick reply to this message
Old 09-24-2019, 04:34 PM   #6 (permalink)
Diesel Boss
Join Date: Jul 2006
Location: St. Louis, MO
Posts: 1,128
iTrader Score: 0 reviews

Midwest Smokers Member

I saw a YouTube video of a guy that did some dyno testing with a tuner (forgot which) and then adding a K&N intake. He actually lost power when he added the K&N setup over the stock box.

2018 Chevy LTZ L5P 4x4 CCSB
01 Chevy 2500HD ccsb 4x4, black, 241k+
4" Magnaflow exhaust, Dick Cepek Extreme Country 285-75-16, Raceline Raptor 16x8's
MA450 trans; WCFab intake & horn; Stealth 64 turbo w/ WCFab down pipe; driver's side manifold and up pipes; MA T-Case Upgrade
Duramaxtuner's DSP 5 EFI Live Stock motor, built trans, & TCM tune setup, FASS 150, Exergy Sportsman pump
Autometer Ultra-Lite Pyro/Boost gauges
All 8 injectors replaced by me at 160k and 218k using Bosch remans from LDS, Cognito UCA's w/ Moog Ball Joints, Moog Idler/Pitman w/PISKS, Kryptonite tie-rods, 1" rear blocks, Sulastic shackles

Offline   Reply With Quote Quick reply to this message
Old 09-24-2019, 07:42 PM   #7 (permalink)
Diesel Pro
Oregonnovaguy's Avatar
Join Date: Sep 2007
Location: Southern Oregon
Posts: 2,042
iTrader Score: 0 reviews

Save your money for better things. I had a K&N on my '03 gasser; never again. Now, having said this, and echoing all the above comments, you will soon read from at least one self-appointed "expert" that he has had a K&N on his Duramax for a million miles, and he gets better mileage, and more horsepower, and the test results are out-dated, and we all don't know what we are talking about, blah, blah, blah. It's your money, you get to decide if it's worth it or not. Welcome to the forum!
"Tolerance becomes a crime when applied to evil" Thomas Mann
“If you can live amid injustice without anger, you are immoral as well as unjust.” -St. Thomas Aquinas
"When any nation mistrusts its citizens with guns, it is sending a clear message. It no longer trusts its citizens because such a government has evil plans." - George Washington -

2007.5 Silverado LTZ / Z-71, 4x4, Crew Cab SB, Silver Birch/ Ebony Leather, , 150k + miles, , etc. Gearbox Z, Air Lifts
Montana High Country 310RE
My Other other Car: 70 Nova SS 350, 4 speed, posi, Fathom Blue, frame-off resto, original owner!
Previous Trucks: '03 Silverado CC gasser 4x4, '99 Sierra Ext. Cab 4x4, '77 Dodge Power Wagon 4x4, '76 Datsun 620.

Read the DISCLAIMER in my garage.

Last edited by Oregonnovaguy; 09-24-2019 at 07:48 PM.
Offline   Reply With Quote Quick reply to this message
Old 10-01-2019, 11:08 AM   #8 (permalink)
Charlie D.
Diesel Student
Join Date: Aug 2006
Posts: 48
iTrader Score: 0 reviews

Be aware of possible warranty issue with the K&N? I'm a believer to never do mods to a vehicle under warranty.
2018 Silverado 2500 LT 6.6 Z71 L5P
Offline   Reply With Quote Quick reply to this message
Old 10-01-2019, 06:16 PM   #9 (permalink)
blkdmax05's Avatar
Join Date: May 2010
Location: Kent Co. Delaware
Posts: 11,942
iTrader Score: 2 reviews

DelMarVa Diesel Club Member

DieselPlace.com Lifetime Premium Member

Here’s the results of an air filter study that was done years ago. Obviously the L5P wasn’t tested, but it gives you some hard numbers.

>2005 Chevrolet 2500HD CC SB 4X4 Duramax LLY/Allison<
MBRP Downpipe + 4” exhaust w/6” tip, EGR Deleted, PCV Rerouted, Resonator Blocked, AFE MP, Edge CTS Insight, Banks Intake w/Scoop, Bilstein 5100's, 2006+ Tow Mirrors, Line-X, Dually Rear Light Bar, General AT2 tires on 17” Ultra Drifter Rims, Superglide 16k Fifth Wheel Hitch, Tekonsha P3 Brake Control

Offline   Reply With Quote Quick reply to this message
Old 11-01-2019, 12:56 AM   #10 (permalink)
Ted White
Diesel Champ
Ted White's Avatar
Join Date: Jun 2007
Posts: 1,817
iTrader Score: 0 reviews

One big problem that can occur with K&N filters on our trucks is oil contamination of sensors in the air intake. Just as everyone else says, stay away from it. Just follow the recommended replacement recommendations in the manual.

2019 GMC Sierra 3500 HD SLT SRW
Offline   Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 06:12 PM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide