K & N Box filter, causing engine wear?

Post by **rspi** » 24 May 2017, 09:35

I installed a K&N box filter about 150,000 miles ago. I also am on 10,000 mile oil change intervals. I do a compression test every time I replace my spark plugs, I figure since they are out, why not.

K&N filters are rated for 1,000,000 miles. I realize not to many people drive that far so it's hard to gauge wear. I get comments (on YouTube) time after time about how my engine is going to wear out using the filter because the size of dirt it catches is not small enough. I have not bought into it so far but I wanted to know if anyone here has run a K&N filter for a long time?

When I checked my compression at 205,000 my numbers were something like 175 / 178 / 176 / 179 / 174. I now have a different compression gauge and my last readings were 152 / 154 / 158 / 153 / 152 at about 310,000. I'm going to check again today and see what my numbers are.

Post by **theWIFES_S70** » 24 May 2017, 09:48

How many times did you clean your K&N filter in those 150k miles?

Post by **mecheng** » 24 May 2017, 10:08

Just remember, a clean filter lets more particles through; therefore, let the filter get dirty.

Post by **jimmy57** » 24 May 2017, 10:24

LOL. gauze filters.

"Your car is so dirty."
"No, that is the UV protection film I leave on the paint and wheels to shield them from UV degradation"

It is true that paper media OE filters also have smaller particle capture size as they get dirtier.

I see great differences in compression readings if the equipment is different and if the test method is not EXACTLY controlled.
Is throttle held partly open?
Is engine at the same temp?
Battery condition the same for close cranking speed?
Altitude the same?
Is the engine spun until gauge no longer climbs so the hose yield and any restriction in fittings or gauge is not an issue?
Is the gauge reading zero with no pressure?

Leakdown testing has a lot of the variables reduced but the percentage leak will differ on the same engine/same cylinder with different brand testers used.

Post by **rspi** » 24 May 2017, 15:46

Went to do my compression test today and the gauge failed on the first cylinder. lol Used the one from the shop and got 152 / 160 / 140 (wet 160) / 155 / 162.

Post by **rspi** » 24 May 2017, 15:49

jimmy57 wrote: ↑24 May 2017, 10:24 LOL. gauze filters.

"Your car is so dirty."
"No, that is the UV protection film I leave on the paint and wheels to shield them from UV degradation"

It is true that paper media OE filters also have smaller particle capture size as they get dirtier.

I see great differences in compression readings if the equipment is different and if the test method is not EXACTLY controlled.
Is throttle held partly open?
Is engine at the same temp?
Battery condition the same for close cranking speed?
Altitude the same?
Is the engine spun until gauge no longer climbs so the hose yield and any restriction in fittings or gauge is not an issue?
Is the gauge reading zero with no pressure?

Leakdown testing has a lot of the variables reduced but the percentage leak will differ on the same engine/same cylinder with different brand testers used.

Lots of variables. Didn't realize altitude would effect it. When I get a new gauge, I'll have to run a test elsewhere, Here we are at 5,400 feet.

Post by **misha** » 24 May 2017, 15:50

mecheng wrote: ↑24 May 2017, 10:08 Just remember, a clean filter lets more particles through; therefore, let the filter get dirty.

Post by **wizechatmgr** » 24 May 2017, 16:08

14.6 PSI atmospheric pressure at "sea Level" compared to ~12 PSI pressure at 5.5k ft. When you account for the fact you have ~82% of the atmospheric pressure now involved those numbers at that altitude are reasonable. This assumes my math and logic is in the ballpark of being correct - it may not be.

I'd only retest it using the exact same piece of equipment I did the first time at roughly the same location under the same conditions. Most meters/gauges, etc you and I can purchase without going broke aren't all that accurate and are almost never calibrated. And you can bet it has no form of altitude compensation...

Altitude reference: https://www.avs.org/AVS/files/c7/c7edae ... f87b9e.pdf

Post by **theWIFES_S70** » 24 May 2017, 17:44

misha wrote: ↑24 May 2017, 15:50
mecheng wrote: ↑24 May 2017, 10:08 Just remember, a clean filter lets more particles through; therefore, let the filter get dirty.

Not trying to stir up a clean air filter vs dirty air filter debate, at least not without windtunnels, norming for barometric pressure, and so on, but aren't clean air filters good for cars?

Post by **tryingbe** » 24 May 2017, 18:45

http://www.turbo-mopar.com/forums/showt ... highlight=

I clean it once a year and spray a little K&N oil on it every oil change. It's due for a cleaning but WTF. I've gone back to a paper Wix filter. It's really dusty here in Arizona. I don't think the K&N is up to keeping out the very fine particulates in the air here.