KJamesJR

Put one of these in the jeep last night. Returned it this morning. Easy to see were people think these give a performance boost after running on a dirty filter. Put in a Fram, felt the same over the K&N. Thought I'd share. Maybe something is wrong with my XJ, but no placebo effect here. Tested both filters back to back.

Also I need help with my drive belt tensioner. I turn the really long bolt on the PS bracket, both ways, it doesn't seem to loosen or tighten. One of my pulleys are chirping.

Radi

Did you loosen the bolt holding the idler pulley (right in the center) before turning the adjuster?

1976Mustang

I hate FRAM since everything they make is Paper, and i almost ruined the engine in my dad's pickup when the FRAM oil filter failed on it. Also K&N filters are nice since you just pull them out, clean them with the kit and throw them back in, saves money and a trip to the store.

salad

FRAM oil filters are generally junk but their air filters are fine lol. The Tough Guard one is a pretty solid unit (yellow paper w/ black trim, vs white paper w/ orange trim)

I take it you replaced the stock panel air filter with a K&N drop-in, and you're not talking about a cone filter like the so-called "CAI" kits?

I've never been a fan of the idea of more airflow in the same surface area. IMO if you want more air, get a bigger filter. When a paper filter gets packed with dust, it flows less but the filter media is intact. An oilable filter relies on being 'sticky, which is combined with larger pores. Well if the media isn't sticky anymore (from dust), you still have large pores and crap will get in

But very interesting that you didn't experience a difference between the K&N panel and just a new FRAM. I suspect that it would make a bigger difference in warmer temps with some heavy work. Lots of cold dense air already going into the engine in the winter anyway lol.

1976Mustang

I heard the larger pores wouldn't be an issue on gas and non-turbo engines since they don't suck in too much air, but would be very risky on diesels since they suck in so much air. As long as you service them regularly that is... Which reminds me, i gotta check my filter.

Haha, and those drop in CAI's are jokes. They just suck in hot air from the Radiator, at least the stock box has a little snorkel to get air from in front of the radiator. I did the cowl snorkel for the cool sound and to make room in the engine bay for future mods.

Jesse Hallum

Fram and K&N products appeal to a certain targeted segment of our popluation. I don't buy this stuff, nor do I recommend it to anyone else. I do wish I had a dollar for every unhappy customer I've run across, however.

djb383

As stated.......loosen idler pulley 1st (yellow circle), then 2nd (red circle) turn the adjusting bolt, then re-tighten the idler pulley.

The air flow restriction is not from that big 'ol paper air filter......the restriction is the small throttle body, followed by the butterfly inside the throttle body, them the intake runners, the head intake ports and finally those little "nail head" intake valves.

1976Mustang

For K&N? Honestly the only reason i actually got the K&N for mine is I couldn't find the FRAM/Microguard equivalent, and i needed the shape/size it was so it would fit right and not block the cowl off, while still allowing sufficient air into the engine.

Bustedback

Hold a fresh K&N up to a light, you will see holes that can let a lot of crap through to the engine. They look like a red shop towel that is sandwiched between some mesh. I don't trust them and they're a PITA to clean properly.

scottmphoto

I've been running K&N airfilters for years and haven't had a problem. Granted, I don't wheel in real dusty areas most of the time. Mine have always been fairly easy to clean. When I put my first K&N on my first XJ, I noticed a 3-4 mpg increase, just as I was told to expect. My main reason for getting one was to be able to clean and reuse it. They have saved me a bit of money over the years. If they didn't have a good reputation, they wouldn't still be so popular. In my own opinion, I'll never buy anything else.

Bob98Classic

The best filters I have ever used, is foam filters.

My motorbike came with a foam filter, easy to clean, and reinstall.

After 9 years, I had to replace it. The carbs looked very clean

after 9 years also, and when I finally sold the bike after 17 years, the

carbs still looked new....

KJamesJR

I must have overlooked that step in the Haynes Manual. Or it wasn't in there.

KJamesJR

Have you checked you mpg recently? I've only heard of a mpg boost BEFORE the cpu re-adjusts. I've never heard of a K&N giving higher mpg.

Also, I don't mind the Fram AIR FILTER. They're cheap and seemed to be a little better made than the STP for about a buck more.

When I was running the K&N, I was getting a rougher ride. Both idle and acceleration... Only way I can explain the sound was like metal rubbing together. I was hoping it would run better with my APN manifold, but I didn't really notice anything. Anyone else get this?

RTorrez1

I have been running a K&N cone filter on my 98 for the last 4 years and I have never had a single problem with it. The main thing is that you do have to keep it clean and oiled. Plus I do run the pre-filter on it which is just a little bag that fits over the cone filter. I live in south Texas all around me is nothing but farmland. I have never had a problem with all the dirt and dust plugging it up or sucking up dirt & dust plugging anything up.

jeepscottr1

I put a rugged ridge filter off quadtratec and I use k&n oil filters the rugged ridge is washable and the k&n oil filters actually metal not cardboard