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Discussion Starter #1
The question: Anyone use a pre-filter on the stock JK 3.6L Pentastar motor? If so what parts have you used?

Our Jeep club just finished the "Heart of the West route", about 2600 miles of dirt roads through the historic Rockies and plains, Wyoming, Colorado, Utah Idaho and Nevada. The roads were extremely dusty.

Lots of dust collected on my stock paper filter. I didn't have a new spare and since the others were banging their filters on their tires I reluctantly did the same. I also noticed that fine dust was getting past the filter and dust was inside the plastic air intake walls.

Any dust getting into the engine is very bad in my opinion. I cleaned the intake and reinstalled the stock filter. Each time I took the stock filter off there was that fine dust getting past. I know not the right way to clean paper filter should be remove and replace with new but that was the only thing to do out on the trail.

Note an AEV Jeep with the snorkel also had a similar amount of dust on the stock filter so the snorkel wasn't reducing the amount of dust getting to the filter. The K&N guys had to wash their filter often but reported no dust getting past.

At this point I don't want to go K&N, I want to stay stock. But the air filter needs to be improved. I am considering a pre-filter. I successfully have an old foam pre-filter on my motorcycle and it works well with very little dust getting to my stock filter.

And why not just go with the K&N? I want to keep things stock and also the oiled filters get nasty dirty and need cleaning often. Not sure I want that nasty job all the time. But maybe!
Along the emigrant trail South Pass Wyoming
 

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Just a thought: how about a K&N for the trails that you pull out for daily or lighter driving and continue using the OEM filter. That way the cleanup is only after the arduous trails you would expect to have extra work to do after anyway. I don't know, maybe not worth the effort but I've not seen any prefilter arrangements like a bike has.
 

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Discussion Starter #3 (Edited)
OP update: Actually an alarm to all of those with stock air filter boxes on JK's... this is bad folks! The stock Jeep JK filters are failing on dusty runs.

Pic of clean side of stock engine air filter. Obviously the dirt is getting past the edge gasket of the filter housing.


Other side of the air box on the clean side


I'm thinking the fix will be a health dose of filter grease on the filter gasket seal and making a pre-filter.


As to the K&M type.. for years I have heard they are more pores and not as good as the stock paper. In this case the filter is failing along the seal. I'll be working on the seal and report back. Plus try to configure a pre-filter.

Again this is bad, bad, bad:(
 

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...Again this is bad, bad, bad:(
Yes it is.

There was an Allegro Bus (diesel pusher coach) parked next to me at a Freightliner dealer in Phoenix (I was getting our chassis serviced.) I was curious about why it was there and asked the service manager about it. The guy just bought it and the story goes that Camping World installed the air filter backwards during routine maintenance and the result was the engine was "dusted." The entire engine had to be rebuilt - new turbo, and I assume new cylinder sleeves (I think the Cummins ISL has sleeves), etc. A $30K rebuild.

(I had to have the head pulled on my ISL and have a valve job done - only $10K :crying:)
 

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Yes it is.

There was an Allegro Bus (diesel pusher coach) parked next to me at a Freightliner dealer in Phoenix (I was getting our chassis serviced.) I was curious about why it was there and asked the service manager about it. The guy just bought it and the story goes that Camping World installed the air filter backwards during routine maintenance and the result was the engine was "dusted." The entire engine had to be rebuilt - new turbo, and I assume new cylinder sleeves (I think the Cummins ISL has sleeves), etc. A $30K rebuild.

(I had to have the head pulled on my ISL and have a valve job done - only $10K :crying:)
When I had my toterhome I quickly learned to stay away from Camping World's service department. My opinion is they are very under qualified and perform sub standard shoddy work.
 

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I don't recommend the K&N as a solution unless the design has changed significantly. The average particle size that gets through a K&N is much bigger than a paper filter. Besides, the issue here isn't what goes through the filter, it's what gets around the filter.
 

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Discussion Starter #7
OP here:

A fellow Jeep club member recommended I only use the Mopar OEM filter from the dealer. The failed filter was a Fram. I'll compare the outer seals and give an update. But from now on will use rim grease.

I have research the net looking for a pre-filter for a Jeep JK and have found none. I know what to do as my big adventure bike has a pre-filter and I also use filter skins.

Since I have an AEV hood, right at the intake, is a screened opening designed for engine cooling. But that may be sucking in dust as the intake is up against it. I could just put an oiled filter skin across the air intake. Might reduce the air flow a bit but it would sure help keep out dust. They are cheap and are cleanable. I imagine that I could change these out daily on a dusty run.

Here is a shot of the vent and wonder if that is a dust concentrator?

Utah east of Provo, the Wasatch Range.
 

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OP here:

A fellow Jeep club member recommended I only use the Mopar OEM filter from the dealer. The failed filter was a Fram. I'll compare the outer seals and give an update. But from now on will use rim grease.

I have research the net looking for a pre-filter for a Jeep JK and have found none. I know what to do as my big adventure bike has a pre-filter and I also use filter skins.

Since I have an AEV hood, right at the intake, is a screened opening designed for engine cooling. But that may be sucking in dust as the intake is up against it. I could just put an oiled filter skin across the air intake. Might reduce the air flow a bit but it would sure help keep out dust. They are cheap and are cleanable. I imagine that I could change these out daily on a dusty run.

Here is a shot of the vent and wonder if that is a dust concentrator?

Utah east of Provo, the Wasatch Range.
i have the same hood on the last 2 JK`s ...
have not come up with a solution - other then having an extra paper filter
i blow out the trail filter with air from garage compressor and have used portable air on dusty trail when stopping for lunch
:wink2:
 

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I was going to suggest a sealant around the rim of the filter.
I didn't even realize that they had something specifically for that purpose.
Since I took the picture of what I use on my Cummins, I figured I'd post it. :)

Anyway, AEM makes synthetic element dry type filters for the JK. They are a subsidiary of K&N, so not sure if that means anything.
They do have very good independent test results for filtration. One step in the cleaning process is tapping the element to dislodge loose dust/dirt. Maybe that would be sufficient for periodic cleaning??

They show using a cleaner as part of the process. (Note: they used to recommend Simple Green)
Again, not sure if any of this is necessary for the periodic cleanings.
They also show the use of compressed air if needed.

https://www.aemintakes.com/search/product.aspx?prod=28-20364

BTW, that is a very nice looking Jeep. Looks like you're having fun.
 

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Discussion Starter #10
I was going to suggest a sealant around the rim of the filter.
I didn't even realize that they had something specifically for that purpose.
Since I took the picture of what I use on my Cummins, I figured I'd post it. :)

Anyway, AEM makes synthetic element dry type filters for the JK. They are a subsidiary of K&N, so not sure if that means anything.
They do have very good independent test results for filtration. One step in the cleaning process is tapping the element to dislodge loose dust/dirt. Maybe that would be sufficient for periodic cleaning??

They show using a cleaner as part of the process. (Note: they used to recommend Simple Green)
Again, not sure if any of this is necessary for the periodic cleanings.
They also show the use of compressed air if needed.

https://www.aemintakes.com/search/product.aspx?prod=28-20364

BTW, that is a very nice looking Jeep. Looks like you're having fun.
Thanks FLLJ for the tip on the AEM filter.

I checked it out and the price, looks reasonable and the reviews encouraging. I googled the chemicals in the cleaner and think they are standard cleaning agents and maybe a little harsh. Some reported that the AEM recommended cleaner bleached the red out of the fabric! But it didn't effect the effectiveness. Since the claim is the AEM filter removes 99% of harmful contaminates I think the pre filter of filter skins should be run as well to get the pesky 1%:serious:

I don't want to have to carry a specific cleaner. I think dish soap and water will clean the filter and not damage the material, unless I hear differently. I do have CO2 and can give the filter a blast on the trail as well.

So thinking the reusable AEM dry filter with a filter skin over the air intake on dusty runs. Maybe keep on the filter skin if no noticeable power loss or gas milage drop. I will be watching the filter situation, I never want to see dust in the intake again. I will experiment with the Mopar filter as well.

Dust off my filter after one wack on the wheel.
 

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Just my experience,
My rig came with a K&N intake. I threw away the K&N filter and got an AMSOIL cone filter (no oil) with an outer cover. The result after 6 months in Baja and their terrible silt beds I took the filter off and washed it. Huge amount of fine silt came out. The outer is not oiled and it had little silt. The outer is not a filter, but is there to catch large debris and keep big stuff off the regular filter. It is not restrictive at all. Probably a waste of effort to use that kind of outer? Anyway that setup is not perfect as I had some dust on the inner intake pipe.
The Amsoil uses a Nano fabric like the Donaldson uses, so I thought it might be better than the K&N.
A long time ago I fell for the K&N hype and I was severely disappointed by the heavy silt in the intake. Then when it came time to clean and re-oil there is no way to quantify how much oil to use. To little and it passes dirt To much make a mess and restricts air flow.
I even tried an oil saturated foam filter. Same comments about the K&N apply, except a bigger mess and I hated the cleaning oiling process.
For now I will stick with the AMSOIL one. Its cost was similar to most aftermarket filters.
Comparing the AMSOIL it had less dust in the intake than the others, regardless on my oiling technique.
BTW, my son's Baja racer uses a conventional, but large paper filter with a thick foam over wrap. The over wrap has to be replaced or cleaned during his various races. It seems to collect the silt just as good as the paper filter so it clogs pretty fast. It is not oiled.
PaulW
 

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I just checked my filter, dirty as hell but nothing went past it. Mopar filter.
I think your easiest and cheapest solution would be to just get rid of all you friends. That way you'll never have to follow anyone, clean air all the time.
PWMAC, I have ran into this kind of filter, mostly on diesel trucks, they have a foam bonded to the paper element. The ones I have seen have a sticky substance on them from the factory. They are desirable for trucks that get used in mines. Coal dust can destroy a engine quickly. Does your son go through a lot when racing?
 

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Discussion Starter #14 (Edited)
OP update: Have installed the Mopar filter and used rim grease. Also have a filter skin on the intake and will report later the effectiveness. Filter skin is essentially cheese cloth.

Talked to a pro mechanic about the filter fail. He suggested that when the filter got clogged with dust and I got onto the highway the engine pulled the filter hard enough to suck in the middle and bend it. That allowed air flow along the rim and into the clean side of the filter.

I was able to examine several Jeep JK air filters and this is my unofficial view based on "eye balling" while getting briefed by an experienced mechanic about their construction and integraty.

Microguard: The failed filter, It was OReily's "go to" filter a Microguard made in Korea. Actually this filter is made well with thick tight filter material and a fused rim seal similar to the Mopar. I'll admit the failure is all mine. I should have replace the filter at the end of the trail and not run it on the highway.

Fram: This filter is indeed subpar and cheaply built with thinner filter material. The Fram rim gasket is thin and not even glued to the filter and can be pulled off easily. Made in China.

Wix: The Wix looks better than the Mopar. It is built as good as the Mopar but what makes it better is it has a reenforced structure to keep the filter from caving in when loaded with dirt.

Mopar: The Mopar air filter has heavy fabric and a thick gasket glued to the filter and appears strong and stiff. But doesn't have the reinforced part like the Wix.

Pics failed to load to my gallery for some reason:(
 

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There's some YouTube videos of guys cutting various oil filters in half and Wix brand was hands down the best of the bunch. I think that guy mentioned Wix makes Napa Gold filters. Fram oil filters were one of the worst he evaluated. I'm guessing Wix makes quality air filters based on their oil filter construction.
 
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