Hmmm thats an interesting point...however at what point do you get to that allowing a "little" dirt/dust into the engine with all that extra air is it worth it or not worth it.

I mean...sure the paper filter probably traps like 90% or more of the crap...maybe a K&N doesn't but the airflow is a huge difference...what is the effect on your engine of dirt/dust particles? It probably would be tough to figure that out...I'm going on 23000 miles with my FIPK and dont appear to have any troubles...however I'm cleaning it this week actually so I might take off every part up to the TB to see if its dirty and whatnot...

Also thats why I save all my stock parts...just in case!

 

Well debris in the oil causes friction, which is what oil tries to reduce. At that pressure I think it would scratch the surfaces all to hell. I imagine a lot of the dust would end up in the oil pan...
I'm no mechanic but dirt in the engine seems like a no brainer to me...bad

 

The reason why no one has made the intake for an '04 is because ford integrated the MAF into the airbox. I'm assuming that there are some companies trying to make one but I have yet to find any. So the '01-'03 will not work on the '04's. Its annoying because I want to get an intake for mine but I have to wait till some one decides to get the S*** together and make one. Oh well right....

 

K & N introduced their 2004 and newer Ford 4.0 liter FIPK last week - I already have mine on order.....

 

just make sure u don't get lazy on it....turst me ull notice a milage difference if u do

 

Of course a K&N doesn't filter as well, but that's what the oil is supposed to do. It catches the smaller particles the K&N Cotton(?) filaments will let through. But the reasoning is that smaller particles don't hurt as much as larger particles, that or you keep it oiled well enough to keep that filtration present (but not too much oil, or you can have MAF problems as stated above).

 

I've heard of people taking everything thing off, and running their finger around the throttle body and it coming out black, they were using a K&N