Taken from my thread on STOC, thought people could benefit on here too.

I'm due to be fitting my Wolf CAIS in the next couple of weeks so after I washed the car I figured I might just give it a freshen up, clean the hoses and the casing. As I was cleaning the casing I had a look inside the neck of the filter and thought "hmm looks clean". I then thought can I be bothered taking the whole thing apart and cleaning and re-oiling it? After looking at that it was a handful of hex screws I thought "what the heck might as well".

Filter comes out, bone dry like a piece of cardboard. If it was ever oiled in its life, it hadn't been for quite some time. The filter itself was full of dead bugs, leaves, small stones, bits of dust, pretty damn dirty! So at this point I'm glad I've taken it out. Now I have a K&N recharge kit, but I've always thought their degreaser was a bit limp wristed as it doesn't smell potent and is similar to some stuff I bought for cleaning my nitro RC cars which was the worst degreaser I ever bought since it was so shit it could barely clean a dirty dinner plate never mind grease, oil and other crud. So I went for one of my stronger engine degreasers:

http://www.perfectly...eaner-890-p.asp

This is some of the best stuff I have come across, shifts even the most stubborn and hard stained surfaces with a bit of work. Now I am weary that using something powerful may harm the gauze and element of the filter so I just sprayed it on and left it for about 5-10 seconds and immediately rinsed off...the amount of black crap that came off the filter was unbelievable!!! I could not believe this filter had been previously filtering air for an engine. If I was to be breathing through that I would probably be dead by now...

So this post is basically to advise people to CLEAN AND OIL YOUR FILTERS! You can never service a car too often is my motto and it just goes to show how much shit your filters will be accumulating. The casing of the filter was just as bad. So my advice would be use a strong degreaser, clean and oil your filter regularly and keep an eye on how many miles you go!

Happy servicing!

 

And if you are fitting a Mountune cais to a Fiesta ST make sure it isn't touching the throttle body as it rubs through the wires.

 

Be very careful what type of degreaser you use on cotton or foam filters, they can shring the cotton or destroy the foam very easily. That's why the K&N Recharger degreaser is so mild.