Never, never, never try and fit an air filter!!

[powers1]

I posted this way back in April last year,should make you feel better ,Dave!
http://www.automotiveforums.com/t402...ir_filter.html

[rmcox1991]

I installed a brand new K&N filter for a 2001 4.4i last summer. After a couple of months, I noticed surging when coming to a stop and also the engine revving up on start-up. One day the CEL came on. Needless to say, I didn't want to take it in to the dealership and get bled dry so I bought a ODBII code reader. I was getting a Camshaft Position Sensor error so I replaced it. After a couple of days, the light came back on now it was showing an error for the fuel/air mixture in the left and right banks. I was hoping that it wasn't my Mass Airflow Sensor but after some research on here that's what I concluded that problem had to be. So after $300 on the part and 10 minutes labor, she's running fine. I'm getting better gas mileage now with an OEM filter than I did with the K&N. I got 22 MPG averaging 80 MPH on a 250 trip from Tulsa to Dallas! All highway driving of course. Long story short, keep away from the K&N filters, the oil will gunk up the filament on the MAF sensor and you'll be out $300!

[dave_p]

Thanks guys for your posts. I have just got back from the dealers - hell, I even left the tunit performance box on - did they care? No, not at all. They are brilliant.

The chief technician fitted an OEM air filter in 40 minutes - which he tells me is quick. They charged me 20 minutes labour. I also got them to replace the pollen filter and a few plastic retaining clips (which I lost somewhere in the engine bay!!!!).

The technician told me that the K&N filter could give lots of problems, none of which would be covered under warranty - since the OEM filter had been removed.

A hard lesson, but one that I learnt earlier rather than later. I wont be messing around in the engine bay again.

Regards,

Dave

[powers1]

Originally Posted by rmcox1991

I installed a brand new K&N filter for a 2001 4.4i last summer. After a couple of months, I noticed surging when coming to a stop and also the engine revving up on start-up. One day the CEL came on. Needless to say, I didn't want to take it in to the dealership and get bled dry so I bought a ODBII code reader. I was getting a Camshaft Position Sensor error so I replaced it. After a couple of days, the light came back on now it was showing an error for the fuel/air mixture in the left and right banks. I was hoping that it wasn't my Mass Airflow Sensor but after some research on here that's what I concluded that problem had to be. So after $300 on the part and 10 minutes labor, she's running fine. I'm getting better gas mileage now with an OEM filter than I did with the K&N. I got 22 MPG averaging 80 MPH on a 250 trip from Tulsa to Dallas! All highway driving of course. Long story short, keep away from the K&N filters, the oil will gunk up the filament on the MAF sensor and you'll be out $300!

I am sure someone already said that here!

[dave_p]

Originally Posted by powers1

I am sure someone already said that here!

Wish I had read your post before I purchased the K&N. It's amazing how the K&N website leads you into a false sense of security.

From now on it's OEM, OEM, OEM.....

[omodos]

No idea how concise this is but found it on another site, a few pics and this would have been perfect, I am too worried to take it to the dealer or a mechanic as without sticking around peeping over their shoulders I won’t be able to verify they change it and do it properly, if I ask for the old filter they will get upset at my lack of faith I have in them…hmmmmmm anyone documented this with pics yet anywhere


Completed this at the first attempt tonight. Do it better than the dealer, - who can't be bothered doing it properly, as you'll never know - or so they think.

It's pretty easy, but very time consuming, for what should be a 10 minute swap.

NTS = NO TOOL REQUIRED

before you start, you WILL NEED:

1) to be tall
2) to have a magnetic nut/bolt tray
3) to have a small socket set (mine's a Teng one)
4) Patience, and the ability to think logically.

The air filter's to the left of the oil filler cap, beneath that black plastic cover. Most of the disassembly and reassembly of the car is to allow access to the nuts and bolts at the rear of that cover.

PUT YOUR MAGNETIC TOOL / NUT TRAY ON THE FRONT R/H HEADLIGHT, AND OFF WE GO.

First task - to remove the pollen filter housing.

a)Remove the rubber trim from the bulkhead area surrounding the pollen filter holder. Front and back. NTR
b)Remove the plastic mesh that's held on with 5 x turn screws, again surrounding the pollen filter (about 3 feet long) NTR
c) Remove the plastic ducting on the left and right of the pollen filter housing (about as big as your hand). They just clip out. NTR
d)Undo the 2 x 13mm steel nuts in front of the bulkhead on the left and right. (one is directly behind the washer bottle)
e)Slide out the pollen filter assembly complete. (it's big and heavy) and lay on the floor. NTR

Now you can see the entire top of the engine.
Next is to remove a bit more of the LHS plastic area around the wiper motor to allow more access.

f)Climb on top of the engine, and remove the bottom wiper motor nut, and 2 x 10mm(ish) bolts from under it. There's one more, on top, near the bottom wiper motor nut.
g) Bend, and force this piece of plastic out of the way, as you need to to gain access to the hex nuts on the air filter cover. NTR
h)Remove the flexi ducting from between the front of the air filter cover and the radiator cowl. (about 3" diameter) NTR
i) Undo the 5 (yes 5) hex nuts from the air filter cover. The rear LHS one will mean YOU being ON the engine again. The hex nuts can't be lost, as they're attached to the cover.
j) Remove the oil filler cap, and lift off the air filter cover. NTR
K) Replace the air filter, and reassemble in the reverse order. NTR

When re-installing i) above, start with the 2 hex nuts on the left, as they are awkward to do otherwise.

I read elsewhere that it's easier to do this with the washer bottle removed. After doing this, I don't think so really.

Target time - 50 minutes.
Print this out, and be methodical.

Tim.

[Sports Junkie]

I just completed this on my 3.0d and agree with the method above except I don't believe you need to remove the wiper motor although it may be different with LHD cars v's RHD.

I was able to get at all the hex head bolts using a standard allen key. Still very fiddly and probably more difficult to reassemble. If you have to force anything your doing it wrong. When you eventually get the angels right, it all just slips together again.

[motordavid]

Different strokes for different...
just wondering why one would go through this process for a "replacement"
K&N air filter, when an oe part performs well and takes about 3 mins to replace.

The "improvement"/difference is barely noticeable by most accts. and, the
performance increase is suspect. That is some serious DIY procedure for an
air filter, imo.
GL,mD

[Sports Junkie]

Different car dude, we are talking about the diesel..