Lower Air Box / Snow Screen Removal for NB

[JackBak]

For all those who would like to do this read on...

OK, here it is instructions for removing the infamous snow screen on a
2000 NB TDI.

Time: Allow about 3 hours from start to finish.

Tools: Long Handled #1 Philips Screwdriver (may not need)
Channel Pliers
10mm Wrench
10mm socket with extension
Torx T-25 bit
Short screwdriver type holder for T-25
Regular length screwdriver holder for T-25
Tire Iron (17mm socket)
(Possibly) anti-theft adapter for wheel lug bolt

Procedure:
- Remove Left front wheel/tire (driver's side in USA). Use
Jack stand(s) and block rear wheels, etc. Take proper safety
precautions.

- Remove exposed wheel well skirt. Use regular length
screwdriver holder with T-25 driver for 13 screws, the 14th
and last T-25 screw will need the short handle as it is just
to the right of the suspension spring.

- Under the front bumper you will now see a "U" shaped
assembly. Bear with me as I describe this assembly and then
you will see how I call it a "U" shape. Assume you are
sitting facing the wheel well with the disc brake at about
stomach level. Now if you look directly up into the wheel
well at about the 11 or 12 o'clock position you will see a
black hard plastic pipe about 2.5 inches (64mm) in diameter
with a flared end to it. This is the end of one of the "U"
assembly's arms. It is the air intake before it enters the
snow screen box. Follow this tube down to find a box-like
black plastic assembly. This is the box that contains the
snow screen and is at the bottom of the "U". Note that on
its side is a spring loaded door that opens into the
box. The other arm of the "U" is just barely visable from
your vantage point, but this is the tube that will become
the input to the filter box in the engine compartment.

- Remove the 10mm nut holding the snow screen box brace to the
body. Now remove a 10mm hex head screw that holds the flared
air intake tube to the body. At this point the air intake
arm and the snow screen filter box may be wiggled loose from
the other arm of the "U" going up to the air filter box in
the engine compartment.

- At this point I went top-side into the engine compartment
and removed the air filter box, disconnecting the MAF sensor
plug, etc. BUT in hindsight I don't think that is really
neccesary.

- I was not able to get the flared tube and snow screen box
(they are clamped together with a short piece of rubber
tubing with two compressable tubing clamps - thus the
channel pliers in my tool list) out without removing a
fender support brace. If you can get at one of those tube
clamps you could separate the flared air intake tube from the
snow screen box, but I couldn't and had to remove this short
3 inch (76mm) brace - two T-25 screws.

- Now that the snow screen box is out and in your hands you
can look down into the box and see the screen. It looks like
fine nylon panty hose. You can now also see how when this
screen gets totally crudded up the spring loaded door in the
side of the box will open due to air pressure and totally
by-pass this snow screen. What a .... design.

- By carefully prying the top of the snow screen box off its
base the snow screen itself may be lifted out and cleaned or
thrown away (I chose the latter). In 1500 miles of spring
driving my screen was 33% clogged with dust and weed fuzz
that my K&N filter could easily have trapped if it actually
made it all the way up there.

That's it. Assemble in reverse order. Remember this description applies
to a 2000 New Beetle TDI.

Enjoy.

-Jack

 

[Karl Roenick]

I worked on the lower airbox today and would like to add:

1. I didn't jack up the car, just turned wheels to left.
2. I removed enough fender liner screws to peel it back halfway.
3. I took off the brace (T30 screws I think), brought the assembly into position where I could get some channel locks/vise grips on the clamps to take it apart.
4. Removing the turn signal, as Mickey has stated, definately helps and it is easy. Pry off the tiny tab on the lower right hand corner and remove the Phillips head screw.
5. I chose to clean the screen. I have about 13,000 miles on the car and it didn't seem that wickedly blocked. I used a vacuum and backflushed with water and vacuumed again.
6. Reassembly was harder, especially the clamps and alignment. I used a vise grips and kept the clamp tangs down for future access. This part would go faster if the wheel had been off.

I restored the system to its original configuration for several reasons:
1. The intake is about a foot higher in a more protected place to help avoid ingestion of material/liquids.
2. I think every 20,000 miles might be okay for me. That's not too bad.
3. I'd like to do a little more research and hear from others' experiences.

The intake path is truly tortuous. Removing the lower box and snorkel is tempting. Also ripping out the screen, if it's not needed, is inviting, as Jack did. (I didn't see a way to non-destructively take apart the box.) I would like to find out the thinking behind the vw design first.

 

[JackBak]

Karl,

I agree that ripping out the box altogether would accomplish the same things BUT lower the air intake by 12-18 inches... not good. That is why I took particular pains (read multiple small screwdrivers) to pry the box apart, pluck the screen out and reassemble all the bits. My air intake tube is still the same one and in the same spot as the day I picked it up at the dealers.

Any crud that actually makes it up to the upper air box will be caught by my K&N filter, whereupon I will clean it.

Others may not want to remove the filter, OK. As an engineer of thirty years I question much and think through everything I do.

-Jack

 

[Karl Roenick]

I did not think it was possible to disassemble the box. The technique involve putting the muliple small screwdriver in the slots in the joint to relase the tabs? I thought it might have been glued. So if you want, you can always put it back together again.
Jack, could you please expand just a tad on your technique of taking the thing apart?
Thanks
Karl

 

[JackBak]

Sure thing Karl,

When looking a the mating surface of the two halves of the box you see many plastic interlocking tabs. By the way a similar technique is used by those wanting to open that R109 relay. I started at the air output end of the box and carefully pryed apart several tabs with small flat bladed screwdrivers. Then I eased this portion of the two halves apart (not apart by 1/4 inch by just barely past the locking point of t the tabs). You then work your way around the periphery until it just kind of pops apart. Pluck the screen out (I've still got the screen - I could clean it and put it back in but I'm not going to) and press the two halves back together.

As for the R109 relay the easiest way is to use four small brass shims to hold the tabs away from the base and pull the two halves apart.

Cheers,

-Jack

 

[Karl Roenick]

Cool. Reversible.
Thanks.
Karl

 

[Thomas Babb]

delete

[ May 03, 2002, 08:43: Message edited by: Thomas Babb ]

 

[Karl Roenick]

I feel like taking the box out again to see if I can take it apart like you guys......not!

 

[Karl Roenick]

Well I removed my NB's lower airbox screen.
Took about an hour. Definately much faster the second time. Since it's only been about a thousand miles since I cleaned it, there was not much crap on it. Some though.

I looked at the mass air flow before and after screen removal. This is a cool engine, egr deactivated, clean screan. Both times it was 5300 mg/hr. Perhaps a tad more without the screen, maybe 5350. Placebo land at idle anyway.

Thanks Jack.

 

[JackBak]

My pleasure Karl. Just wanted to give back a little from all I've taken from this forum.

-Jack

 

[The Trouts]

Here are pictures of a successful removal and dis-assembly of a lower air box on a 2001 NB.

I followed the advice in this post and did the following:

1. Put car up on my wooden ramps
2. I turned the wheels all the way left
3. I removed the one screw holding the horn assembly to its mount.
4. I removed the drivers front turn signal.
5. I removed seven Torx screws in the wheel well and peeled back the plastic piece.
6. I removed the 3" bracket.
7. I removed the hex bolt holding the lower air box and the screw holding the snorkle to the body (up above)

8. I removed the snorkle and lower air box as one piece and then disassembled them using a vise grip for the clamp and a slotted screwdriver to pry apart the airbox.
My Hi-Tech Garage

Lower Airbox disassembled to show snow screen with gunk and bird feathers in it.

I hit the bird last fall, it went right through my grill.

The screen wasn't too dirty after only 12,500 miles. I decided to clean it and re-assemble it in case I hit another bird!

Access through the drivers front wheel well.

Cleaned screen ready for re-assembly

I didn't have to remove the wheel or remove anything from above. I am not terribly handy but I am persistant. It took me about an hour.

Thanks to you guys who posted here with instructions.

[ November 02, 2002, 17:17: Message edited by: The Trouts ]

 

[BENFICA251]

what do you do on raining days?

 

[VelvetFoot]

If it would be waterproof air wouldn't get in.

What I'd like to know is how the bird got in under the fenderwell liner where the intake is?

 

[rpmjunky]

good info...
what i like to know is that if this snow screen is present on all tdi cars and/or any other engine types???

 

[Stampfan]

RPM junky: this description on on the NB (and an excellent one at that). For removal from the Jetta/Golf, its a heckuva lot easier. See here:

http://pics.tdiclub.com/video/cincitdi/index.html

 

[Stampfan]

Anybody ever considered just drilling some holes in the box itself so if the screen gets filled, enough air still gets in there? Seems like a nice compromise between removing the screen/box entirely and having to clean it regularly.

 

[Stampfan]

Bump.

 

[TDIfor]

Stampfan;

'02 NB

At a GTG a coupla weeks ago, Growler helped me clean out my snowscreen... turns out the NB has a very clever design. The tubing for the air intake loops up and into the driver's side wheel well -- meaning the air intake is facing _away_ from direction of travel, and up high enuf that nothin' gets into it. I have 76K miles, and I think Growler removed half a leaf.

It took about an hour of various curses to get the air intake out and back in ("cleaning" took 10 seconds) and the lesson learned is that I wont have to futz with it again. I dont see how anything could accumulate in it.

On the plus side,I dont have to worry about drowning the engine going thru water puddles -- unless the water is over my tires, I aint gonna get anything sucked into the engine.

You loose any mythical ram boost effect with this design.... but in a rare bit of German rationality, I think they figgered out the NB was not a ram boost kinda car.

 

[jasonTDI]

Unless you live where there are mice. I've done several with a ton of mice leftovers in them.

 

[BudsBug]

I Just removed the grommet at the bottom of the air box. I figure it is 50% of the total size of the hole and it took 2 minutes remove airbox take out grommet going to the snorkel and put it in the bottom of the airbox so if I need to go to the stealership I can put it back just as fast.:-}

 

[Stampfan]

Budsbug:

Based on what was written above, how dirty was your snorkle screen when you checked? Was it worth removing?

 

[BudsBug]

I would not pull it again just pull off the gromet that should provide all the air I can use.

 

[cattlerepairman]

Anybody ever considered just drilling some holes in the box itself so if the screen gets filled, enough air still gets in there? Seems like a nice compromise between removing the screen/box entirely and having to clean it regularly.

I thought that the spring-loaded flap was standard on all model air boxes exactly for this purpose? It opens, once the vacuum in the box reaches a certain limit and provides (unfiltered) air to keep the engine running.

I removed the whole air intake plumbing from my NB. A reusable air filter in the engine compartment, situated behind a heat shield, seems to do a good job. I am aware of the K&N flame war.

I know that in the Diesels, the air intake part plays much less of a performance role than in gasoline engines. However, I, too, was wondering about the rationale behind the multiple-bend, convoluted OEM setup. In the Beetle, it is truly a wild air path - more and sharper bends than in the Golf or Jetta. There must be some reason for VW to spend money on these parts. Anyone who can save 10c in a production car is a hero.

 

[richardtoh]

2000 NB. 200,500 miles.

Removed and cleaned the snow screen for the very first time. Strangely enough, there was nothing big inside to clog the air intake. The snow screen was in black color and I was able to wash away the thin layer of fine black dust particles.

Nevertheless, I am glad I cleaned it. Thanks for all the tips.

Yes, removing the tire does make the job easier.

 

[Pelican18TQA4]

If your fear of removing the snowscreen is hydrolock from going through a deep puddle, rest your fears. The intake at the bottom of the airbox sits about level with the top of the driver's side tire. If you're driving around in water that deep, you'll have bigger problems that hydrolocking the engine. I've removed the whole snowscreen box on all 3 of my NBs and never had any issues (and I've driven through plenty of deep puddles).

 

[Ironforger]

Hey Folks, check out this thread to see good pictures of the NB snorkel/airbox. Fenders removed during bodywork, was good oportunity to work on the snowscreen. http://forums.tdiclub.com/showthread.php?t=145168