I do a lot of highway driving in my TD and the noise is driving me nuts. When I first installed the motor I had a cone filter instead of an airbox. That was quite loud. Now I installed the proper airbox and it got a LOT quieter below 3000 rpms, but at 3000 and up it's still pretty loud. Mostly at 3000 rpms.
I dont have the snorkel that goes into the fender yet. Does that make an appreciable difference in noise? According to the bentley manual it does.
Here's the pieces I'm missing. #18 and #19.

Does anyone have this laying around they'd like to sell me?
My friend with a Westy TDI swap just installed plumbing from the air box to the body cavity/upper D pillar vents and it got a lot quieter, way less turbo noise, he used some flexible dry ducting, fwiw.
you could probably try using some pink insulation underneath the air filter box. its probably vibrating and rubbing against the metal. I actually had a nasty vibration with my airbox, and when i removed it, it was gone... but the motor got louder with the cone filter :twisted: i kinda like the noise the car makes... lets you know just how hard she's working and at what rpm she's at (probably not so great on really long trips though)
yeah mine is loud too with a cone filter but then again I spin 34xx to do 75, I have a longer trany im throwing in soon so some of my noise will go away... also I like my music to make small vibrations (not rattle car vibrations) so that covers up most other noises
Yeah, I ran it with out the snorkel because the pipes
were shot....... I found it to be very very loud too.
I still haven't fixed it.... I would really like to run
a 3" pipe to it... and adapt it...(it is an N/A)....
but in the mean time I slapped the elbow into the
airbox... and in just doing that it helped considerably.
I would stay away from the pink insulation.......
it grabs moisture.... like a sponge..... what you might
possibly try is to take a look at this stuff called "Sill Seal"
It is used in construction what setting a house on a
foundation... It is 1/2" thick x 6" wide.. basically it gets
crushed between the house and the concrete wall to seal
out drafts.
it is some kind of poly foam... but it is flexible enough to wrap around
something...
yea true... that sill seal stuff comes in this big roll and its pink. shouldn't be too expensive... and yea it wont go moldy

use some kind of glue to glue it to your car or the actual piping and all should be well