I'll send $20 to whoever can give me advice that leads to solving this problem.

 

Have you checked out all the parts that are involved with it? Maybe one part broke and it's not opening all the way. My theory is that it's only opening half way and that's why it's making that sound. Because the other half that's still sticking out is going against the wind and it's making that sound. Just like how side mirrors make wind noise, I think it's similar to that. It might just need a little lube.

Mine is a '99 and it still works perfectly but I never use it so maybe that's why.

 

The recirc door is operating properly and covers its full range of motion that I can tell. Climatronic throws a fault for this motor every once in a while, but it never records a fault when the sound happens, so I don't think it's related.

As far as I can tell, the cowl is installed properly, as well as the battery cover.

 

It's a two-part door, outer and inner. The inner is a smaller, same-shape door tucked inside the outer door. The part you can see from above sealing the intake is the outer door. You would be able to see both doors from above with recirc off. One motor with two track "slots" moves both doors, and both of them are closed briefly when passes through the center of its range. I believe if it fails to move the inner door properly you can get in a spot where the blower can't draw air from inside /or/ outside. That might be what you hear, kind of like a vacuum going nuts when you hold your hand over the inlet. On a properly working Climatronic Passat, you can hear this very briefly when changing modes while the blower is maxed (like in summer), a half second's pause in airflow.

So, is it moving any appreciable amount of air through the vents when recirc is on? I bet not, or at least it's a lot less.

You can't really see the inner door operating from the pollen vent side. You would have to pull the glovebox and possibly the blower motor (can't recall). Sounds scary, but it's a 10 minute job unless you fuck up the Rubix Cube glovebox light when taking it out. Make sure both doors get all the way up and all the way down. I bet your inner door won't come up. Check to make sure it's engaged with the motor track properly.

 

There is a post somewhere on here that shows how to remove the radio, climatic control, and cover plate.

I'd remove what I could then plug climatic back in and try and get a better idea where the noise is originating from. Might be able to see the arms, cables, etc., that control the door, see if they are moving correctly, etc..

I haven't been in that area myself. Just an idea to throw at ya.

 

I appreciate it greatly. However the recirc door is visible under the pollen filer after removing the battery cover. I can visibly and physically confirm that it is closing tightly and that the foam gasket on the door is in good condition.

Keep 'em coming guys! :beer:

 

Also, as a note, the howl increases with speed and is nonexistant when stopped at idle.

 

Does it make the same noise while you are parked? or only on the move?

If it is on the move only, it HAS to be the door that closes to suck the air from the inside. (Vent?)

If the door/vent does close, then there is a seal that goes around it that is lose/cracked/worn or not inline.

My Camaro had a manual lever for the same idea (1978) made the same noise while driving only. I can't tell you how to check it or where it is, but that is my educated guess.

 

bump

 

i have no sound at work, ill take a listen when i get home later

 

no clue

 

Thanks for looking. :beer:

Does it make the same noise while you are parked? or only on the move?

If it is on the move only, it HAS to be the door that closes to suck the air from the inside. (Vent?)

If the door/vent does close, then there is a seal that goes around it that is lose/cracked/worn or not inline.

My Camaro had a manual lever for the same idea (1978) made the same noise while driving only. I can't tell you how to check it or where it is, but that is my educated guess.

Yes, there is no sound when the vehicle is stopped with the engine idling. There is only sound at 25+ MPH and it sounds like a hurricane above 70. I'll triple-check these things, since it's easy to do and will be a cheap fix if it is. But like I said, I've already confirmed that the door closes tightly and that the seal on it is good. I guess it could be the seal on the pollen filter box, but that should have just been repaired/replaced when I took it in for the P9 and R5 recalls a few months back. The service they did made no change in the sound. But I guess it's entirely possible that they looked at it, checked it off as okay, and never even really worked on it.