weird cabin noise

[goodfella]

I have had an annoying dull knocking/popping sound in my bora cabin for about 3 weeks and its really starting to drive me crazy...

Imagine a loose pen rolling in the empty glove box or a loose wire swinging and hitting the inside of the door trim... the noise is most noticeable when coming to a dead stop it continues for about 5 secs then goes quite.

Well tonight I stuck my head in the front passenger footwell and had a good listen, shaking the car and listening for obvious noises...nothing. So then I decided to start the car, and there it was. I removed some of the underdash trim and felt what I think is part of the climate control system, a hard plastic box like thing and I could feel a gentle knocking in it in time with the noise.

SO I think its the vent/air direction actuator either sticking or on the way out.. Can anybody tell me if they have seen or heard of this happening before and how I might fix it, either lube or replacement.

Cheers in advance....

[McDub]

ahh don't you just hate rattles!
my passenger seat has this rattle like there's a box of screwdrivers hidden in the back of it. no idea what it is, but something feels loose in there, maybe the side airbag, i don't know

sometimes my passegner door likes to make a rattle, and i reach across and just smash it with my fist.
the dash too actually.
oh and the rear of my car when i reverse up a driveway bends and creaks like a rusty door.... grrrrr

[goodfella]

other suggests range from industrial foam to insulate the sound to upgrading the stereo.

[dubbed]

haha how bizarre. I posted this exact problem one or two days ago... I believe the culprit is the climate control motor that changes fresh air to recirculate. It looks like a bastard of a job so I'm just leaving it for now - I know it'll cost a fortune for a technician to do as well. I just turn the stereo up now

By the way, try leave the car off but have the ignition on accessories and see if it still makes the noise. Mine does.

[madglf3]

I have a few weird ones, whenever I open the car there's one for a few seconds after I open the door to after it's closed (door mechanism humming?), another one that sometimes sounds like it's in the glovebox clanging and a really annoying recent one that is coming from the centre console it seems. I'd like to get to the bottom of them but wouldn't know where to start.

[goodfella]

haha how bizarre. I posted this exact problem one or two days ago... I believe the culprit is the climate control motor that changes fresh air to recirculate. It looks like a bastard of a job so I'm just leaving it for now - I know it'll cost a fortune for a technician to do as well. I just turn the stereo up now

By the way, try leave the car off but have the ignition on accessories and see if it still makes the noise. Mine does.

Hey, sorry for double posting, I missed yours. I'll listen out for the noise after turn off.

[JustCruisn]

I have a few weird ones, whenever I open the car there's one for a few seconds after I open the door to after it's closed (door mechanism humming?), another one that sometimes sounds like it's in the glovebox clanging and a really annoying recent one that is coming from the centre console it seems. I'd like to get to the bottom of them but wouldn't know where to start.

Fuel pump is primed when the door is opened, that is the humming noise = Normal

The other noise, AC thing, well I'm looking into that. I think I have found the problem but just need to confirm the part numbers and get a price.
I'll post my findings soon, very busy lately.

[goodfella]

The other noise, AC thing, well I'm looking into that. I think I have found the problem but just need to confirm the part numbers and get a price.
I'll post my findings soon, very busy lately.

Looking forward to your findings!

[moniker]

Looking forward to your findings!

I had a noise a bit like that.
Turns out I had a screw rolling around in the bottom of the airbox, kind of behind the radio near the firewall.
Was a bit of a dog to get out, I think I ended up using a magnetised screwdriver, coupled with lots of swearing...

I'm not sure where the screw came from , although I do get a flapper motor fault code on the VAG-COM, although it does still seem to work okay

Good luck

[madglf3]

Fuel pump is primed when the door is opened, that is the humming noise = Normal

The other noise, AC thing, well I'm looking into that. I think I have found the problem but just need to confirm the part numbers and get a price.
I'll post my findings soon, very busy lately.

Thanks for that mate, good to know.

Off topic slightly: You should come along to the photoshoot coming up mate, it'd be good to have another mk4 there.

[Jmac]

Yep and i can have a listen to your noises FTW!!!!
Just look for the guy in the A4 with the discreet CC sticker on his window and he speaks a little funny
Jmac

[JustCruisn]

Jmac

Can you bring your vag-com and laptop to the photo shoot ?
It would be interesting to see if a code has been thrown indicating that the air flap is malfunctioning. And maybe it can confirm which motor it is that controls it.

[quozl]

The code thrown is:
01274 - Air Flow Flap Positioning Motor (V71)

This seems to happen randomly on MkIVs and B5 Passats with climatronic. Apparently it's due to the flap sticking after recirculation mode is turned on.

The Bentley Manual says this about it:
Short circuit or open circuit in wiring or connectors to air flow flap motor -V71-
- Check -V71- using function 08 Read measuring value block
- Repair wiring and connectors using wiring diagram

To fix this with Vag-Com:
Log into vag-com, open module 08 (HVAC).
Follow the adjustments ValveFloat outlined here, involving block 002.
Allow vag-com to calibrate the flap, ticking should be gone.

If that fails and you have to replace the physical motor:
The part number is 1J1 907 511 A, costs around $120. Here's the Bentley blurb for it:

- Remove glove box.
- With screwdriver, carefully unclip air flow flap rod from lever.
- Disconnect electrical connector.
- Remove screw.
The flap motor is connected to the evaporator housing portion of the heating and A/C unit. To prevent damage:
- Lower flap motor and at the same time pull off fresh air/recirculating air flap shaft.

Replacement flap motors are supplied in the "recirculating air" position. To ease the installation, first do the following:
- Connect electrical connector to flap motor.
- Switch on ignition.
- Operate button for fresh air/recirculating air.
When the center position has been reached:
- Disconnect electrical connector from flap motor.
- Insert flap motor in fresh air/recirculating air shaft.
If the flap motor cannot be attached to the fresh air/recirculating air flap shaft, remove fresh air blower -V2-, and attach flap by hand.
- Turn flap motor and tighten bolts.
- Attach operating rod for air flow flap.
- Initiate Basic setting, function 04, Climatronic, OBD.

reproduced from VWVORTEX

Cheers Al

[dubbed]

Good info, Al. Although I'd think the installation would be different to RHD v-dubs.

[quozl]

As far as I'm aware they are in the same position but I imagine one of our esteemed VW trained techs can tell us one way or the other.

Cheers Al