Taking out the front vents

[kevinkw]

I have a 99 C4, and there's been a rattle coming from the front vent area for a while now, but recently it has gotten much worse, even on roads that are semi-smooth.

Is there any instructions on this? I think you have to take off the A pillar trim, the side vent covers, and the alarm cover to get to the 2 front vents right? Is there step by step for that?

Also the seat belt mechanism that slides up an down rattles on the passenger side. If I get someone to press it, the noise stops, any idea how to fix that?

Edited December 8, 2008 by kevinkw

[Loren]

Please try a search - these have been covered many times.

http://www.renntech.org/forums/index.php?s...ost&p=14785

[kevinkw]

Thanks Loren,

It looks to be a multi-parter.

First the side vents

http://www.renntech.org/forums/index.php?s...amp;#entry14785

Then the A Pillar trim

http://www.renntech.org/forums/index.php?s...5&hl=pillar

Then finally the defrost vent pieces

http://www.renntech.org/forums/index.php?s...082&hl=vent

Edited December 9, 2008 by kevinkw

[kevinkw]

Ok, a quick update, especially for someone who's never taken trim off of their cars before.

I just did the passenger side, and plan on driving it to work with all the pieces removed and see if the noise goes away.

1. Taking the side vent out was easy. Just follow the steps in the linked post.

2. Removing the long A Pillar trim piece was a little bit harder, especially since there's no pictures I can find. You need to pull up on the hanger piece that rests above the seat belt on the B Pillar. Just pull up and out. Once that is removed, put your fingers in on the top side of the A Pillar trim out, rocking it out and slightly up. I worked from the back to the front. Where it joins the vents, it is clipped to the defroster vent, just slide it out.

3. Taking out the alarm cover. This is tricky. There are 2 plastic posts keeping the alarm cover in place. Push it forward towards the windshield before you pull up, otherwise you will break it. I broke one of the two, but it is easy enough to glue back on. It is a very small small piece of plastic.

4. Pry out the defroster vent piece. I started out at the door and worked my way in. It was pretty easy until I got to where the alarm cover used to be. The 2 posts on the alarm cover seat (that also clips to the alarm cover plastic posts) overlaps the vent. I yanked a little too hard, and that broke off. Luckily I found it, and easy to glue back on.

Underneath the vent, there is a long strip of black plastic that the vent piece touches. There are a lot of places where the two rather flexible pieces of plastic comes into contact, I think the noise is coming from those two pieces vibrating against each other on rougher roads.

Another suspect is the plastic pieces that joins wires together along the A Pillar.

[kevinkw]

There's still some rattling sound, but I couldn't tell if it was from the black plastic parts underneath the vents vibrating against the metal or because I didn't take apart the driver side.

Any ideas?

Otherwise I will just put in as much felt and double sided mounting tape between the two slabs of plastic, and call it a day.

Edited December 10, 2008 by kevinkw

[Q-Ship986]

Rattles drive me crazy and I have hunted down more than a few in my day on many cars. Squeaks and rattles are often eliminated by using foam or felt tape in strategic areas. Car companies also use specialty lubricants like Dupont Krytox. My advice is to continue to try to isolate the source/area of the noise. If you remove potentially offending trim, examine the placement and wear of any foam/felt tape. Look for missing or broken mounting tabs and fasteners. Take the car for a drive without the trim installed, perhaps do so for each piece you remove, one at a time. Replace or re-fit any foam/felt tape. Apply a very light amount of lubricant (I like Krytox and/or dielectric paste) to suspect components. These steps usually work. --Brian

[kevinkw]

Rattles drive me crazy and I have hunted down more than a few in my day on many cars. Squeaks and rattles are often eliminated by using foam or felt tape in strategic areas. Car companies also use specialty lubricants like Dupont Krytox. My advice is to continue to try to isolate the source/area of the noise. If you remove potentially offending trim, examine the placement and wear of any foam/felt tape. Look for missing or broken mounting tabs and fasteners. Take the car for a drive without the trim installed, perhaps do so for each piece you remove, one at a time. Replace or re-fit any foam/felt tape. Apply a very light amount of lubricant (I like Krytox and/or dielectric paste) to suspect components. These steps usually work. --Brian

I have driven with the A Pillar trim, side vent, speaker, and defroster vent out. The rattle is still there. Any ideas at all?

[kevinkw]

I drove it around a little more today and the noise seems to be coming from underneath the vents. I jiggled with the AC ducts, and they seem to be pretty loose where they join. However, they are really hard to get to. I don't think I can maneuver myself in putting some mounting tape where they join through the side vent.

Any ideas?

[1schoir]

I drove it around a little more today and the noise seems to be coming from underneath the vents. I jiggled with the AC ducts, and they seem to be pretty loose where they join. However, they are really hard to get to. I don't think I can maneuver myself in putting some mounting tape where they join through the side vent.

Any ideas?

Kevin:

If you really can't reach it, and don't intend to go further by perhaps removing the dashboard, have you thought about spraying some type of expanding foam or some silicone sealer around the place where the two ducts meet (by means of on of those long nozzle applicators)?

If you are going to try the expanding foam, use it very sparingly and use the kind that does not exert so much force when it expands that it bows the window and door frames.

If you can put it in the right place, it might solve your problem.

Just a thought.

Regards, Maurice.

[BruceP]

I didn't catch which side this was on, so I don't know if this is helpful, but in case: I had a rattle in the dash on the passenger side, which my ears told me was coming from the vent. It turned out to be something related to the passenger side airbag, for which there was a TSB. Don't know what they did, but it worked.

[kevinkw]

Hey Bruce,

Yeah, the airbag TSB was the first one done.

I ended up going under the dash in the footwells. There's a couple of places where the AC ducts meets the metal parts under the dash. I placed some felt tape where they come in contact, we'll see if that solves the problem.