Hey all,
After months of research, a lot of which had to be done based on Abarth/Fiat 500s because they have more online content, I decided to start working on making my Panda quieter. I want to limit a bit the road noise, to have a bit of a more comfortable drive.
About the materials, I decided on a layer of CLD (1.5 mm alubutyl) on the metal, and a layer of Reckhorn DV 10I sound isolation fleece (to absorb instead of deflect sound). I avoided MLV due to weight.
I have so far done the two front doors, the rear right door, and I applied CLD to the trunk door and under the hood. I'll try to finish the last door this next week, and add fleece to the trunk door as well.
I can already notice some differences in city driving tho, including "small stuff" like the noise the window motor makes, how the speaker sounds, and how the door "thumps better" when closing. After finishing the last door and trunk I'll try to go on a longer drive to see if I can hear any improvement.
Disclaimer: I am not a professional, and I do not actually recommend doing this to your car. You would probably void warranties, or potentially introduce water ingress, or potentially break parts. I will not be liable in case you damage your car or anything else bad that happens . This is just for educational purposes, and/or for other people who are trying to sound deaden their car and might find my experience useful in some way.
These are roughly the steps I followed when working on the door:
1 -> Remove plastic covers on the door unlock and pull handles, and remove the screws (M5 hex on mine). The front doors have two additional screws on the side of the door lock (phillips, threaded onto plastic). The window crank needs to come off on the rear doors. You can use a microfiber cloth for that, there are plenty of videos online of that. Careful not to lose the clip that holds the crank in place! Additionally the front doors have a plastic trim where the mirror adjustments are, these can be easily pried off with a plastic trim tool.
2 -> Carefully pry the door card away with plastic trim tools, carefully unclipping it. You should consider grabbing some spare clips if your car is older, as the plastic becomes brittle over time. The clips are on the two sides and on the bottom of the door card.
3 -> The door card hangs on top. You need to "slide it up" to unclip it. The part it clips onto might come off with it, it's just the window rubber seal, just put it back on the door if that happens.
4 -> Next step is disconnecting the door lock actuator. It's hard to describe this, so try watching a youtube video. After that the door card is finally free, but make sure none of the clips remained on the door.
5 ->
This step is not reversible! I am not suggesting you do this and I won't be liable if you damage your car! The vapor barrier (white foam) needs to either be cut to allow working, or needs to come off completely. I imagine resealing it with tape would not last for long or would not be water tight enough. I decided to remove it completely and make a new one. The removal is pretty easy to do either by hand or with a scissor/blade, just be careful with the paint.
6 -> Now that the vapor barrier has come off, you also need to remove the glue (or maybe it's also butyl? idk) that held it in place/sealed it. My car is relatively new and this was pretty easy to do. I simply started pulling the material, and it seems to lose its stickiness when stretched. It would occasionally break as I was pulling it off, but I would just "restart" pulling it when that happened.
7 -> Clean all the surfaces where you intend on applying CLD. I used brake cleaner for that. Be careful not to strip the window rail or other moving mechanisms from grease.
8 -> Apply the CLD. Larger sheets are usually more effective than smaller sheets put together. I went for almost full coverage since the door panels have pretty good access. The doors are much heavier due to this.
9 -> I applied CLD around the speaker too because I wanted to make sure water didn't leak from the mount.
10 -> Time to make a new vapor barrier. Make sure the surface is clean with some brake cleaner. I replicated the factory seal with butyl rope. (6mm, 8 meters was enough for all doors). You can stretch the butyl rope as you apply, so that it is not too thick.
11 -> I use the door card to cut thick plastic sheets to roughly the same size. I then start sticking the plastic sheet to the butyl rope on the door, starting from the bottom.
It's very important not to let the plastic sheet fold when sticking it to the butyl, as that might allow for water ingress. It was inevitable that the sheet folds, I just tried to ensure it folds on the top part, instead of on the bottom where the water drains to.
You also need to make sure that you have enough slack since parts of the door card protrude "into" the door.
You need to make two cuts to the sheet, to route the speaker cables and door lock cable out.
12 -> I cleaned the door card on the inside, and applied some sheets of CLD. I went light since I don't think plastic resonates too much.
13 -> I installed the insulation fleece to the door card, being careful so that it isn't applied too thick. I tried to keep it lower or at the same level that the clips are, to prevent fitting issues. I also kept the areas around the door handles clear, where the screws are.
14 -> I added some 2x5mm soft foam tape to the door to prevent it from rattling, around where left/right and bottom edge of the door card. I also added some 1x5mm foam tape to where the clips are retained, to prevent them from rattling.
15 -> Time to reinstall the door card. You just need to do the reverse of what you did when removing it. I had issues with one of the clips, where it simply refused to clip in all the way. It had deformed and was not "springy" enough to remain clipped in. I also had an issue where one of the doors came with a clip missing.
16 -> Screw the screws, and install the crank again.
Some pictures:
Our Panda is very noisy on the coarse chipseal roads here. Made worse by most of our running being at 90-100 km/h.
