I recently decided to do some quick interior cleanup, which has of course resulted in almost complete disassembly of the entire car. With the dashboard and HVAC out I was cleaning up all the dust and crusty insulation, and I came across this:



The entire firewall has this really nice mass-backed rubber and this jute type material. The jute, however, has not fared well after 40 years. It's so crumbly that it turns into dust (not just dust, but dust so thin it looks like smoke).

Now I could remove the whole thing and chuck it in the trash, but I'm betting the jute & mass-backing help cut down on a lot of noise and heat. I'd like to replace it but this piece is pretty elaborate and looks hard to replicate.

Has anyone replaced the jute with something else, and if so can they recommend a good material? I'm thinking of removing the old jute and any glue residue, then there are two options:

1. Replace it with some newer comparable material and glue it to the rubber

2. Cover the areas of the firewall normally covered by the insulation with closed-cell foam, then put the rubber backing over top.

Any suggestions are welcome

 

Never tried it on the firewall, but how about some self adhesive sound deadener
they use on the floor?
Just an example:
https://kilmat.com/products/

 

try this,

 

Summit Racing has a large selection of heat shield and sound deadening insulation products available (https://www.summitracing.com/search/...deadening-mats).

 

I think I used DEI Under Carpet Lite and attached it to the OEM rubber mat. I did this in two places - the hatch mat and the mat underneath the storage bins.

Also Sarah-n-tuned rocks. Can't wait to see her Celica with the V8 running soon.

 

agreed, its going to be really great

 

I did end up purchasing something for this job that looks like it will work well, but the point has become moot for the time being. First though I want to thank everyone for their suggestions

CLD is great and I was going to put down a layer of that first, but it performs a different purpose than the jute insulation. The CLD is designed to stop resonance and vibration whereas the jute blocks more sound and heat.

I actually almost went with jute, but I was kind of concerned about finding a good adhesive to keep it stuck to the rubber. I've tried that in the past on other areas and it ended up separating.

Thanks for showing me this channel, I've never seen her videos before. I'll have to give more of them a watch later.

Those are both similar to what I ended up ordering. I'd been meaning to try this stuff from Resonix for awhile now, and the fact that it was on sale sealed the deal: https://resonixsoundsolutions.com/pr...tion-material/

Unfortunately there seem to be bigger problems. I noticed the back of the mat was wet when removing it, and then I found this:



Water leaked from the corner of the windshield cowl area down and soaked the mat. It must have been leaking for some time and been trapped there rotting the firewall. I pulled all of the insulation off with my hands.

No holes yet, but this is clearly going to require a lot more disassembly and repair than I expected. Particularly since it also seems to have leaked down to the floor and started some rust there, requiring me to strip back the CLD and the undercoating. At this point I don't expect to drive the car this summer at all, but it's better that I found it so I can't be that upset.

Thanks everyone for your suggestions. When the time comes I'll report back with how well the Resonix stuff works