I just had my car painted and I have not yet replaced the pad under the hood. It's nice and clean under the hood right now. I'd like to deaden the sound as much as possible. I know the standard pad will help. But, will butyl sheets mounted to the underside of the hood prior to installing the pad also help?

I have some of this lying around.
https://www.amazon.com/gp/product/B0787XL7G6/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I think you will have more success to quiet things down in the cabine when you apply it on the firewall and transmission tunnel. I installed it in the trunk (spare tire) and rear doors in my 300SE and it definitely subdued the road noise.

This is what I used, also available in black: https://www.amazon.com/dp/B00URUIKAK/ref=sspa_dk_detail_7?psc=1&pd_rd_i=B00URUIKAK&pd_rd_w=PVeZh&pf_rd_p=45a72588-80f7-4414-9851-786f6c16d42b&pd_rd_wg=kdCol&pf_rd_r=EVA1R8Y3V62YGCB9931E&pd_rd_r=0daeb4b9-4a93-41a7-a029-b7cff1abec0e&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzNDVHSFNCWE9WRUxHJmVuY3J5cHRlZElkPUEwMjYwNDA3MjE0S1BWNlU4VlFVNSZlbmN yeXB0ZWRBZElkPUEwMDI5MzE3MzdLTEw1OFNHSkRUUSZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZ kb05vdExvZ0NsaWNrPXRydWU=

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1979 Black on Black, 300CD (sold), 1990 Black 300SE, Silver 1989 Volvo 780, 1988 300CE (vanished by the hands of a girlfriend), 1992 300CE (Rescue).

Your vehicles are absolutely beautiful!!

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Don't you have to have the transmission out to install it in the tunnel?

Putting it on the firewall sounds like alot of work since there are so many components attached.

Where in the trunk do you think it was most effective?

Gregp1962, I think he's suggesting the inside of the car under the carpet. I did this to my 300TD that I rebuilt basically from body in white up. Finally, an intro to the 300TD manual project.

You can put this stuff on the underside of your hood, but understand the adhesive on the butyl stuff might soften and let go when hot, either from the engine or the sun...this piece of metal gets heat from both directions. When you put on the foam factory style pad, it's applied with a spray on adhesive that pretty much hardens with heat...as opposed to softening.

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1983 W123 300TD US spec Turbo engine, with Euro bumpers and manual climate control, and manual transmission.

I'm going to have my carpet out soon. I'll see how much buytl is on the floorboards and maybe add some on the transmission tunnel. Is butyl the best for this part of the car?

Has anyone known of buytl coming off the underside of the hood due to heat?

I installed an oem hoodpad recently and noticed quite a difference in the noise level, not so much inside the car but def outside. And with rubber cement, the hood pad is nice and secure. I think adding a butyl layer would be unnecessary.
If you have the carpet out def use the butyl where you can.

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DS
2010 CL550 - Heaven help me but it's beautiful
87 300D a labor of love
11 GLK 350 So far, so good
08 E350 4matic, Love it.
99 E320 too rusted, sold
87 260E Donated to Newgate School
www.Newgateschool.org - check it out.
12 Ford Escape, sold, forgotten
87 300D, sold, what a mistake
06 Passat 2.0T, PITA, sold

Las Vegas NV

The stuff you have would be great for the firewall and trans tunnel.

My concerns on the stuff coming off are just based on logic, I'd also be concerned about the weight it would add to the hood. This stuff is not light.

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1983 W123 300TD US spec Turbo engine, with Euro bumpers and manual climate control, and manual transmission.

I gather a pad also protects hood paint from engine heat. The paint on my 123 is pretty nice. I pulled the old pad off, was falling off in big pieces. I haven’t driven it much since then - will install a new pad soon.

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1986 300SDL, 362K
1984 300D, 138K