Engine Soundproofing Replacement..How-To?

[Sunroof]

Oaky, its time to replace that not so old but not so firm foam rubber rear engine insulation piece on the firewall. I have considered that new aluminum lined sound deadener advertised over the OEM foam. It wil ring longer life and the claim to increased sound deadening is music to my ears with my throatie 2.4.

I have a big airbox to reach over, and its quite clear how the top end is installed but how about the bottom end? Where and how does it attach? Engine out install? I hope not. From under? Is is glued to the fire wall?

I love when you folks gives those step by step instructions. Its like having the factroy manual come alive!! Any help or tutorial is always appreciated and welcomed.

Regards
Bob
73.5T

[JP911]

Caveat: I have a 76, so their may be some differences that I'm not aware of between my accordian-bumper and your long hood.

This can be done without an engine drop, but it's alot easier without the engine in there. I used the new aluminum-lined piece and it looks and works great. Really cleans up the look of the engine compartment.

1. Remove the old pad by prying (carefully) the tabs near the front of the engine compartment. Pull the pad away from the top of the compartment and slide it out of the "pocket" where it is held in the back of the engine comparment. Note that you will have to negotiate getting it around the lid shock(s).

2. Clean up the glue and residual foam. I cleaned it up as best I could, but didn't go crazy.

3. Fit the new aluminum piece by sliding it down into the "pocket" and fitting the lid shock. Make sure it's just where you want it.

4. Letting the piece rest on the top of the engine, take the 3M spray adhesive and spray the top of the engine compartment and the new piece. Carefully press the piece into position and bend the tabs back into place to hold it in. Continue to apply pressure by running your hand over the aluminum piece for about a minute or two. And that's it.

[B D]

Get the vaccum ready for clean up, when you remove it foam will be every where.

[fiminod]

leave it out.

[B D]

Originally posted by fiminod
leave it out.

That was my plan until I saw all the old glue and foam stuck to it, if you try to scrape the glue you will most likely scrape and remove the paint as well on a old car.

[Sunroof]

Great Advise. I was not sure just where the glue points were.
I am dissappointed in the foam because its less than a few years old and already at the upper tabs its crumbling and loosening up. For the few more $$$ more then the foam that aluminum coated piece looks like it will last a long longer and give a better appearance.

I was wondering if I could glue on velcro tabs where the hood shock slots are as a extra measure to keep it in place and tight?
The velcro taps are an easy install.

Thanks
Bob

[JP911]

Velcro is a good idea, but I would use extra adhesive to hold the velcro to the body and the aluminum sheet as any amount of heat will quickly loosen the crappy velcro "peel-back" adhesive. Maybe epoxy or super glue?

[B D]

Most auto store will carry a high temp glue for these type of applications, great thing is it can be used for carpet also where heat is not a worry.

[Paulporsche]

Velcro would work. I would be careful to get Velcro w/o adhesive and use the same glue you use for the rest of the pad. Or use Velcro w/ that same adhesive throughout. I am just concerned that the standard Velcro adhesive is not up to the heat/cold issues over time. Velcro also comes in other than the standard adhesive, so you may find one that is OK w/o having to use another adhesive. You may have to check their website or a supplier.

[DG624]

DOesn't Dynamat make a reflective heat shield for engine compartments? Is the replacement a perfect for the engine area? How about heat reflection and noise reduction?

[TC_SJ]

can you slide the new aluminum pad over the old one ?

[Rick Lee]

I took it out of my Carrera and it's missing in the SC I just bought. It looks fine with some glue residue. Leave it out. It looks worse when a pad gets ratty, it costs about $60, weighs a few lbs., is a PITA to install and makes no difference in sound in or out.

[Crachian]

makes no difference in sound in or out.

I'm about to replace mine because I thought there was a difference. Is noise the only reason for it?

[jpnovak]

Leave it out. The sound difference is minimal.

If you don't like the glue, get some adhesive remover or a can of acetone and wipe it off. Don't rub too hard or it can take paint too.

[Jay H]

Originally posted by Crachian
I'm about to replace mine because I thought there was a difference. Is noise the only reason for it?

My brother yanked his sound pad on his '83 SC (motor was stock) when it crumbled. We both noticed an increase in engine noise. From what I remember, there was more fan noise and you could definitely hear more valve train noise.

He ended up replacing it because it got a bit too much noise over time (grew tiring). With the new pad in place, the engine music is much better.

Just my $.02...

[vinny c]

Just replaced sound pad the other day. Did a partial engine drop, pulled the old one off (original) and placed the new pad, sprayed adhesive and stuck it on. What a difference! With the pad in place it brightens up a normally dark area. Definitely worth the effort.

Vince

[Randy Webb]

I'm happy with the new factory pad. It is light wt. and we should assume that PAG knows what is doing.

The Al pads will reflect heat back onto the engine. It is unclear how important this will be, but it is obviously something to be avoided.

The shiny Al ones will also get dull and show dirt.

[youngkang]

I agree with Jamie, sound difference is minimal and make it easier to adjust CIS.

['78 SC]

Heat is also a valid concern. I suspect few of us spend much time in the back seats, but my kids pointed out there was a lot of heat coming through the bulkhead. For their comfort (and the longevity of the upholstery), I replaced the collapsed and crumbling pad when I had the engine out recently. Much cooler now. The factory style foam pad is probably more effective on heat than on sound.

[bell]

my sound pad was crumbly too.....yanked it.

i've been doing alot of car interiors lately with dynamat.
i've been using dynamat "extreme" and man do i like this stuff, it is 50 times easier to put on and conforms to any bend nicely.
my 911 will be redone with it this winter with it.