Engine bay sound deadening

[estland 3]

HI guys,

 

Can you recommend, what sound deadening to use on outer side of engine bay bulkhead, 

 

I guess for starters it should be fire resistant, so bitumen based insulation should be ruled out?

[estland 3]

My car has always had quite high engine noise on highway. Starting at 3000 rpm. 

 

Is it just my car or is yours the same?

[boldy205 74]

Probably all the same. 

From the factory they had sound deadening on the underside of the bonnet, most if which has Probably deteriorated by now

But nothing I recall on the bulkhead. 

No doubt you can retro fit something from the likes of Carbuilders Solutions etc

[DamirGTI 323]

They're all the same ... under bonnet sound deadening really doesn't do any noise reduction , i've had it for years and removed it recently - no difference what so ever .

 

I'd say it's the low gearing which makes for the most of noise as the motorway cruising speed is always in excess of 3000rmp , even with the long ratio box it's just about 300/400rmp lower which doesn't help either .

 

Next , exhaust , having good quality system/mufflers helps ...

 

Maybe some good quality cabin sound deadening might do the trick .. but that should include wrapping up the entire cabin , floors , firewall , door skins , quarter panels etc. .. body panels "vibrate" creating noise too ...

Something like "Dynamat" insulation or similar , but it's a bit expensive and needs to be bonded onto the metal .. which for a 205 i would think twice about doing it as it tends to be leaky during the rainy days and the last thing you'd want is rotten floor because of the "stick on insulation" holding moisture .

 

I've used in the past K-flex rolls :

 

 http://www.k-flex.com/en/

 

.. there's various thickness , it's flexible rubberized kinda material can even get it with the aluminum reinforced top side , they have glue on the bottom so you can stick the roll/pad on the body panels .

That did reduce the cabin noise to a degree , but i haven't done the entire interior , i did just the floor ..

 

Failing all the above , an good audio system with big bass/woofer , set of speakers and you're favorite music turned up a bit does the job "distracting" from the engine noise .

 

 

Anyhow , it is a bit annoying yes .. myself i also use the 205 as an daily drive and the noise does make me bit sick and tired nowadays .. i'm not as young as i used to be , more quiet is what i would prefer as well .

 

 

D

 

 

Edited April 26, 2021 by DamirGTI

[estland 3]

Thanks Guys for the replies

[davemar 16]

I would have thought the panel on the underside of the bonnet is more to do with heat insulation, rather than sound deadening, to prevent the bonnet getting too hot? It's too flimsy to be of much use acoustically.