Add sound insulationg material under hood?

[sixdogs]

Would you ever add sound deadening material to the underside of a cab tractor hood? A replacement hood I ordered for a Kubota M7040 has "Heat and sound insulating" material that needs to be added. That makes sense with an under hood muffler. But there's also the sound insulating aspect mentioned and I just happen to have a fair amount of expensive self-stick sound insulating material left over from a hot rod build. Kubota added some to the factory build so more is better?

Would you ever add some to the underside of the new hood? No doubt it would be dramatically quieter but should I care? The material I have will never be used and here in front of me is a potential use. Any thoughts?

 

[Aquamoose]

Can’t see why not!

 

[oosik]

As long as it won't interfere with the mechanical operation of anything under the hood - I would definitely go for it. Personally - I've never been bothered by engine sounds but I bet they DO become louder if you have a cabbed tractor.

On second thought - perhaps a word of caution. So you put sound insulating material on the underside of the hood. The engine - etc - will still make the same amount of "noise". Now with the insulating material under the hood - where is the sound going now. Into the tractor cab - - I sure hope not.

On an auto the most efficient place to use sound insulating material is the firewall. It excludes sound from the passenger compartment. I don't think I can ever remember seeing sound insulating material on the underside of a car hood.

Just a random thought........

 

[TractorGuy]

Two things I would consider is if it would touch anything and will the adhesive withstand the heat.

Other than that you won't know unless you try.

I have had vehicles that came with a thin layer of insulation under the hood. Those were always held in place with plastic push type retainers.

 

[JimRB]

My Dodge truck, my VW car, my JD tractor all have sound deadening mats on the hoods and firewalls. The car and truck have mats on the floors, mats around blower motors, mats and blankets everywhere. Mats are designed to absorb noise, not reflect it. I do not have any old cars to look at. My VW is a 2003 and the Dodge is a 2004. Both are diesels. The tractor cabs I have been in have sound absorbing or dampening mats everywhere. One diesel powered delivery truck I rode in one day 30 years ago did not have any sound dampening. Hearing protection was practically required to survive a day in that truck. Noisiest thing I have been in this side of open header cars.

 

[Aquamoose]

On second thought - perhaps a word of caution. So you put sound insulating material on the underside of the hood. The engine - etc - will still make the same amount of "noise". Now with the insulating material under the hood - where is the sound going now. Into the tractor cab - - I sure hope not.

Actually not true, sounds do get absorbed much like sound booths & carpet in homes do.

 

[deserteagle71]

My M7060 came with a cab. When the engine is running it is much quieter inside the cab than if I am standing outside beside it. It's quiet enough that I can easily listen to the radio (I installed the Messick's special) while mowing.

 

[Jchonline]

I would also ensure it doesnt impede air circulation or create excess reflective heat under the hood.

 

[sixdogs]

I'm the OP and here's what I did after thinking about all the posts. The material would deaden sound, no doubt about that but it would also impeded air flow. I think this because I recall the side of the hood of some tractors getting hot in the summer. Perhaps bare metal was some sort of heat sink that engineers needed to keep things under the hood cool?

Anyway, I put insulation in the new hood exactly like they had it in the old hood. No more, no less. And the excess sound deadening and insulating material I keep rolled up in the basement will stay there for another day. Thank you.