I'm starting this thread to try to put together information in one place of how to reduce noise in the cab/engine bay of our trucks (soundproofing). While the sound of a diesel is something that most of us like, there's a point where most would like to roll the windows up and have a normal conversation or listen to the radio without it sounding there's a freight train is in the back seat or under the hood. The 7.3 is a noisy beast, but can it be tamed a bit? (I hope)
Any information is appreciated. I don't want this to turn into a product A is better than product B argument, so try to stick with facts regarding DB (decibel) reduction. While I'm not a scientist on this subject, if someone has credentials in this area please state them. Any and all ideas are welcome. I don't have a DB meter so I can't post any actual numbers to quantify my results.
I started by using sound reducing material. I used two 37.5 sq. ft. rolls of this
under the carpet. I'm not convinced that it made a really huge difference overall, though I'm sure it helped. I applied it "triple thickness" in spots on the floorboard especially around the transmission tunnel and toward the firewall. The interior on these trucks is very easy to remove. You can easily have the seats out in 30 minutes and I'm slow. The carpet Ford uses has very good insulation, and is of much better quality compared to the Dodge I previously owned.
Next, I used this material
. This is where I noticed the biggest difference in sound reduction. While I had the interior out of the truck I had to drive it somewhere so I reinstalled the drivers seat. I couldn't believe the amount of road noise that the truck's interior absorbs. It was like riding in a huge 55 gallon drum. I had to take my wife with me so she laid on the floor (very short trip). She commented on how much noise was coming from the rear wall of the cab, mainly through the cab vents on the back wall. So, I lined it with the Noico Liner, then put some of the Mybecca acoustic soundproofing foam over the vents. Being made of foam rubber, air can still pass through. This really helped quiet things down a lot. I also stuffed some of the Mybecca acoustic foam up under the dash around the steering column and behind the glove box. This made a slightly noticeable difference. I'm looking for the part number for a panel that Ford made for the Excursion. It was a flat plastic panel that closed the opening above your feet and pedals. It has a slot for the brake pedal. They were not available for manual transmissions (clutch pedal arm) but I did modify one once for a 6 speed truck by cutting the slot into it. When I find the part number for it I'll post it.
I have installed two mufflers back to back. While this did make the truck somewhat quieter, it doesn't really sound "that quiet" considering the expense and trouble I went to with doing this. There is still the distinct turbo whistle, which I like (I have a Wicked Wheel 2). I think much of the interior engine noise emanates from the engine bay. I've read an article where a company makes a sound deadening mat kit for the Cummins engine that had great results. It's very expensive, but lowers the sound levels from 85db which is equivalent to heavy traffic noise, to a claimed 60db which is what normal speech sounds like. Oddly, covering the oil pan made the most difference (10db). That's a huge improvement from a place that I wouldn't have thought of. The company doesn't offer a kit for the Powerstroke, only the Cummins. The owner drives an 2009 Cummins, however, I have to say that the Cummins is an inherently easier engine to cover due to its design.
My turbo tubes have the wrap still on them, however, I may consider adding some. Has anyone done this?
I haven't done the doors yet, that's next. There was a thread five years ago where a member stated that he had good results from lining the doors. I'll give it a try soon and post my results, hopefully before the weather turns terribly cold.
Well, that's it for now guys. Any and all comments are welcome.
Any information is appreciated. I don't want this to turn into a product A is better than product B argument, so try to stick with facts regarding DB (decibel) reduction. While I'm not a scientist on this subject, if someone has credentials in this area please state them. Any and all ideas are welcome. I don't have a DB meter so I can't post any actual numbers to quantify my results.
I started by using sound reducing material. I used two 37.5 sq. ft. rolls of this
Next, I used this material
I have installed two mufflers back to back. While this did make the truck somewhat quieter, it doesn't really sound "that quiet" considering the expense and trouble I went to with doing this. There is still the distinct turbo whistle, which I like (I have a Wicked Wheel 2). I think much of the interior engine noise emanates from the engine bay. I've read an article where a company makes a sound deadening mat kit for the Cummins engine that had great results. It's very expensive, but lowers the sound levels from 85db which is equivalent to heavy traffic noise, to a claimed 60db which is what normal speech sounds like. Oddly, covering the oil pan made the most difference (10db). That's a huge improvement from a place that I wouldn't have thought of. The company doesn't offer a kit for the Powerstroke, only the Cummins. The owner drives an 2009 Cummins, however, I have to say that the Cummins is an inherently easier engine to cover due to its design.
My turbo tubes have the wrap still on them, however, I may consider adding some. Has anyone done this?
I haven't done the doors yet, that's next. There was a thread five years ago where a member stated that he had good results from lining the doors. I'll give it a try soon and post my results, hopefully before the weather turns terribly cold.
Well, that's it for now guys. Any and all comments are welcome.
