I'm going to run a few things at you to consider. While you have it gutted-I would replace the rear Expansion valve on the AC, and the relay for the blower motor. Make sure your rear blend door actuators work. I'd check my backup speaker and check out you rear washer hose. Pretty much anything I could make new in the back, I would.

As to sound proofing/dampening-making the damn thing quieter...Hush Mat and all those butyl rubber products dampen noise. If you look inside the front passenger door, you will see a welded piece of metal on the inside of the outer door panel. That was to dampen vibrations reverberations, metal buckling from the stereo system. The butyl rubber only goes so far if you are trying to soundproof (make it quieter inside). Sound dampening is only part of soundproofing. Turn on the radio, put a piece of butyl rubber over a speaker (don't compress the speaker components-just use as a barrier and see if you still here it,? Muffled yes-gone no. That cheap crap chipped foam is the best insulator ford stuck in the door and they were too cheap to put it anywhere else. Basically you need a thicker air cell material to block or I should say absorb sound--same thing they do at recording studios and hearing aid places. The butyl on the roof will make it quieter going through a carwash. Still need some absorbent barrier to kill more of the sound. I didn't read all the way through your post so I may say things you have already done or plan on doing. Everywhere you practically can, I would place butyl on the back of all the crappy plastic trim in there. Foam work well as long as you don't smash it flat-then it's useless. I'd line the buytl on the roof with a sound absorber-foam or even insulation for that matter. You need thickness with open air to absorb the energy of the sound waves. If you want to kill wind noise on your doors, weatherstrip the actual door itself. Here is what I used: https://www.homedepot.com/p/M-D-Buil...1033/100175299 (19/32 in. x 10 ft. EPDM Cellular Rubber Auto and Marine Weatherstrip). If you really want to go for it, you can spray sound deadener on the chassis. Not my cup of tea but what the heck. Putting the headliner back up-"May the Force be with you!"

Anyway you're probably way ahead of the game. I'm just saying doing the butyl rubber alone will leave you disappointed-or at least for me. I hope you really nail this sucker. I will need a new project when I retire. Good luck!

 

I wouldn't mess with the rear A/C if it's working properly, as it's a decent undertaking, unless you are in the HVAC field. I did replace most of my stuff back there, but that's been my trade, even then I ran into some issues with a few parts leaking once under a vacuum. A good tip would be to seal the headliner duct unit. I used Lexel in the caulk gun tube, and added a generous bead all around, then smeared it with my finger. This made a huge difference in airflow as the duct unit was no longer sealed to the headliner. The up duct that inserts to the headliner may need the foam gasket adjusted, as they slide down causing air leaks. Lastly the foam on the rear dampers for high/low. and hot/cold likes to come off and jamb the door movement. These can be removed and re-glued after you open up the 2 piece blower/coil housing.

 

I used exclusively the Kilmat for the same cost vs effectiveness and reviews. My research deduced it’s better than most of the others and not outperformed by even the Dyno brand. I didn’t go to the same extent that you are and am very curious what kind of decibel readings you get. My passenger area (front and second row) floor has not been done yet but nearly every square inch inside all six doors (outer skin inside and inner panel outside facing the panels) has two layers of the Kilmat including above the headliner. The passenger area floor will be done next week when I have all new leather upholstery and new cut pile carpet installed. Currently the decibel reading using an iPhone at 75 mph and new Michelin LTX-MS tires is under 70 db. At idle stopped its 55 db. Before any Kilmat was applied and with Cooper all terrain tires, it was over 80db at even 45 mph. I’ll be checking again after the new upholstery, carpet and two layers of Kilmat on the floor.
So far, the entire interior required 11 boxes of Kilmat. Each box = 36 sq ft = 16.8 lbs. ~184 lbs added.

 

Oh my.......I'll take replacing a rear expansion valve and a blower relay over all that any day. Both of those parts predictably fail. However, taking things apart is obviously not a deterrent for you so more power to you brother!

 

My rear system actually worked perfect, still had original parts, but as one can tell, I've been on a frenzy to get things replaced before they go extinct. That headliner is from the V10 I briefly owned, and the blower box is a spare from the junkyard. The V10, and my white 7.3 had the same issue with that foam coming unglued and blocking the door, and airflow. I need to take my headliner down again in the white 7.3 to seal that spider duct unit.

 

Sorry for the delay, I hurt my back several times started running short on time before I had to make another 1k mile trip plus all of the delays for local travel and getting the front end repaired. I'm 99% done now, just have a couple of oopsies to fix which I'll get to. Also found some tips, tricks and don't you dares to share.

Back half with Kilmat and Siless before I decided that the best route was to work from the top down. DO THE ROOF FIRST and work your way down - this will save a pair of pants from being destroyed by the butyl that gets squeezed out by your knees on the floor. Literally every square inch of bare metal got the Kilmat followed by the foam.


Spare tire area. Note that I got the floor, outer skin, outside of the inner skin (can't see) and the inside of the inner skin. The only thing that I didn't do, not entirely sure that it's needed at this point (you'll see why at the end), is I only laid down a single layer of Kilmat and foam across the wheel wells.


Where the headliner edges met the window area I made sure to add some foam just in case it rubbed on the metal. It's the area with the gold bolts poking through. Where the wire loom comes down the c-pillar behind the middle door, I drastically underestimated the amount of room that was there. You can see where I but pieces to go under the loom without touching the fasteners, but in reality you'll probably never be touching those wires and you could just foam right over the top of it for a more complete coverage.


Hera again, I didn't work from the top down and you can't really see it in the pictures but I tore up the foam a bit with the toes of my boots. Probably didn't make a difference, but it would have made me feel a lot better to go top down. I was considering adding more foam to the roof - don't. There is not enough room for more than a single layer of Kilmat and foam.




You can see I tried my best to keep all of the holes open that I figured were there for a reason. I didn't take a picture of it, but all of those cavities between the skins got filled in with more foam. To make all of these cuts, I would highly recommend not using a box cutter. Just go buy a $1 exacto knife in the arts and crafts section of any store with a couple of extra blades. It is WAY easier. I had an exacto but I broke the blade and didn't have any replacements so I had to go back to a box cutter. Even with a new blade, there's no comparison to how much better the little pen-like knives are.


For all of the ends of the wire looms I tried to make sure that I didn't place any foam that would inhibit movement for things like the dome lights. Take this to heart.... When you try to fish the wires after getting the headliner put in it makes a big difference.




Here you can see the cavities starting to get filled in over the rear hatch.






I feel like this picture shows what you should be aiming for. Anywhere near the driver's seat you should go for 100% foam coverage just because it's closest to your ears. I wish I had taken the time to cut 1" strips from the fronts and backs of the braces. Would it have made a difference? Dunno, but I would have felt better.
*Special note for the seat belt sliders. You can 100% get foam into the dip, but you need to actually slide it to make sure that you don't bind it up. This quieted mine down immensely but I had to cut some of the foam back off to keep it from being too binding.
On the area by the windshield I jammed a boat load of foam into the cavity. I know wind noise can be brutal when the windshield glue starts to go so I figured this was good prevention.


You can see that I did not cover any of the cab mounting bolts at all - don't do it.... If you ever have to pop the body off for some reason, you don't want a mechanic to rip out all of your hard work just to get to some bolts when it's 100% avoidable.


I went 100% as far up the firewall as humanly possible with everything. Kilmat all the way up, foam all the way up, MLV all the way up. Besides the cavities in the roof and walls, I used a lot of cutoffs from everything around here just to make sure I got as much as I could.


I did not get a picture of the final product, but this is the MLV. If you have never worked with it, please note that it is HEAVY. 1 pound per square foot sounds like nothing, but when it comes in a 4'x25' roll things get.....tough. I mention this because the Marine Corps destroyed my back and this caused me a really bad week of recovery fighting it around. Here's what I think the best practice with with MLV is.
For the rear, I cut the section to go front to rear. I figured that dragging stuff out of the cargo area would eventually shift it to the rear and cause issues, but if you go front to back then you can lock it in place with the seat.
For the middle seats I laid it down side to side because that made the most sense.
For the front seats, I went from front to back. This is essential so that you can lay it up the firewall and make relief cuts without having to worry about shifting something on the other side of the vehicle. I did the drivers then passengers side before filling in with the last piece over the trans tunnel.
It is also worth noting that this is arguably the most important part of the soundproofing. MLV really is that effective. Just remember that you cannot just lay it down over the bare metal or the Kilmat, it needs an isolation layer, hence the foam.


Property wise, the closed cell foam is an amazing insulator. The temps dropped hard and even in Texas it was in the 30s while I was doing this. When laying down the Kilmat I was bundled up good. When I laid down the foam I was down to a t-shirt and happy. The foam is an amazing insulator and reflector of heat and cold. Driving it down the road the heater and AC were working WAY less.

 

What a great job!
I didn’t use the closed cell foam or MLV. I’m curious to see what your decibel levels will be compared. With only the Kilmat, 2 layers everywhere, and new Michelin tires, I’m seeing 67-68db using the iPhone app. I consider this exceptional considering I started with 80db.

Apologies if I already asked but are you planning to do under the hood? I’m still looking for a good solution better than the fiberglass hood pad. The only product I have found specifically for under hood applications is Dynamat.

 

If you have the overhead DVD console thingy, don't foam it. With Kilmat and Siless on the roof, there is zero extra room. Turns out it's not needed at all because the bracket below will be mashed up against the foam on the roof. Foam removal sucks...


This is the foam tape I mentioned at the beginning. It's about half as thick as the Siless and extremely flexible so it works great for wrapping cables or wherever there is just very little clearance.


On the bottom side of the center console, I did a test fit and jiggled things around only to find that the power cable for the 12V socket makes contact. At least it used to... Wrapped the portions that made contact and then hit the console itself. Worked like a charm.



Don't be an idiot like me. I forgot what order I pulled things out and put in the headliner before I put in the DVD frame. I fixed it here, but I tried my best to fight it in by dropping the headliner and reaching, it's just not possible. Install the stupid bracket prior to the headliner.


*I did not take a picture of this part, but I posted questions about the depth of the AC channel in the headliner. Well, after some searching I found out what my problem was - I didn't have the full AC enclosure in my headliner. I don't know if a previous owner cut it out or what, but I did some searching around and I found a perfectly good headliner, in the right color WITH THE SAME overhead accessories I did. I seriously doubt I'll ever have that kind of luck again especially since this came from a junk yard. No it wasn't perfect, but it didn't have any major blemishes or mold. Couldn't believe it.

Screw Ford's engineers. On the middle seats you have to have an 18mm wrench to get some of the bolts out, but the ones that are on the rear and closest to the centerline of the vehicle are especially insidious. You have to have a box wrench and make micro turns. The solution is simple, I was just too tired to deal with it at this point. The best solution is to get a grinder, cut off wheel, dremel tool, a hacksaw if you have to, but just notch the seat frame over the bolt hole so you can put a socket wrench on it. Seriously, this pissed me off more than anything else on this project. With the seats out you can get a grinder in there no problem.


This was a mistake to learn from. The factory foam on the upper AC vent in the rear was highly worn and useless. I wanted to create a good seal on the tube and keep it from rattling so I put down 2 strips of foam, but you can ONLY PLACE ONE STRIP all the way around. I tried, it's just too tight. I also foam lined the exit of the tube at the headliner for zero rattles.


Here's the upper vent entrance that someone tried to rattle proof with duct tape....that's why I foamed the AC exit.


This is the only picture I took of the doors because I ran out of time. I finished this at 3AM, took a shower, got in the truck and drove 450 miles. I did the same as everything else in the truck - I put down a layer of Kilmat across the entire outer door skin as well as the inside of the inner door skin. Then I added a layer of foam over all of the Kilmat on both sides. There was very little additional soundproofing I needed to do, but I did use the foam tape to wrap the portions of the door lock. It is a very long metal rod that rattles pretty bad so I foamed it around the rod holders and it worked great, just make sure you leave enough room that it can fully actuate without hitting the foam. I also used the foam tap on the door trim at the top where the panel rests on the metal door frame. This did cause a very very tight fit, but it's doable and it has a ZERO chance of ever rattling. I did not add an MLV to these doors just due to time, but I might. There is a LOT of room inside the doors for more material. I'll wait a few months until things warm up just to see how well the MLV and glue hold up in the rear doors. So far they have about 1500 miles on them and they are holding fine.

 

So all in all, I laid down 1 layer of Kilmat across the entire interior to include the outer vehicle skin, outside of the interior shell and inside of the interior shell. I laid foam down over every bit of Kilmat and then stuffed the negative spaces with as much as I could. I laid down MLV across the entire floor of the vehicle. I didn't say it before, but the added thickness of the floor (kept the factory carpet pad) kept the carpet from going back perfectly. I had to make a couple of relief cuts near the door sills so that I could get the door sill trim through the carpet. Everything is hidden, you can't tell. All material was applied from the outer skin of the rear doors as far up the firewall as humanly possible without removing the dash.

Grand total usage:
Kilmat - 11 boxes of 18sqft each for a total of 198sqft
Siless foam - 7 rolls for a total of 252sqft
Soundsulate 1/8" 1lb MLV - one 4'x25' roll for 100sqft.
Soundshield WRAPIT - 1 can that had 2 rolls
1 can of brake cleaner
25% of a bottle of 91% isopropyl alcohol
1 roll of paper towels and maybe 4 shop rags
I drastically overestimated the needed cleaning/prep supplies...

End results:
My test run showed 80db average with 86db peaks in one direction and 82db with 86db peaks in the other direction. I guess the road was rougher eastbound than west. The truck now averages 68db with 70db peaks. Holy **** snacks what a difference! Decibels are measured logarithmically so a drop of 10db reflects a HALVING of perceived total volume. I DROPPED 14DB. I cannot fully explain in a way that would represent what a drop this is than just giving you the numbers. It's not quite a Bentley now, but it's pretty close. I used to have to yell to get to the kids in the 3rd row, but now I can do it with very soft volume. Not that it matters, but idle is down to 58db from 63db.

It should be noted that if you keep the factory sound deadeners in place, including the factory butyl and under carpet padding, you can ONLY add a single layer of each material across the entire vehicle. The roof cannot accept more than 1 layer of Kilmat and Siless, the floor cannot accept more than 1 layer of KIlmat, Siless and MLV. The doors can still accept more material as well as the wall cavities in the 3rd row. Instead of filling it up, I'm thinking about adding a very small bass box to the driver's side 3rd row wall.

The final verdict is - I wish I had done this sooner. The difference is huge and amazing. It might be that I'm more sensitive to the change because of how bad my tinnitus is, but the numbers speak for themselves.

Side note, I did not know until after I ordered the stuff, but Kilmat and Siless are both manufactured in Russia. I would have avoided them if I knew ahead of time, but the products themselves are solid and recommendable.

I'll answer whatever questions you guys about this because you should ALL be doing this!

 

I haven't had a chance to dig into the options for this yet, but I'll be diving into that after Thanksgiving.

 

Well done and congratulations!
Your sound pressure numbers parallel mine.

Great work!!

 

Couple of things I was thinking about.

When putting the 3rd row wall trim back on, make sure you have some foam between it and the window on both sides. This is a new source of rattles.Driver's side middle seat developed a new rattle, turns out its the black plastic trim around the bottom and under the seat. All you have to do is put foam on the metal frame rails before putting the plastic back on. Also make sure you foam or foam tape around the metal rod for the seat release pull as it shakes hard.

Might be out of comfort range to think about, but this is on the inside of the truck, not the outside. When i started getting my arms in-between the body panels, especially in the doors, I got cut up a lot. Run a piece of sandpaper around the edges to deburr and save yourself on the cuts.

Inside the doors, foam tape the door lock mechanism on both side of the full open/lock position. I tried to see if I could just foam tape under the rod by the anchor point in the middle, but it just didn't work and applied enough pressure that the door lock wasn't working 100% and I figured it would burn up the motor.

Doesn't show in the pics, but I pulled off all the speakers and made sure there was foam between the speaker housing and the metal.

Save all of your cut offs because they work perfect for all of the doors and cavities of the roof, pillars, doors and dash.

Put a lamp on the inside of the truck while you do this...it only makes sense to see.

I wish I would have found mine (lost in the move) but shampooing or steaming the carpet was high on my list before putting everything back together. I got it really good with a vacuum but it's definitely not the same.

Here's a big one. When you are dismantling everything I thought of 2 options. Some things I put a piece of tape on and stuck the nuts/bolts to it. Other things I'd use a tacklebox. If I ever had to do this again I would get the large flat lure boxes with movable dividers and just rip off a tiny sheet of paper with a label that say SUNVISOR. I lost 3 of those things...found some replacements, still pissed me off because it's avoidable.

With the seats out I put on some YouTube and just zoned out while rubbing in leather conditioner. Way easier out of the truck plus you can let them dry so you don't get wet butt syndrome...

Finishing touch is definitely the smell. If you have never heard of it, look up the Chemical Guys. They sell on Amazon and elsewhere but the new car and leather smells are pretty good and long lasting.

If you have kids or someone that is willing to help you out then I would say while the panels are all out that you should give them a hard scrub with whatever you have available. I ran out of time to do it so now whatever cleaner I use will have it's smell stay in the truck for a while.

 

VERY well done! When I did my swap, I had most of the interior out of mine and did the floor with the kilmat material (not that brand). I bought enough to do the entirety of the inside and your thread has inspired me to maybe take it a bit further. Running the Cummins with a straight pipe creates a fairly loud interior, even with the windows up. I have a fair amount of work to do on door bottoms and rocker panels, but this update will follow. Thanks for the detailed information and pictures!

 

I'm definitely going to do more when I get the time. I figure the next step after Thanksgiving is to figure out what all I can do to the hood. After that I'll see about some sort of a spray on for the bottom of the cab. Eventually I'm going to have to replace the rear main seal because it leaks like a sieve...when that happens I'll hit the engine side of the firewall pretty hard with something as well. I have also started noticing more and more wind noise and finally figured it out. The rubber is in great condition, but the seals don't hold onto the metal very well and sag creating an pocket for wind to whip through. I tried to realign it but the weatherstripping wasn't cut to the right length so if I install it tightly like it's supposed to I'll be about 2 inches short all the way around. I'll figure something out...will probably just find a foot of it to fill the gaps after I reinstall it properly. ​​​​​​​I should have mentioned this earlier as well but when I was installing the trim panels that overlap each other, I placed foam on the hidden side to keep anything from rattling or rubbing and that has worked out pretty dang well.

 

This is very intriguing! I LOVE my Excursion and never plan on getting rid of it, 293k on my 6.0 now, hoping for 400k and then we will see if i want to just replace with a new 6.0 and trans?? My issue, is mine is a 2WD.

May I ask how much total approximately did it cost for materials? How long did it take(guesstimate)? Id REALLY like to do this! I love my audio too, so it has to help with rattles and such. Mine also has the rear DVD system so good to know. Is the foam necessary or would the Killamat be ok by itself? It looks as though both the foam and Killamat(if thats the right product-as i can't see it when typing on my phone)? You lined every panel on the inside? Or some of them both sides?