I've got a 97 F250 with the 7.3 and I absolutely HATE how loud it is. I bought this truck for it's known reliability, but FML the noise... I did the HPX mod and I did note a slight decrease in clatter at idle, but not enough to make a big difference (esp. while driving at lower speeds). Are there any other methods to quiet the engine noise? Is there a way to sound proof the cab enough to deaden the sound? I've watched a couple of videos of people trying to dynamat the cab with mixed results. Does anyone have any experience in this?

V10 swap??  

The best sound deadening I've ever seen was thin sheets of lead on the firewall, hood, and cab floor.

But honestly you bought a road legal tractor it's never going to be modern diesel quiet. Just the nature of the beast.

Either adapt and become used to the noise or sell it for something that runs def.

You're fighting an uphill battle. But a fight worth having if it bothers you that much. I'm weird about sounds like that too. But, this will be a hell of a project, and you'll need to be very thorough with each step. And, honestly will never be as quiet as a modern diesel. Just know that going in.

A lot of the sound you're hearing is coming through the hood and the windshield. Step 1 is an acoustic windshield. I'm not a glass guy, but I think you're stuck with just upgrading the windshield. I don't think they make aftermarket acoustic glass for the doors.  If you find some, let me know.

That'll prob be the largest single change. After that you can put a liner under the hood that is cotton carpeting jute that is foil faced on both sides. There's a few products out there on Amazon. I think one is an American company. But I forget the name. They also sell a high temp spray adhesive and a foil tape to adhere it to the underside of the hood, and protect the insulation from the elements.

After that is the fun part. Removing interior panels and carpet. Then, Vacuuming/scrubbing/steaming  the metal floor since it'll have 25 years of sand and other crap that was spilled and then dried. Then dynamat the floor, interior and exterior door skins, and maybe even the roof. And, hope all your panels fit back together properly.

Oh, and your weatherstripping is also 25 years old. There's a good chance it has shrunk/dried out some, and is letting in engine/road noise. Rejuvenating it once it has lost its original dimensions is nearly impossible, so replace that too.

Good luck!

You could also swap in a common rail 5.9 cummins... But that's not for the faint of heart.

On my ‘01 7.3l just using a diesel additive made a substantial difference.

It’s an OBS, just rock it. The neighbor has over 400,000 on his. Let’s see some pics.

Edit: sell it to me cheap if you don’t want it.
      My 01 is quieter that an OBS but it’s still too loud to order at         drive through while running.

It's older and diesel. It'll have a clatter.


You can use sound deadener on the cab which will help some for everything. You don't need 100% coverage but you do want to add a significant amount of mass to the panels. Lie the doors, roof, walls and floor with sound deadener. Then your next biggest will be the windshield. It's basically a giant speaker for sound outside the vehicle. Likely there is not an acoustic windshield available for your rig.

Try sound deadener first and see what happens. Or just get used to it.

Summit Racing has a Dynamat knock-off kit Here.  Use it on the underside of the hood, and inside the cab on the firewall, and floors.  It will somewhat deaden the sound and resonance from the rattling box of rocks in the engine bay.

The only effective way will require a monthly payment.

This, basically.

There can be improvements, but it will take large amounts of effort, money, and disassembly of the truck. In the end, it's probably not worth the effort.

Many years ago I had a 2001 Cadi DTS that I drove the hell out of. It was a quite car for the most part when the tires were new and road smooth. The second the tires got worn down they got pretty loud.

I used Dynamat and sound foam in every place I could-which was underneath the standard sound deadening stuff. I even did the doors. Did not help much for that sound.  

I suspect it depends on the type of sound and were its coming in from if Dynamat and foam will work.  You can also put a coating on the outside of the cab/engine bay side.

It's like straight pipes on a hemi charger. Enjoy it while you can. Won't be long before the whine of an electric car is all you'll hear.

I love driving my ole 7.3l, 97 and 92 down through the college area in the summer. All those cute colored haired things just stare.

Do you understand why and where you use foam vs a mass adder?



Kilmat is one of the cheaper options right now. Dynamat is insanely priced. Been using kilmat for quite a while now. Used it to sound deaden a vacuum pump cabinet a couple months back. Can now stand next to it and have a conversation at normal levels vs uncomfortably loud before.

OP, you need to visit a car Audio forum. It won’t be easy or cheap. You need to employ several different technologies and strategies.

The very basics?  Dynamat (or similar) and MLV (mass loaded vinyl).

Dynamat is relatively thin and sticky. Once you get every piece of interior out if your cab you like all of it you can. Some people say you don’t need to cover every square inch. I disagree.

Then you need a decoupler. You really don’t want your MLV touching the Dynamat directly if I can be helped.

Then it’s on to the MLV. It’s heavy and dense and a bitch to instal. You’ll have to use great double sided tape, or glue to adhere it. And when you’re done good luck getting your carpet, door panels, dash, and everything else back on. They won’t line up/fit together/line up with screw holes because of all of the thick material you’ve added.

But if you can accomplish it, correctly, you’ll be doing…..pretty good.

I say that because you’ve still got approximately 35% of you vehicle cab comprised of glass, which is a terrible sound deadener.

OP , I hate to tell you this, but that noisy chatter is your worn out injectors . Replace them along with your cups, glow plugs and wiring harness and that 7.3 will run for another 300K

Injectors and glow plugs were replaced at 215k, so I know I am good there.

Here's a pic of said pain in my ass -



I have a box of kilmat and I have read up on another guy that tried to quieten his 7.3, to no avail. So, I am looking to fix it up and trade it for something else. Not looking for another 6.7, as I can't justify the cost of one (even used is retarded). I sold my 2014 F350 with 109k for $35k back in April of 2021 and I swear I'd give anything to go back in time and get it back, but it got us into our 2021 MB Sprinter so I at least have that going for me. I appreciate everyone's input, it's awesome and it's very much appreciated!