So recently in the past few months I get this hard buzzing/crackling sound when under load around 2,000-2,500 rpms on the drivers side. This can be loaded with a trailer or just climbing up a grade unloaded. I've been too busy/lazy to investigate and have heard the catalytic converters were possibly bad during my model year (08 built in 07). Anyone else encounter this? It almost sounds like the exhaust is blowing through something broken but has only really appeared at that rpm range. Push the go pedal for more rpms and it goes away. I really don't think it's a rusted clamp as I already found a few of those and it doesn't seem like heat shield but when I'm not being lazy I'll check both. I had an exhaust manifold replace on that side an wonder if the tech beat the snot out of the exhaust to remove it and damaged the cat?

 

Mine has done the same thing since 2 days after i bought it and has progressively gotten worse. I havent really checked it out either.

 

There is a bulletin out there for this issue. It covers gas powered 08-10 SD's. The # is TSB 11-1-3. I believe that there is an extended coverage on these from Ford for 11 years or 120,000 miles. I ran the OASIS on my 2009, and it came up with a notation of that special coverage. Mine were changed at 39k miles for a rattling noise. Hope this helps!

 

You know I think that I got a letter from when I had my manifold replaced about that. I'll be heading to the dealer in a few weeks to get this checked out if it is covered.

 

could also be a cracked/broken spot weld on a heat shield on the exhaust to..

that would also create a harmonic vibration type ring noise...

 

My cats were replaced under warranty at about 80k, or at least the Oasis report said they were.

 

I just fixed this exact problem on my 2004.
Buzzing at 2000 RPM. It was the muffler.
Internal baffling or something that was rusted or broken.
It sounded like a kazoo at 2000 rpms to about 2400 rpms.
Externally the factory exhaust system still looked sound and had no holes but, the resonance was something internal to the muffler.

This was confirmed when I had the muffler off and on the ground. It sounded like a can full of rocks when I shook it.

My truck is a 2004, but only has 40,000 miles on it.
Sure sounds like the same problem.

A new exhaust fixed it on mine.
Good luck in your hunt.

 

I've had this problem on other vehicles and it could be a possibility but it just sounds like it's under or a little forward of my door which I believe is where the catalytic converter is....and the muffler is much further back. But still work a check.
Thanks

 

mine is also like right underneath the floorboard. drivers side only. like a buzzing from a slight rattle. sometimes even sounds like someone is throwing sand through my cat converters

 

Yes, I can say that is a good representation of the sound. Unfortunately I've only had enough time in the day to come home, sleep, ten get up and work, repeat cycle..... So I'll be chasing this at other times.

 

My Cat clogged at approx 30K miles and had to me removed.
See my thread about power loss and pinging.

https://www.ford-trucks.com/forums/9...-2004-v10.html

In my case (2004 F350) it made no noises, just caused my truck to have no power and ping under load.
I removed the Cat and the truck went back to normal.
Approx a year & 1/2 & 10,000 miles later the muffler started buzzing like a kazoo at 2000 RPMs as described.
I changed the exhaust system, now all is perfect again.
No kazoo sounds, full power (actually even better than before).

Hope this helps.
cheers
jimmy

 

My 2006 had this problem, I had rocks stuck up in the heatshield for the left cat. It made a vibration/rattle sound like an exhaust pipe resting on the frame. Very annoying, got them cleaned out of the heat shield and went away. Just my $.02

 

My dad's 02 v10 has had that buzzing noise since I can remember, only in the lower rmp's when engine is in higher gears under more load. I was wondering if it could be preigintion. What test fuel does ford recommend? We've always run regular. I thought maybe it was the cats rattling.