catalytic converter's have been an issue for some.....would be covered under emissions warranty for 7 years 70k miles, or something like that..a long time.
Need to have dealer replace them, if that's the problem, for warranty coverage.

 

I can almost guarantee your timing chain is coming apart. Your description is exactly what mine sounded like. It's a common problem - at least on the 6's. Several days and several attempts, and she'll be as good as new - if you go to the dealer I had mine fixed at. Got the usual explanation for the delays and problems - parts on back order.

 

I just had all three timing chains and the tensioners replaced to fix a P0008 trouble code and the engine sure is a lot quieter.
'05 V6 60,000 miles.

 

If you don't mind me asking, how much did that replacement cost you?

 

Could be the transfer case. Had the rattle then chatter of the stretching chain on hard acceleration.

 

is a rwd not a awd so no transfer case...unless it really is an awd then I'm with you..tc suspect.

 

Thanks guys, i appreciate your help so far. Yes, it is a RWD so no transfer case. Hopefully, its not the timing chain. The sound is identical to a heat sheild on my 07 ford f150 that just had to be replaced. if it was the timing chain, wouldn't there be codes popping up?

 

There may also be a heat shield on the cat converter.
That noise would be much more toward the front. Like under the front seat.
It could also be that the cat converter is failing internally and when they do that, they often rattle.

Texas Jim

 

Okay....I am going to take a run at this.....I had a rattling problem on my awd 07.....sounded like a heat shield rattle, same as yours.
Took it in to the dealer and they heard the rattle (which is amazing) on the first try but couldn't find out what it was.
So I took it home and jacked it up at the back to make the muffler system available and commenced beating on said system with a rubber mallet.....aha! The rattle! But were is it?
You may not believe this.......the two mufflers (resonators??) at the back are attached to the body with rubber biscuits. There is a hard attachment on both the frame and the muffler that is like a long square U....one end of this U is welded to either the frame or the muffler...as the case may be. Now the rubber biscuit slips over the open end of the U's to make a solid but moveable connection. Over the end of the open U is a washer and what I am going to call a tinnerman nut. (It has a flared serrated hole that will allow it to slide one way and lock the other). This washer and nut were just ever so loose and rattling under acceleration. I took a deep socket large enough (probably 1/2 or 9/16) to fit over the open end of the U and gently tapped it up tight and...... Voila!! no more rattle
I hope that this is your problem as well and not timing chains or anything more expensive! Certainly worth a look.

 

that would be awesome, definately. sounds like the easiest repair. i will be getting under her:helpless:and take a look. i will start at the back and go to the front, if not, it's time for an expensive trip to the dealer. But then again, if I keep my foot out of it, I will not only not here the rattling, but may save some gas money. I appreciate it guys, definately once again. I will post my findings as I find them.:thepan:

 

If you can't figure out what I was trying to explain let me know and I will go out and take some pictures.

 

The exhaust system seems capable of a lot of evils.
The wimpy little cross brace about half way back can, and will, get bent if anything touches it; then it bangs on the pipes. There are big heat shields surrounding the exhaust manifolds - mine ring like a bell when I tap on the pipes, but I can't hear them while driving. The "bricks" in the cats can braeak up and jingle - usually noticeable when revving the motor).
The washer thing is a new one we can add to the list.
But, still 10 times better than timing chain issues.

DG