PLEASE HELP!!!Intermittant rattle noise while driving....not heat shield.

[05ExplrAWD]

Newbie to the forums, hoping you guys can help me out....
I have a 05 Explorer Sport 4.0 4x4 approx. 58,000 miles and I'm running out of troubleshotting ideas...

I just went on a short trip this weekend (approximately 50 miles each way) on the highway(approx. 65/75mph) and when I got off at the exit, stopped at a signal, then proceeded to drive...I have a loud rattling noise coming from what sounds like the LR wheel area.
-It definitely doesn't sound like any wheel bearing noise (expierenced it before w/ this truck).
-I checked the heat shields, tapped on the exhaust pipes, cats, muffler..no noise.
-Lug nuts are tight, backing plate for the brakes aren't contacting anything.

There are no "obvious" signs...

The noise is only present from about 20mph and higher(while accelling/maintaining speed) it gets louder with speed increase, but is harder to hear w/ the windows open and road noise. and sometimes has started after hitting a bump while driving.
It goes away when coming to a stop around 10/15mph and startes again back at around 20mph.
It's very annoying and a little upsetting when I have a good looking/well-maintained truck making loud rattling noises. PLEASE HELP!!!

 

[HiImBrian]

Look at this:

http://www.explorerforum.com/forums/showthread.php?t=386061

I had the same thing that I thought was a rear wheel. Turns out this was it

 

[05ExplrAWD]

Thanks for the info...I'll have to look at that and see if I missed what might have been right in front of me....

 

[05ExplrAWD]

....Unfortunately after a quick look underneath, that a completely different style driveshaft than my 05' has.

Back to the drawing board...

 

[Bobmbx]

It sounds like something may be flapping in the breeze. Check all your trim pieces and the wheel well inserts (mud flaps, etc.) for looseness. Oh yeah...check your license plate holder. Mine was loose on the bottom and only made noise when moving at highway speeds.

You ever see someone driving and a trim piece is flying? Then when you stop, it goes back to its normal place? You may have something like that.

 

[05ExplrAWD]

Thank you, but already checked all things like that...

It definately sounds like something metallic "flopping" around, almost like an exhaust shield rattle, but its not. They now all have claps on them.
Plus, in my experience I've been able to duplicate those with a slight load on the engine while in Drive or a soft "brake torque".

This one has me stumped...I'm really dreading if I have to visit the stealership.

 

[Jfretton]

Maybe a bad cat. Had mine replaced in my 04 after the internals blew apart. Having the same issue as you but mine also happens at idle. Need to get it checked.

 

[ronwc]

Cat

One of your cats is bad.

 

[apanello]

Rev it up in park? No rattle - not the cat