Whining noise at high RPMs

[btmcbride]

Hey folkes I call upon your aid once again....

So heres the deal, my explorer is making a high pitched whining noise at high RPMs and it acts a bit runny at those rpms (4.5-6k). Explorer does just fine at normal RPMs. It has a new belt, new sparkplugs, and new oilfilter, and new timing chain and guard.

What bother me the most is the noise, also when I am in neutral and I put the pedal down I get a rattling noise...maybe catalytic converter due to engine cylinder misfires?

Any advice would be helpful here guys. Its a 2004 Ford Explorer XLT 4.0 V6. Automatic 4X4.

 

[jtj1903]

I know this doesn't help much but I have this same problem on my 1999. i really wanna know whats going on. I thought it may be my flywheel or the clutch rattling but i'm not what it is

 

[Fox Fader]

I had a 98 4.0 that had a slight rattle too. I took off the belt and started it and the rattle stopped. This told tme it wasn't in the CC. I think it had to do with the load on the main pulley, main bearing, I never found out, I just drove it.