I am going to jump off a bridge

Hello all: I bought a 2002 Ford Explorer with 42,000 miles on it. I love the truck, excepet for these niggling issues.

1. Between 2300 and 2800 RPM I hear a noise like metal being ground up in a blender.

1. there is an annoying squeak that comes from the rear end of the truck when I go over bumps. I was wondering if anyone else has experienced this.

2. The truck idles roughly, I cleaned out the MAF and changed the air filter. I also had it scanned, and there were no trouble codes found. Any clues as to what may be causing this?

Thank you very much.

Homerjay.