Ive had 4 different belts on my car today... the old one, the second one, then one that was the wrong size, and then the final one.
I am thinking that its either a broken/damaged motor mount, or the HB. At about 4000 RPM it just rattles and vibrates. When it drops revs down to idle it vibrates, and once it gets to idle you cant even notice it.
Ok, this is wierd. I drove my truck today and when i got home, I started it to check all teh wores again, and when I pull off a wire it changes nothing, no matter what wire it is. then I put them all back on and noticed that it wasnt shaking at all anymore. So I though maybe it would shake after it was warmed up. So I ran it and it never shook. It runs like it did when I bought it. Anyone know wtf is going on. Im still going to get someone to look at it friday though ,and if it starts shaking again, Im going to park it.