I have a 1995 Dodge Avenger. Love the car to death. A noise just started that i have never heard before. Its a loud rattling noise. The noise gets louder when i touch the gas, but makes a constant rattling noise when im not accelerating, or touching the gas when its parked. The noise seems to be coming from the block. I just took the valve off, and the exaust manifold, but see no problems...it sounded like the noise could be a bad piston ( i sure hope not ). and unfortunatly, i cant start up my car again to hear the noise again to pin point where the rattling is coming from due to my valve cover being removed, cuz then oil will spit all over the place i think. Any ideas what this noise could be?