loud pinging
 

Trying to diagnose a problem. Engine runs good but when I reach 2500 rpms a loud vibration and noise happens. Tranny shifts at all the proper ranges. came to a stop yesterday and belts squealed and then a loud pinging started. Sounds like a bolt rattling around. Checked all rocker arms and valves none broke all push rods are straight and clean. Could something in the torque converter or bell housing cause this?

Where exactly is the noise coming from?

pinging
 

the sound seem to travel on the top end of the motor but several technicians just say that I need a new motor. They cant figure out the problem. I thought it was from the bottom. If it was a connecting rod broken I would get a miss in one cylinder, same goes for wrist pin. It has become a loud rattle and I'm thinking that it may be coming from a torque converter or broken flywheel maybe backed out a bolt?

If you had a problem with your tranny you'd see something by now like getting worse or see some symptoms of problems in the tranny.

If it sounds like there is marbles then your having some issues in the motor related side. Any metal in the oil? Check the pan?