I have a 99 Silverado 5.3 liter with an automatic transmission with the factory tow package. It recently developed pinging noise which is coming from the flywheel or torgue converter. I checked the three torque converter bolts, but they were tight. I dropped the tranny thinking I had a cracked flywheel. However, the flywheel is okay. While removing the flywheel for an inspection under bright light I hit the fly wheel and discovered a noise similar to the noise I had been hearing. Can anyone give any ideas what my problem might be?

 

If you can, start the engine, and look at the flywheel, look at all the parts and pieces in the intermediate area, and see if you can see whats hitting it, other than that, i have no idea.