Engine/Transmission (1994 - 1998) Help with Engine Issue very loud combustion noise and rough idle

[Taz]

At least and hope it's a combustion noise problem.



The truck has been idling rough for a while and I been trying to get around to diagnosing the issue. I have a brand new lift pump on the table ready to install but haven't had the time nor has the weather been accommodating.



Then about 3 weeks ago, I wake up to go to work and start the truck. Drive out of my driveway and notice something is GREATLY different in the idle of the truck, more than just being rough it sounds wrong. So I turn around and park it. Due to work and travel schedule I haven't laid a finger on it. Today I get my little old point&shoot camera out to video the noise coming from the engine compartment. It's extremely loud. I'm looking for anyone that can point me in the right direction as to things to start checking as a troubleshooting list. Just don't want to go stabbing in the dark with this problem.



The engine has 357k miles on it, bone stock. Driven hard but maintained.



Two youtube videos to listen to one from underneath the truck and one from above. You will notice the loud noise leaves shortly after getting off idle. But through the RPM range you can hear it's not a smooth rev up and still has a tad bit of noise throughout the throttle to WOT.



From below:

YouTube - Truck Recording 1



From above:

YouTube - Truck Engine Issues 2



ANY help is greatly appreciated.

 

[Dieseldemon]

Is this an auto trans? Sounds like a broken flexplate take the cover off the bottom and see if you can move the flexplate.

 

[Taz]

Yeah it's an auto!

That had not even crossed my mind!

 

[HerbW]

What did you find? When my torque converter went bad it sounded just like this. It was unbalanced and scalped the rear of my engine. This deposited metal shavings all over the flexplate as it warped around.

 

[Taz]

The torque converter bolts had come out and were making all kinds of noise with the flex plate!