Loud Clacking Noise

Does this have the safety feature where the hazard flashers activate when the doors are opened ? It may be the hazard relay clicking louder from wear .

Listen to this , is this the noise you hear .
GM 3 8 Engine Noise This is a 3.8 but can be also 3.1 , 3.4 gm v-6's engines

The first sound you describe is detonation or spark knock and is caused by a lot of things.. The second one is bad news. Could be a rod that is failing.

That sounds like a stuck lifter, have it inspected ASAP. Also verify there is enough oil in the engine.

Pull valve cover off and look for any bad lifters. Or could be piston rod. Sounds like sticky lifter. Not good.

This noise can be caused by a defective outboard (wheel end) front axle constant velocity joint (known as a "CV" Joint). This would be louder on turns, more noticeable at lower speeds and sharp turns. Next it could be valve train noise, this would come from the top of the engine and this could be related to the oil change if a piece of dirt got into the oil supply to the hydraulic camshaft followers. At this point you need a professional to listen to the noise to determine the exact cause.

soiunds like a wrist pin but more like a cracked piston,

could mean a lot,,,valve train,,,timing chain,,connecting rod, or risk pin,,that's the part that connects to the piston to the connecting rod that connects to the crack shaft,,if the sound is more louder on the bottom it could be that,,,if on the passenger side of car the motor noise is loader,,could be timing chain,,,try in locate the clacking noise first,,,

Sludge in the engine.

Go to online store reliable they have repair manuals I am sure you will get the solution.
Here's the link
Best Manuals