Engine has always been noisy (ticking & rattle) and definitely suffered from a lack of PM before I got it in '08 with 125K on it. Friday a new tapping & minor squeal sound started; louder on the right side (rear as installed in Caravan). Eliminated accessories and catalytic converter as possible causes. Suspected a rod bearing so I pulled the oil pan on Friday to find rods & mains looking and feeling okay. Noted definite slop and clatter in the timing chain. Pulled the engine out today, removed timing cover and put a piece of wood against the damper to stop the chain from making noise. Turned the engine over by hand, can't hear tapping or squeal as when running. Pulled the right side valve cover off, believe it's the #3 intake valve not moving as much as the other valves. This engine was cruddy before I got it, and I still found a good bit of crud under this cover. No metal shavings anywhere.

Question is - Can the timing and lifter issue cause the tapping and squealing sounds? What next? I don't mind putting some more money into this engine to keep it going but I don't want to be stupid in throwing good money after bad. All input is much appreciated.

 

Lifters will definitely cause tapping sounds.
As far as the squealing, I would venture to say a guide or tensioner for the chain.

 

I'm starting to wonder if it couldn't be the roller on one of the lifters that's causing the squeal. Getting ready to put the '93 engine in, but I pulled the chain off the '92 yesterday, can't feel or hear any slop in the crank/rods. No end play in the cam either. Engine definitely needs to be cleaned out though, it's nasty cruddy.

 

If they are roller rockers like the 3.0s then it's possible.