PNYXPRESS

Have you pulled the valve covers to and checked to make sure you dont have a broken rocker or valve spring?

Footay19

PNYEXPRESS I've kept that in the back of my head but have hesitated on it because the sound isn't coming from inside the valve cover or anywhere on the top of the engine. I used a stethoscope to locate the sound underneath near the timing chain and oil pump. That's why I'm thinking rod bearing but the sound im hearing is a little different than most rod bearings I've heard when they go bad. It's a light tapping sound instead of deeper knock. I've already put a lot of money into it. Might as well keep scratching things off the list.

PNYXPRESS

It may be a lifter if its coming from within the motor.

Footay19

So after I did the timing chain replacement and water pump job I had a CEL throwing out a code for bank 2 sensor 1 that was detecting a lean condition. I decided to just change out the O2 sensor hoping that was the case and miraculously I haven't heard any tapping since then. I also replaced spark plugs and wires. Think the wires, plugs and sensor problems could have been causing the noise?

fastbackford351

Could be excessive skirt to bore clearance.

Throw a couple shot glasses full of Lucas oil in.

Lucas takes away all kinds of funky noises.