Toyota Repair: 97 4Runner Valve Tapping/Knocking, 22re engine, srewdriver

Question
I have a 1997 4 Runner wit the 22RE engine, manual Trans. The car has a very loud tapping sound which seems to eminate from the valve train. The noise is a pretty loud tapping that increases volume at higher RPM. It does not sound like a lower end knock which get louder with load. It's a typical tappet sound but real loud. Compression was good in all cylinders--90psi on first crank rising to 180 after 3 compressions. Checked valve clearances and all were within spec. I'm absolutely lost as to what this could be. Someone suggested timing chain problem but it is hard for me to imagine a chain sounding like a tappet. Appreciate any help!!!

Answer
Keep in mind, I cant actually hear it.
I would doubt T-chain also.
Ive seen carbon do it.
Ive seen a sticking valve do it. That would explain the valve clearence being ok.
Try pulling the plug wires, one at a time and see if the sound changes and you can isolate it to one cylinder.
Can you give me a location of the noise?
If you dont have an auto stethascope. put a long srewdriver to your ear and try different places to see where its loudest.



Mike