well, pistons are out (pics later) and i cant see ANY evidnece of anything wrong, not obvious evidence anyway. rings look good, no cracks in the piston, no damage to the cylinder wall. each piston looks just like the other in everyway!

What gives? why did my #3 comp. hit the shitter? i hate to ask this question after the fact but: is it possible that to low of an oil viscosity could have done this buy mimiking the signs of a blown motor? my troubles began soon after i put in 5w20 synthetic.

well, let the hypothisizing begin...

tim

What about the valves? They can also cause compression issues.

Don't forget that a blown head gasket, or a warped head can cause low comp readings too...

How did you head gasket look?
Have you checked the head for distortion?

Lee.

Look at the valve seats and Like^^ said.
Did you do the oil leak down test? If so what were the results? If it failed the oil leak down test than it means head gasket or valves.

Take the rings off of the piston. When we say cracked piston, the rings lands have hairline cracks in them, that can be hard to see. When you take the rings off the piston, that chunk that is cracked will usually fall right out..