broken ring
 

is it possible to remove pistons in a 1.8 from below without removing the engine? thanks.

Technically yes, but alot of effort. You would need to remove the transmission, then the sump, then the crankshaft. or remove the sump, then the cylinder head.

Thanks, I want to avoid pulling the engine and head. why does the head have to come off in conjunction w/ the sump? will the pistons come out from below? the crank can be removed from some fore/aft engines (ford, dodge, Chevy), but I've never heard of it on an engine mounted cross-way. :)

The Pistons are bolted to the crankshaft and it bolts to the transmission.