ok, my daughter in law drove her 2004 saturn ion to work on thursday and it wouldn't start afterwards. i went to try and jump start it but it made the unmistakable sound of no compression, first instinct was timing chain, no such luck it is still in one piece and tight, next was compression check, 0psi in all 4 cyl. is it possible that the timing chain jummped? i have never seen and engine lose compression in all cylinders. i really don't want to get into a ring job if i don't have to.