2000 Oldsmobile Alero No Compression

is it just one cylinder or all cylinders lack compression? cracked or broken piston will cause a loss of compression, as will cracked or broken rings. The failure of a head gasket will also cause a loss of compression, as will broken, cracked or badly worn valves or valve seats. A crack in the cylinder itself (either the sleeve or the engine block), or a crack in the head itself will cause a loss of compression. A problem with the plug threads or the threads in the head (for engines that have plugs) can cause loss of compression, and injectors (for engines that have them) can leak around the threads, either because the injector threads or the threads in the head have been damaged.

pistons are in perfect shape, the plugs and valaves and basically everything else you have described we already checked and look fine, in fact most of the parts are new. We even checked the push rods incase one or two were in the wrong order, but they were fine. Put a little oil in the cylinders to create a seal and still no turn over. This car is honestly a mystery diagnosis. and it is all the cylinders doing this.

is it no compression or just low? im assuming you have checked timing belt..?