Quote Originally Posted by OmniLuvr View Post
i just had a vehicle come in today with ZERO compression, ecotec chevy caviler, compression was 68-56-47-0, when i pulled the valve cover the timing chain was broken, the only cyl that had ZERO compression was the one with no intake or exhaust flow escaping... even the ones that had valves open made some sort of compression.

i have never gotten to check the compression on a vehicle with a missing piston crown, but i have with large holes from detonation to foreign objects, and they still made compression. my SC still made 92 psi of compression and the 4th cyl head gasket was so bad that i could watch each firing event purge from the radiator fill, and it literally looked like a steam engine.
Fascinating these infernal combustion engines. I can't imagine what I'll find when I pull the head this weekend.