I don't get it. After sorting out all electrical problems on the car, I now have an issue with a GM Goodwrench engine.

No compression on cylinder number 3!

All others check out fine, clyinder 3 has 0 compression. So i figured must be valvetrain. Looked for valves not opening, staying open. nope. So i went by the book squirted oil into the cylinder, and compression went up. So that should have meant rings are shot, on a new engine? So I decided to rip it apart and install new rings in that cylinder. Sure enough the engine has to come out cause of the awesome way the oil pan was designed. Spend all day and night to get it done in one day, only to fin out I still ahve 0 compression even with new rings! WTF! Cylinder walls looked fine, like new, no scuff marks on the piston. I'm lost for words.

 

Did you check for a damaged spark plug or bad plug wire ?
Was the cylinder getting fuel ? Ignition Coil > Check ? Head gasket leak in the area of bad cylinder ?
Valve seat problem on that cylinder ?

Check bad to see what other member's post > Good Luck

 

I did a compression test. Don't see what a spark plug could change. But yes the plug was changed 3 times ;-) . Yes the cylinder is getting fuel. Coils have been checked. No leaks in the old head gasket. BTW have never seen a head gasket that stuck so much to the block and the head. That sucker sealed big time.