An exhaust valve(s) staying open upon compression.
Bad are burnt intake or exhaust valve. Pistion rings broken, Burned pistion. Blown head gasket. That is all that would cause no compression are a loss of compression.
The intake and exhaust pushrods are different lengths. If you mix them up you can cause bent valves upon the first crank which would cause a no compression condition.
Exhaust of an engine is a gas.
stopped up exhaust system
Compression can cause loss of data or information, reduced quality of the compressed file, and potential compatibility issues with certain devices or software. It can also make it harder to edit or modify the compressed file.
Burned or bent intake or exhaust valve. Valves adjusted to tight, Burned pistion. Head gasket blowed between 2 cylinders.
You have a misfire. Check the coil packs. If the first answer don't help also check your spark plugs and check your motor mounts and if that not it get you exhaust checked or do a compression test.
exhaust?
It will not close quickly or completely, on intake it will cause loss of compression and backfiring, on exhaust also loss of compression. There may also be some noise from piston hitting valve, and possible damage.
Exhaust leaks close to the engine.
It would be unburnt fuel