Hello, I was laughing at the used Astra F with gas system and C16nz.. Engine ran already on purchase only on 3 cylinders, and had oil in the water,I actually thought that this would be only the ZK seal… But a mechanic measured with me today times compression… Cylinder, from the timing belt, 4, 2 and 1 all have between 11 and 12 bar, cylinder 3 only about 2 bar… Engine runs as said only on 3 cylinders, but from about 4000 turns again calmly, and then pulls also properly. abe r whether this is due to the speed or because the cylinder is working again I don’t know… What is more likely that the valves from the cylinder are broken or the piston rings????? car has run about 100tkm with gas….