Heavy noise in engine

When I was on the way home I heard a light sound in the engine valves. I inspected the oil was almost empty, I filled it with oil 20-50 castrol oil and 10-30 oil I do not know the brand. Then I heard a heavy sound of the valves. When I pressed the gas pedal suddenly, there is no torque on engine and high sound if I pressed the pedal slowly there is no sound. I checked the valve clearance and distributor it is doing well but there is no ignition in three and four cylinder. When I pull the wire of spark plug on cylinder number four the engine still running and the three same thing. The engine is z24