Re: Marbles in drivetrain
What you are hearing is called detonation. It is the sound of the fuel/air mixture igniting before the spark plug ignites while the piston is still traveling up to the top of the cylinder. Ignore it and you will most likely burn a hole in your piston, break the piston, etc.. It can be caused by a number of factors. Ignition timing too far advanced, too hot of a spark plug, carbon buildup in the combustion chamber, poor fuel, vaccuum leaks, lean fuel mixture, and/or ignition components (cap,rotor,spark plug wires, spark plugs) which are in poor condition. Your best bet to attempt to cure it is to do a complete tune up. Change the distributor cap, rotor, spark plug wires and plugs as well as checking the timing. Also check the condition of your vaccuum lines and replace any questionable ones. A vaccuum leak can cause a lean condition which may cause detonation. Try those first and seek more help from this BBS if it doesn't go away.