Spark Knock

Spark Knock Points : spark knock, engine noise analysis, problems in internal combustion engines, ic, engine, auto diesel Pre-ignition or spark knock causes a metallic ringing sound, often described as a “ping”. Usually it is encountered when the engine is laboring or accelerating rapidly, or is overheated. Pre-ignition is caused by an incandescent particle of carbon or metal in the combustion chamber igniting the mixture prematurely while the piston is coming up on the compression stroke. This results in a very heavy pressure on the piston at the wrong time, causing the piston, the connecting rod, and the bearing to vibrate. This results in the sound known as spark knock. A fuel of too low an octane rating causes detonation most frequently. It burns too rapidly, resulting in a sudden and abnormal pressure against the piston.