SPARK PLUGS AS A CONSUMABLE MAINTENANCE PART

Spark plug is ignition system component threaded into the cylinder head that contains centre and ground electrode extending into the cylinder head of an engine that form a gap across which high voltage arcs to ignite the compressed air fuel mixture In the combustion  chamber.
The spark plugs are produce with different design and heat ranges to be able obtain optimum engine performance. Starting from materials used to produce spark plugs have changed, steel and tungsten have fully been replaced by platinum and iridium for spark plug gaps and washer type seals on the plug bases are more usually conical seat today.
Presently spark plug gaps have also become much larger and are no longer adjustable on many spark plug types.  For instance the gap on iridium plugs should be checked and compare to your vehicle manufacturer’s specification, but never adjusted.  If the gap is improper, the spark plug should be replaced.
Spark plugs changes in design and countless other engine improvement have resulted in spark plugs that can lasts up to 100,000 – 150,000km and save you more cost compare to the rounded edge of centre electrode spark plugs.  The platinum and iridium spark plugs can be identify with a sharp pin edge centre electrode.
WHEN TO REPLACE YOUR SPARK PLUGS:
                          

 WORN OUT SPARK PLUG:

Spark plug is to be replaced when it wear out during period maintenance service checks if the gap between the center and the ground electrode becomes wider

                                  To manage and prevent other much more expensive problems, spark plugs must be replaced when they wear out.  The best guide is the manufacturer’s specification base on mileage recommendation. Not replacing spark plugs in time can result in poor engine performance(engine hesitation), high fuel consumption, damaging ignition coils and other components.

CARBON TRACKING:
The spark fires between the top of the plug and the base, across the ceramic shell.  This leaves a characteristic carbon track on the insulator.  It also causes the plug to misfire.
                        
A spark plug causing misfiring can extremely damage an engine. If spark plug fails to fire, the air- fuel mixture in the cylinder is not burned.  This unburned gases enters the catalytic converter, where it can rapidly increases the temperature. A misfiring spark plug can severely destroy an expensive catalytic converter in the exhaust system in a matter of minutes.

COMPRESSION LEAKAGE:
Spark plugs can leak compression around their bases appearing in yellowish colour.  When this occurs, excessively hot compression-gas may destroy coil-on-plug type of ignition coils. Compression leakage at the ceramic base results from age and can result to engine pinging and detonation.

Ping: A mild noise the engine.

Detonation: An occurrence in the internal combustion of an engine, where the compress air-fuel mixture explodes violently instead of burning smoothly.

Always have spark plugs inspected, when mileage approaches the recommended interval as guided by manufacturer’s specification. For instance if the recommended replacement interval is 100,000km, two or more plugs might be removed for inspection around 80,000km. It remains good advice to check spark plugs between 10,000 – 20,000 kilometres because they can stop functioning properly at any time. They may last much longer than expected but it is best to avoid any unpleasant surprises on the road by checking them regularly.
Subscribing to the right design and heat range spark plug maximizes your engine performance at peak and your vehicle usage from off road.