Spark plugs are needed to start the engine and ensure its proper operation. As the fuel-air mix is compressed in the combustion chamber, a spark is generated between the electrodes on a plug, igniting the mix and releasing energy of which 20-30% powers the car. Worn plugs may disable the engine or result in a significant increase in fuel consumption. A typical symptom of a spark plug failure or a controller failure is difficulty starting the engine at low temperatures.
What are spark plugs?
Spark plugs are applied in petrol engines to produce a spark needed to ignite the fuel-air mixture in the cylinders. A spark is produced by the high voltage generated by the ignition coil and distributed to spark plugs by the distributor.
As spark plugs wear, their electrodes burn out and the spark generated by them becomes less powerful, resulting in unstable operation of the engine, problems with starting it, and, in extreme cases, failure of the ignition coil.
How are spark plugs replaced?
Replacing a spark plug requires disconnecting the ignition cables and removing the plugs from the engine cylinder by means of a special wrench. You have to be careful not to let the contaminants gathered around the base of the plug get into the cylinder. When fitting a new plug, make sure to set the distance between its electrodes by means of a special device called the clearance gauge. When fitting new plugs make sure they are properly positioned in the cylinder to avoid damaging the thread.
What to keep in mind?
When changing spark plugs a good idea is to check the condition of the distributor cap and rotor. After applying an appropriate torque to fit the plugs and after connecting the cables the engine should be turned on to check if the ignition system operates properly. Some cars may require being connected to a diagnostic computer to cancel the error codes resulting from the ignition system failure.
You should always replace both spark plugs as they have a similar useful life. Spark plugs should be replaced after each 40 thousand kilometres.