Glow Plug for the 2.0L L-Series indirect injection diesel engine, screwed into the cylinder head so that its tip projects into the pre-combustion chamber. The glow plug is an electrically heated element that raises pre-chamber temperature before and during cranking. On a cold engine, compression alone does not lift the charge to the self-ignition temperature of diesel fuel, so the heated element supplies the additional heat that allows the injected fuel to light - the mechanism that governs cold starting. One plug is fitted per cylinder, so four are required for a complete engine. A single failed plug usually presents as extended cranking with rough running and white exhaust smoke on a cold start, clearing as the engine warms through. Plugs are normally replaced as a set, since the remaining units will have accumulated the same service life and heat cycling. Note: diesel applications only - this plug does not fit petrol variants.
