This car has a combined coil pack on top of the engine - when this is unbolted and air pipes removed, the 4 plug caps come off as one. Careful with it!
John
November 2009
A diesel engine uses the heat of compression to initiate ignition to burn the fuel.
In a petrol engine the fuel/air mixture is ignited by a spark plug.
Spark plugs each have a large black wire running to a plastic cap on top of them - on the top of the engine...