This engine has 6 plugs - 3 at the front and 3 at the rear. It is the rear three that are difficult to access. In fact it is rumoured that many garage never changes these on a ‘full service’, but still charge for them.
To change the front 3 first remove the plastic engine cover and note the position of the 3 plug leads. These are fitted with tight rubber caps which can be difficult to remove. The plugs are located below these caps in a deep, tube type recess in the cylinder manifold, which necessitates using a 6 inch extension on the plug socket to locate on the plug. The plugs are of the small (19mm) type and therefore you need a socket and extension to fit this size. Always keep the socket vertical to the plug when removing, as a broken plug insulator is difficult to remove. When refitting the plug leads to the new plugs, the rubber sealing caps must be pushed down tight to give a good seal into the manifold. If they protrude when first fitted they will locate properly when the engine has been hot for a while.
The rear 3 plugs are located similarly to the front 3, but are far more difficult to access. Firstly remove the small hex screws holding the coil pack in position, and then move it away to gain access to the plug caps and plugs, which is still difficult. If the leads are unplugged from the module, make a note of their original positions. Change one plug at a time, moving the ignition leads as required to gain access.
A 6 inch extension on the plug socket, as used on the front plugs, will not, unfortunately, fit down the access tube of the rear plugs, as its top end fouls on the rear bulkhead when trying to enter the plug recess, which is angled to the bulkhead. This necessities using 3 small 2 inch extension pieces, which are inserted individually and joined together as they are inserted. I advise taping the plug socket to the first extension piece to prevent it falling off. Removal of the plugs is then identical to the front set. Do not over tighten when refitting, a quarter turn from hand tight is sufficient.
Best of luck with the job. The rear three plugs are a pain, with difficult access, but at least you know they have been replaced if you do it yourself.
The official garage method is to remove the upper and lower inlet manifolds to access the plugs, which then entails the purchase of new gaskets and is a major, expensive job.
Kayball, December 2009
