www.jec.org.uk

It is worthwhile taking time to remove all of the bolts holding the coil pack covers in place as well as those holding the coils in place and putting a small amount of copper based grease onto the threads.

Steel bolts were used that go into brass inserts moulded into the cover body (and the cam cover body). Over time they can corrode (due to dissimilar metals being in contact with each other) and then seize in place. Once they have seized then it usually results in the insert coming detached from the moulding.

Regards,

David

How easy are they to change and which are the best and the gap thanx.Had a look at some NGK i think they are permolite?came highly reccomended £56 this guy fixes them to his v8 any comments.

A little bit of copperslip would not do any harm on the threads.Most important is not to over tighten them.

Al

The spark plugs are not too bad to change provided you have the right tools and a lot easier to change than on some cars I have worked on.

I would recommend using a magnetic spark plug socket for removing plugs on the X308 due to how deep they are in the cylinder head. It is best the change them one at a time so that you do not get the leads to the coils mixed up.

The type of spark plug to use depends on the age of the engine. NGK list four types for the X308 4.0L engine. Use the NGK Partfinder website to find the part number for the plug that fits your car. Shop around for plugs as the prices vary considerably. In the past I have occasionally imported plugs from the States (back when the exchange rate was better) as it was cheaper to buy and ship them from there than to purchase them at trade prices in the UK.

The NGK plugs come pre-gapped and should not be adjusted.

Depending on how long it has been since the plugs were last changed, you may need to also replace the rubber boot on the ignition coil that goes over the spark plug. It is possible to purchase just the rubber section and not a complete coil on plug assembly.

Regards,

David