what is the procedure to remove the spark plugs? I don't want to mess with something without getting the information needed. 1994 XJS I6

thanks

 

I have the later AJ16 engine with the coil on plugs.

It's very straightforward.

Pull the plug wires off, unscrew the plugs using a 5/8" socket (test the size on the new socket first to make sure?). You may need a socket extension?
Smear some antiseize on the threads of the new plugs to make sure the plugs don't lock in.
Screw in the new plug, making sure it's gapped properly. (0.035")
Torque them to 19 ft-lbs.
Plug the wires back on. You're done.

I'd recommend sticking with Champion brand, although people like the NGKs here as well.

If you see oil in the wells, it's time to change the spark plug gaskets....also straightforward and easy.

 

this is my engine. i have pulled on the wires but i don't want to force anything. could it be that the plug boot is on very tight? i'm use to U.S. V-8 engines.

 

Yeah, the rubber plug boot seems to be tight, just grab it by the boot and pull. You might be able to shove in some kind of plastic wedge to break the seal/bond.

I know you know not to pull by the wires...

 

I sure do wish that the plugs on my V12 were so easy to reach! If you have a spark plug boot remover. It's just a flat pair of pliers with plastic covered jaws. Grab the top of the rubber boot and try to rotate it back and forth gently. I'm sure that the heat has bonded it to the cam cover. The boot pliers are available at any auto parts store.