I attempted the plug removal process today. It wasn't bad at all. These plugs are the original plugs. 71k on them, as you can see they are shot. The cap and rotor are original as well. I lightly sanded the rotor and contacts in the cap, lets see how it goes. The front 2 plugs were challenging. I took 4b out first it was the easiest and the white extension part of the plug broke off, I was like, I'm stopping now because I do not want to break a plug in those heads. First thing, Jaguar did use anti seize on these plugs when they were originally installed, and its proof the anti seize works. They all broke their seal very easily. So what I did on 1A and 2A was use a long extension and a hammer and tapped the extended part of the plug off. Mine were brittle and old, I don't suggest you doing it, but then again its my car. The pieces broke off like a piece of candy. I was then able to put a normal size 5/8s socket on the plug and a universal and out they came. The original spark plug wrench was just what the doctor ordered.

 

I would suggest you replace the cap and rotor as long as you have it off. Those Marelli rotors are notorious for failure.
When you put the plugs back in, I believe they are supposed to be torqued to 8 lbs, which isn't much, so be careful not to over tighten them.
A new set of wires, plugs, cap and rotor just might be all she needed if they're all original!

 

I've had the dreaded Marelli rotor failure on both my 89.5 XJSs. This time I followed Kirby's advice and did the window sealant treatment. The cap looked fine, but I replaced it anyway while I was in there. The aftermarket cap is awfully light compared to the Marelli original.

 

1a and 2b, whoaa...to put back in is like a brain teaser...still trying to do it.

 

Have you lifted the compressor?

Cheers
DD

 

I completely removed my A/C (mine is a convertible, seemed pointless) and now I can change the plugs in a total of about 10 min.

 

When I replaced my plugs last month, I indexed each one. Worth the effort I think. It ensures each plug is firing towards the combustion chamber...which would not have been the case otherwise.

 

I don't mean to sound ignorant...but you indexed each one? I have no idea what that means...

 

I did now. I took it off, I'm changing belts anyway.