Per the owner's manual, I see that the recommended spark plug for my '94 XJ6 is the Champion RC9YC. Normally, I'd go out and pick them up without a second thought, but I figured I'd do some checking as I am unfamiliar with the brand. Apparently, there's been a lot of quality problems with them, particularly a manufacturing fault that causes the threads to almost "weld" themselves into the engine head, despite the use of anti-seize compound.

I don't know if that's true or not, but it's enough to give me pause (paws, get it?) since I love my car. Is there another copper plug made by a more reputable manufacturer that I can use? Searching the internet didn't yield much of anything so far. Thanks, guys.

 

A little farther down the page: https://www.jaguarforums.com/forum/s...ad.php?t=46005

May have some information of interest to you. Hope this helps.

 

Like I said in the other thread, I'm a champion fan in my british car and truck.

 

mphilleo:
I'm currently using the Platinum Bosch FRB DPX 4202 plugs in the Jag with brilliant results. They are also what the PO had in the car when I got it. I've got Champions in the Model A, and they are brilliant too.
Cheers, Scott