Waiting for hydraulic rams to be rebuilt. what about changing the spark plugs to kill time? car has 20,000 miles, but is 12 years old. Just a waste of time and money,or a good idea? How about the coils?

 

plugs, sure...they're cheap. Coils, not until one gives you problems. Me and a couple others have purchased one extra coil, because when it fails, it gives no indication and I hate driving with a known misfiring engine....shudder at the thought. Trying to find one quickly can be challenging too, tried that once...Rock Auto was my source on this one.

 

Hey, Matt, I wonder if that would be a good list to have/build: Things you should keep on hand...

Maybe with ranges, <$100, $100-$500, $500-$1,000, Are You Kidding?

 

That's a spectacularly low mileage - I managed to put double that on an XJ40 in one year back in the early nineties!

The Jaguar recommended Scheduled Service interval on the XK8 is 10k miles OR 12 monthly, whichever comes first so you should be on Service No 12?

If the schedules have been followed, the plugs will have been changed despite the low mileage. Although likely to be perfectly OK at 20k even if they haven't been changed, spark plugs are a service item and as H2Oboy says are cheap. Coils are not a service item and would be replaced if defective and not on a time or mileage basis.

Graham

 

The service interval on the plugs is 100k miles and I do not think time has much to do with plug wear or failure. Looking for something to do, have fun. But my philosophy is 'if it's not broke, don't fix it.

Old Irish saying: 'If you find a four leaf clover . . . you have too much time on your hands'.

 

Just give her another coat of wax/polish

 

The plugs are probably working fine as they should have at least a 60K mile life, but they may be seizing up in the bores, I would pull them and either put some anti-seize on them and reinstall until 60 K or so or just replace with new. My 05 XJ8 has 50K on it and when I pulled the plugs, two were getting hard to remove due to corrosion. Leaving plugs in too long can be frustrating upon removal attempts, as the gaskets on them keep nut buster from getting to the threads.

 

Just start at the front of the car, dissamble everything, cover with lube or anti-seize, and reassemble. (sorry Old, just too much time on my hands today. You're right about the plugs in these Al heads, can't be too careful!) But there is the possibility of screwing up a connector for a coil or some other brain cramp breaking something. I'd go paint the porch or something to make my wife happy first.

 

I've been thinking about changing my plugs, they might be original.
Haven't changed them since I've had the car, 50K on it since I got it.
Runs great and gets ~24-25 mpg on the freeway.
Mike