A local and reliable Jaguar mechanic found that my rough idle was being caused by failing ignition coils in # 5 and # 6. My 1995 XJS has 140,000 miles, and I can see that age and use may have caught up. My question: how expensive must I go (I'm a 90% sort of guy) to have good firing and function? I have found them at JagBits at $100 for each coil, and I have seen six-packs on eBay from $120 to $350. (A used and retested set of Lucas Coils are up for bid starting at $50.)

Also, is installation pretty straight-forward -- something I can do in the comfort of my own garage?

Thanks for any insight. Gary

 

There is a huge long discussion on coils in the X300 section led by member Doug. I think the engine and coils are the same.

 

You can get good firing and function from the $50 cheapies.

If you want good firing and function for *more than 8-12 months* you'll need to seek out and buy the true OEM coils. These are hard to find. Many vendors advertise OEM stuff but are not selling actual OEM stuff.

Presently it appears that member Japthug has some of the good ones

Here's the thread

https://www.jaguarforums.com/forum/x...0-coils-93966/






Dead simple. A torx bit to remove the coil cover. An 8mm wrench or socket to remove coil hold-down bolt. Release and wriggle-off wiring connector. Pull coil out. Reverse to reassemble. That's it.

Cheers
DD

 

May want to put some dilectric grease on the inside of the rubber boot so it makes a nice weathertight seal on to the spark plugs.

Definitely an easy install.

You will need a T-27 torx bit to take the plastic cover off, then a simple 8mm socket will do the trick.

You can do a search on ignition coils here and on the X300 section. It will be quite informative.