Is there any rule of thumb that says when the sparkplugs/wires and fuel filter should be changed? I have a 2001 XKE convertible with approximately 84,500 miles on it and wonder if it is time to change, since I am getting restricted performance codes related to engine misfiring. This is only an intermittent problem and I am puzzled by what might be causing it. Could it be the spark plugs, the wires, the fuel injectors or the fuel filter? How do I tell my mechanic to troubleshoot this problem so I don't get soaked with a huge repair bill that does not fix the problem?

 

Get yourself a code reader, you will probably find it is coil packs more than plugs, each plug has its own coil so no need for wires....... For the home mechanic a code reader is a must have with these cars, plenty of info on here about them.

 

Most likely the coil packs.

 

Thanks for everyone's help. The mechanic diagnosed the issue as being the number 3 coil pack and wanted to thank the members of the forum for pointing him in the right direction.

 

Hey:

I got my car a couple of years ago. 82000 miles 99 xk8 convert. She was missing a bit so cleaned the maf and part load breather and decided to change the sparkplugs. Car ran better but I did learn something. It is a good idea to change them even if they dont need it as a couple of mine were very very tight. I guess with age they tended to seize in a bit. So I would recommend at least maybe taking them out and putting anti seize compound on them as a just in case

Howard