I have a 4.0 with 45,000 miles on it. The car was running great. Then it all went to crap. It started to misfire like crazy. So i went to find of which
banks where misfiring. It was #1. Changed the coil and went ahead a changed all of the sparkplugs. Worked fine for about 4 days. Went back to
check which banks were misfiring it was #2,#3. So i changed the coils for those. It ran fine for 1 day. Went back to get it checked again, they
said it was banks 1,2,3. I was like no way i just changed those. So i thought it was just getting an old reading b/c i never cleared out the old
readings. So i cleared out the old readings. Then i was driving back home from autozone and sure as ****, started to run like ****, check engine
light came back on. I was so fed up that i haven't went back to get a reading yet. Just to give you alittle info about me. I know how to work on
cars. I'm no joesmoe, but i don't know everything acourse. I know the wires are good with no cuts, no oil was anywhere to be found around the
plugs. I just need some help on these Jaguar's. Please any comments are helpful, I really don't want to take it in.

 

Hello. I had the same problem with my 2000 S-Type 4.0. I went ahead and replaced all 8 ignition coils in addition to the spark plugs. My car runs great now. If you go to Autozone, Advance Auto Parts or Murray's Discount Auto, they all sell ignition coils made by Wells. These come with a lifetime warranty so no need to worry if they burn out again. As for the OEM Stock ignition coils, it is best to get rid of them as soon as possible as they are prone to fail at around 50,000 miles. I know that the ignition coils aren't cheap ($55 each) but replacing them all will save you some hassle. Also be sure to check that the electrical connectors to the fuel injection line are all snug (8 total, 4 on each side directly above the valve cover). The plastic clips that keep them from coming off tend to break easy. Hope this helps and good luck.