How do you repair a 1996 Jaguar XJ6 that is running rough and has a code of multiple cylinder misfires?

Answer 1

I'm not sure how old this question is since these are not date stamped. I am new to this site and may have purchased your car since you posted this. Anyway here goes.

I just purchased a 1996 Jaguar XJ6 from a Dealer who just traded it in the same day. The check engine light was on but the car looked clean and ran great so I thought I would take a chance. This was an incredible risk as I have never owned a Jaguar. I have learned everything so far from message boards.

The first thing I purchased was a handheld OBD II code reader from AutoZone to read the check engine codes. It was the best $90.00 I ever spent. Anyway I trapped similar cylinder misfire codes and was able to determine it was the Ignition Coil. There is one per cylinder so be prepared to spend some money. I had one go bad and the car suddenly ran bad so I was able to trace the problem quite easily. Once I trapped the code I could tell which cylinder, swap two coils, and verify the problem followed the coil.

My suggestion is to first replace your spark plugs. I suggest Bosch Platinum +4 from Auto Zone. If that does not resolve the problem you need to replace your ignition coils. My car has 90,000 miles so I replaced all 6. AutoZone can actually get them for approx. $100.00 per coil. Don't be too quick to choke as everyone else wants $280.00-$350.00 per coil.

I have also had the same problem on a 1995 Vanden Plas and the solution was simple, expensive and difficult to locate. The part you will need is a valve cover (OEM #NBC2564CB) and since they are no longer being inventoried by the manufacturer, it will be difficult to find. Expect to pay about $845.00 US to get the part. What happens is the matterial that lines the inside of the cover deteriorates and allows the spark plugs to arc, causing the problems you brought up.

Good luck.