Hi Colby,

As JagV8 has already stated, when the Check Engine Light blinks, it is trying to tell you to pull the car over and stop at the first opportunity to avoid damage to costly components like the catalytic converters, oxygen sensors, engine valves, etc. The blinking CEL means excessive misfires are occurring. This is the cause of the rough running you have noticed. It should never run roughly simply because you only drive it every week or two.

You really need to have the computers scanned by a tool capable of communicating correctly with your car. In my experience, not all scan tools like to communicate with the systems in the X308, and this was probably the issue for your local Auto Zone. I have a very high-end Autel scan tool that often does not like my X308, so more often I use an old inexpensive Launch CReader VIII (I'm not sure if this model is still available). I also have the official Jaguar dealership IDS laptop-based diagnostic system, but it is slow to use, so I rarely bother.

A relaively simple alternative test would be to remove the ignition coil covers and carefully disconnect one coil at a time, listening to the engine rpm. Usually, when you disconnect the coil in a working cylinder, the engine rpm will drop somewhat and the engine will run roughly. When you disconnect a coil and the engine rpm does not change, you have found a misfiring cylinder.

It is very likely that with a scan tool that can communicate with your vehicle, you will find misfire codes such as P0300, P0301 to P0308, and P1313 to P1316. Here are examples of what these codes mean:




It is really imperative that you diagnose and repair this condition as soon as possible or risk very expensive damage to the catalytic converters or engine.

P.S. Since thread titles like "Answers please" may not attract members who may have pertinent knowledge to read and contribute to your thread, I have taken the liberty of renaming your thread to better reflect that nature of your inquiry.

Cheers,

Don