anyone has thinking about replacing your rectractable antenna on your earlier XK with any kind of shorter non-rectractable antenna?

Also, when I was driving on Highway today, tried to speed up and step on the gas paddle(I was driving at speed of around 60mph), I felt a little shake from the engine bay, then next thing I noticed, the check engine came on and there was a message that says "Engine fault, poor vehcile performance". this message pops up with the little shake from the engine, every time I step on the gas paddle . I was on my way home, so
after I get off the freeway, I stop on the side of the street, and turned off engine and turned it back on after a few minutes. It drives fine as normal and don't see the message or feeling the engine shake no more but the check engine light stays on. Since there is an local Jag shop which is less than 10 blocks away from my house, I've taken the car to them and have them look at it anyway. So, after they did a reading
on my car there 8 code came up and was told that there were two of them are about miss fire, and the rest of them could be just the cost by the miss fire problem. Then they have reset the check engine light for me and tell me to keep on driving it till the check engine light came on again, then bring the car back to them to do another reading to see what the real problem is.

So, I am wonderning if any XK owner had run into this kind of problem before? Am I looking at something really bad here? or just something common?

 

relatively common on the 4.0L (assume that's what you have since nothing in your post about engine size or model year)

Coils fail due to water and/or oil getting into the spark plug wells..the 4.0 has covers that really don't seal well over the plugs and coils...if you had the codes written down, you can actually find out which cylinders were misfiring from our FAQ thread in this subform...remove the coils for said cylinders, check the well for liquids and trace the source, check the spark plug, and assess from there. Usually, if plug is good (not fouled, and properly gapped) for a trouble cylinder, its most often the coil or a wiring/connector attached to the coil.

The highway speed hesitation also reminds me of throttle body issues, specifically the connector to it...but with misfire codes present, best to troubleshoot them first.

 

After I have read your reply, I guess everything makes sense now. cause this morning I had my car detailed which including a steam clean in the engine bay. and since you mentioned the cover dosen't seal well for the plugs and coils, chances are there may be some moist have got in there. and after a while of driving, the moist is gone by the engine bay's high temp.

 

The answer to your antenna is I installed a hidden antenna that I purchased online and installed it under the back seat. Went to radio shack and bought connectors to splice this into the antenna wire at the antenna and pulled the fuse for the antenna. Now no more antenna sticking up when I drive and reception is just as good. I know I should of taken pictures and when I get a chance I will as well as supplying the info of what I installed

 

A previous owner put a standard antenna on my car. It doesn't look good. Trying to find a cheap original, powered antenna to replace it, but need the mounts as well. When I find one, I'll put a switch in to operate it. Most of the time I listen to either the engine or CDs, hardly ever listen to the radio so I'd like for it to stay down.

 

ANY moisture on that throttle body connector will give the same codes too...looks like you have a little dual-correction to undergo. If it were me, I'd pull both banks of those covers, and pop off the coils, dry the spark plug wells by sticking paper towels into it (with the plugs still in of course), then a little air-dry time in the garage.

NExt, I'd take that connector on the throttle body, unsnap it, and put some electrical contact cleaner on them, leave them open to dry for awhile, then put it all back together and drive it. It may take a few drive cycles to clear the check engine light (if its still on) by itself, unless you have a scanner to clear them yourself.

Do it soon, driving with a misfire (worse with multiple cylinders) can kill your catalytic converters in no time...ask my mom, she drove a couple months with one on her lincoln, and now she's buying a new cat for her delay. Cat's are not cheap.

Jaguar engine bays DO NOT LIKE steam or high pressure sprays...we clean ours with more rags, controlled cleaner spraying, and sometimes a low-flow from the hose directed over specific areas...never on electrical connections, modules, or atop those covers.