My 1988 XJS

It is not uncommon for the battery light to stay on for 20-30 seconds after start-up and at the same time the large yellow light with an electrical bolt in it. This is just the system nutralizing. If you do not see any lights out check the tag lights. That is normally the problem. You need to read the manual because the light you describe is also a handbrake warning back-up system. Xj-s hand brakes are fly-away so you may be driving with it on--well you were cause its burned out now. What you did not say about your vibration is what type of wheels you have. If you have factory wheels do what steve said. If you have those cheap a-- Daytons (thiugh not cheap to buy) there is your problem. They will not last on these cars (too heavy) and if they are old they are out of round, bent, warped,etc.

George Camp

Alec,

As far as the dash lights go, the lightbulb with the X through it means that a bulb is out somewhere. That light and the ABS light (though I think your car is pre-ABS) will stay on for a short time after you start, and then go out. If the bulb light stays on, then that means you have a bulb out. Check all the exterior lights. If the ABS light stays on, it means there is a problem with the brake system which should be checked out immediately. Are you sure the other light is a battery light? What does the gauge show in terms of charging/discharging? Read your owner's manual and "The Book"... they will explain about the lights.

As far as the shimmy goes, speed related shimmies usually mean that the tires are out of balance. Usually, the front tires. What type of tires do you have? How old are they? Be careful. These cars require speed rated tires (original equipment was Pirelli P600's -- V rated tires, 225/60-15's I think -- don't quote me on the size, check your manual).

The P600's are very expensive and very hard to find. Check the XJS archieves on Jag-lovers and Kirby Palm's "Book" on alternate tires. Many people like the Pirelli P6000's, I believe, but other tires are available. You need the speed rated tires because the suspension is tuned based on sidewall rigidity. Non-speed rated tires have different sidewall stiffness and can seriously effect the cars handling, especially at high speed or in emergency situations. Old tires can be dangerous as they can disintegrate on you at speed. Not a good thing. Also, any tires you buy or the ones you have if proper and still serviceable, MUST be dynamically balanced (computerized spin balancing).

If the tires are properly balanced and you still have the shimmy, check the front end -- shocks, bushings, ball joints, wheel bearings, alignment. Also, since it sounds like you like to go (too) fast, have you checked the brakes (pads and rotors) and bled the brakes? If your car does not have ABS, bleeding the brakes is simple and should be done annually if you insist on driving fast -- nothing is more important than being able to stop the car. If the car has ABS, there is a special procedure for bleeding; be sure to follow the instructions exactly or have it done by a someone who knows how.

The V-12 engine takes 11 1/2 quarts of oil, including the filter. Yes, 11 1/2. Read the manual for capacities. Be sure you start checking the dipstick before you put all 11 1/2 in. You don't want to overfill it. Be sure to use a good quality 20W-50 motor oil (I use Castrol GTX, but any good quality oil will do as long as it is the right viscosity). Opinions differ on whether to use one of the "high mileage" oils. That's up to you.

Old engines, especially these, tend to leak a lot of oil, from places you can't imagine. Be careful if you decide to start tightening things to stop leaks. Check the torque specs and use a torque wrench. Don't overtighten bolts, it will only make things worse. If you are burning a lot of oil (serious amount of blue smoke), check the compression in all cylinders and try to locate the source to avoid serious engine damage. It is normal for these engines to blow some smoke on cold startup. Some oil leaks down the valve guides into the cylinders when it sits. But the smoke should stop after a minute or two of warm-up. If it continues, check it out.

Let us know how things go,
Steve Weinstein