Hi all when going at 50 mph the car starts shaking and looses power not go over 50 mph intrying to do so the shaking gets worse is it a sencer ????

 

Sorry my jag is a xj8 3.2 year 2000

 

Power on and off, or only power on? If it is an engine is-fire, it will only be power on and it will generate a code. Always start with the code.

If it is power off too, then we need to look at wheels/tires/drive shaft.

 

Sorry what do you mean power on or off do you mean throttle??

 

He does. And is-fire -> mis-fire (misfire).

Sounds likely to be bad coil(s). Worth looking in case dirt/water/oil on any of them / in plug wells.

 

Check your air filter. It may need changing and starving for air at highway speeds.
Also check for any DTCs.

 

Try posting your message in the X308 forum, the one for your car. You should get a response from more people.