I have 2005 Jaguar XJ8L with only 48K miles.
The front suspension is down. Is the compressor, struts or shocks?? Any sugestions??

Was the compressor running when you start your car? If not, check the fuse and relay first.
If it is running but car is not raising, it could be the compressor piston seal. You can replace the seal.
You can also check the pressure at the hoses and see how much pressure in the tubes and confirm if the compressor is making enough pressure.

Do you have "air suspension fault" displayed on the display window on the instrument panel ? If so, there will be fault codes and these need reading to give clues as to what is causing the problem. You may have an air leak at the front, or the height sensor is duff.

When did the car drop down ? Was it after any work was done on the car ?