Hello all,
Have an 04 xj8 approaching 100k. Today while wiping under the hood I noticed that the round circular object on the left side of the motor was hissing and sounded like it was leaking air from it (pic attached)? What could this be?
Also the motor seems to have a ticking sound when at idle sometimes warm and cold, any ideas?
Does anybody have a write up and pics on how to change out the spark plugs? Thank you every one and happy motoring!

 

spark plugs are under that Jaguar Cover.. remove the coil on plug, remove spark plug, replace spark plug, replace coil on plug..

 

My machine has in intermittent tick which is noticed after a long run, and to best knowledge never upon start-up and takeoff. The mechanic could not readily ID the source of the sound, but offered to spend a few hours tracking it down. The tick is not a regular tick like that of a busted rocker arm of a loose rod big-end. I just returned from OKC in 40 degree temps and did not hear the tick, hence the intermittent nature of the noise. The car runs great, so I haven't been too worried about it. Is your tick a rhythmic sound or irregular? I didn't download the spellcheck because of the spyware deal, so I hope I didn't misspell rhythmic.