http://imgur.com/DTW1zaN.jpg

He ran it low on oil (leaking from improperly sealed oil filter) a few months ago and got some
shim ticking, but it went away when oil is added. it has a tiny residual
sound that can be heard through the right hand wheelwell (injectors are louder than it) he is concerned for the engines health, I told him I would
confer with the Jag Forums. What do you guys think?

(02 XJR 120k)

 

Hard to see from the pic-the cam cover really needs to come off for a better view. A very tiny residual ticking is probably not a major cause for concern. Use a 10W/40 oil & keep the level right at the maximum-these engines don't like running low on oil, & in extreme cases of oil starvation can spin a big-end bearing on number 1 cylinder.

The dipstick & sump capacity was altered during the vehicle's production run, so the best bet is to keep the oil level right at the maximum & even slightly over by up to 0.5L. My XJR runs quieter with the oil level right at the maximum & slightly above-it also allows for any oil useage by the engine which could drop the oil level anyway over time & mileage between services.

I wouldn't worry too much about the noise if it's just a residual tap-just keep an eye (or ear!!!) on it over the next few weeks. Any other course of action will require money to be spent & parts to be replaced