My 1994 XJ has started putting out a fair amount of bluish smoke when driving slowly or idling. I suppose it does when on the highway but I just can't see it. However I'm not so sure about that because if I drive on the highway and jump off an exit it doesnt seem to start smoking a lot again until I've gone slow awhile or stopped at a light. Anyway I'm sure it's burning oil as I loose oil and it's not leaking and it smells like buring oil.
I guess my question is..Since it idles smoothly and has lots of power and seems to have no driving problems other than blowing smoke is it possible there is another cause short of rings/pistons? I was under the impression if it was valves it wouldnt smoke constantly. Any input is welcome.

My 1993 sport hit 24500 and started that, idle was perfect ran good with just a small knock in the morning or when above 4000 rpm but when I sat in a drive through or at a light too long it would smoke like a old diesel. I put up with it for about 20000 more miles and a lot of trying to make it go away. But I ended up putting a new motor in back in march. No smoke and plenty of power now. Towards the end I was using a quart for every 100 miles I drove, when I pulled it out and checked everything out it ended up being my cylinder walls had egg shaped out at the bottom enough too scrape oil on the downstroke and burn it at the top along with my valve seals and probrably the guides. Still not too bad for the mileage.