Ticking noise... I hear it on my engine too. I believe it's the lifters/vaulves, which are hydrolically adjusted. I was very concerned when I first heard the noise so I did a search here on the site... i forget exactlly what I read but it was convincing enough for me not to worry about it any longer.
Your oil is going somewhere, either into your coolant, out your exshaust or leaking out of the engine. First thing to look at is your coolant resivior. If there is oil mixed with your coolant then start thinking about a new head gasket. Second thing you can do is pull your spark plugs (the eyes of your engine) and have a close look at 'em. Oil on the plug(s) means valve guide seals. And the last item to check is the engine itself. Oil leaking from a damaged/old gasket will leave streaks.
I had the same problem with oil consumption a year ago. I ended up doing a search in the tech forum and found a wealth of troubleshooting info, but be forewarned, you need to set aside a couple of hours to get throught all the info in the posts. Hope this gives you abit of an idea on where to start. Keep us informed on what you find.
Cheers for now