The other day i was messing around with a bimmer on the highway i guess you can say i went higher then i normally go with the Rpms...around maybe 5000 or so...Anywas when i got home i heard a ticking noise while idleing...tick tick tick....and i know its not exhaust...because if i rev the motor up a little it goes away when the idle drops back down its there again...This did this once before then as suddenly as it came it went away but now its back again...any ideas on what it could be....? Oh yeah i noticed that i do use a little oil it was maybe a half a qt low after that freeway run...now its full again i added some last nite but the tick is still there....sounds like its coming from the valve covers.....you can hear it in the exhaust too...but like i said i know its not an exhaust leak because this noise was there a month back then it was gone now back again....Thanks...........