2006 Saturn Vue 3.5L Timing Belt noise

My 2006 Saturn Vue (170k+ mi.) runs super
strong and smooth. However, it makes a
knocking noise when first cranked but it
goes away after the oil pressure builds. I've
been told there is an arm or lever that rises
with the oil pressure that is related to or a
component of the timing belt and mine is
sticking down until oil pressure Max is
reached. If I start the car and let it idle or
"warm up" for 10 mins or so it runs like a top
with no noise at all but if I don't give it time
and drive off immediately it makes a heck of
a racket going down the road for a bit and
eventually goes away. Do I need to change
the timing belt or someone suggested
running straight 30 weight oil and that would
take care of the problem? What are my
options and the what is the severity of this
knocking.