I have a knocking noise on my 1996 chevy truck.
It does the knock when the truck is cold and goes away when its warmed up. I changed
the oil from a 5w-30 to a 10w-30 and it went away for a while and now it started back
up. The truck almost up to 180,000 miles on it . I'm using super tech oil and the oil filter
is a ac delco. I been told by people that it could be a piston slap,lifters or that i change
oil brand. It could be anything and really want to know what it is rather than hearing
from different mechanics saying its this and that. Please help!