Offroad-Express

Gidday,
When my ute is cold, it makes a slight chattering/ tapping noise. Its not a knocking sound, just a slight chatter. Clears up after about 30seconds/1min.
Im using castrol 15w-40. Is this something to do with the tappet adjustments or something??

Cheers

i would guess its more to do with lack of oil flow. 15w40 is going to be fairly thick and it will take a while to pump around the engine.
mine runs a whole lot better with a 5w-40 and i'm almost in winterless north!