Hello and sorry for such a delay,
I'm sure you have checked the oil level, but i am required to ask :-)
Did this just come on all of a sudden?
Does it go away when engine rpm is increased?
Has anything been looked at yet?
if i increased the rpm the noise goes away its only in idle lifter noise
i replaced the oil filter and the oil,replaced pickup oil straining oil pump....i dont know if its a oil pump problem
The oil pump can be tested using a gauge attached to where the oil pressure switch is on the timing cover to verify pressure at idle. However, we see this quite often on these and being the lifters/tappets are hydraulic and not adjustable, there is not much to do other than testing the pump or replacing the lifters, but i wouldn't be too concerned if it is only at idle....