Engine tick

[JLR4x4]

Hey guys, my dad has a 2004 1/2ton with a 5.7 hemi. I have noticed here lately on the driver side it has a tick in the engine, it is not loud but it is definitely "timed". The only time you really here is when you're at Idle, I just need to know if there is an issue with valvetrain that I might need to be aware of. I know a buddy of mine told me about the pushrods being too long in some engines , any ideas ? thanks. Also I checked and it doesn't appear to be coming from the exhaust manifold.

 

[MarkV]

I think that either the rockers or the lash adjusters can lock up in the 5.7 engines.... But i may be wrong.