Lash eliminator question.

[miles davis]

I have a top end noise in my 4 valve 4.6 MKVIII that I think is a lash eliminator and a bad
secondary chain tensioner. My question is once I get the front cover and the valve
covers off how do I check the lash eliminators with out pulling them all and doining
a leak down test on them ?

I know these motors are built tight and I run 5-30 synthetic.
Would a thicker oil like 10-30 help ?

Thanks