I have a 2004 dodge caravan with the 2.4L DOHC.

Saturday we were driving at highway speed when we noticed the engine began to make a metallic ticking noise thay adjusted with RPM. It seems to get worse up until about 40-50 mph, then smoothes out until downshift.

When we got to our destination I started doing some diagnostics and found it was dry of oil. I immediately thought we burned up a rocker or lifter. I added some 3 quarts of oil plus one quart of engine treatment to break up any sludge or carborization that may have occurred. No improvement.

Today I took the valve cover off and did some visual inspection. There's some wear on the cam lobes where hard particles have gone through, but over all everything looks clean.

My next assumption is to check valve lash to see if anything is worn or broken.

I have a few questions:

1. Does anything have thoughts/ideas where to look next, or what the issues may be?

2. What is the valve lash spec for stock hardware?

Any thoughts would be appreciated. Thank you in advance.