Greetings to all,

I am new here so please forgive me if I mess up something lol. My son has a 2003 intrepid with a 2.7 and it has 75k miles. it was his grandmothers. recently he has had a ticking, and it has gotten louder and louder. we were thinking collapsed lifter or clogged oil port. we pulled the intake Plen, valve covers off and cranked the engine, oil on all lobes and chain. but we did notice 2 of the lobes have a white mark and one has a flat spot.
so question is/are
- can a flat spot on a lobe cause a loud ticking
- can a flat spot cause a misfire? (i felt it "ping" through the gas peddle)
- how can I tell without removing the cam if i have a collapsed lifter.

Attaching some pics and thank you to everybody!!

 

after inspecting it, we pulled the plugs and did a compression test,,, 185 -165 was the range, (165 was on #6). but halfway through our testing, the oil cup in the head started to actually pump oil high out! the other cup, really nothing. so we put a wire in, and now it is pumping out out. I think we are clogged up! we are still thinking of replacing the exhaust cam on the right side though as it does has a flat, crush spot. then flush the engine well,, twice! and run synthetic after that and see how it goes. chains are good and tight, lifters look good, oil is flowing onto each lobe and from the ends of the cams. all the injectors are clean and at 12.2 ohms.