2002 Sunfire Loud Knocking/Tapping Noise

There is a loud knocking/tapping noise coming from underneath the Cam cover. Gets louder as you rev it up. So far, the consensus has been a thrown rod, haven't taken it to the shop yet. Wanted to see if I could get an idea as to cost if it is a thrown rod, or other opinions of what could be causing it first. Thanks!

could be a collapsed lifter, cracked wrist pin, bad valve, bad valve spring, or a bad rocker arm. I just had my 2.4 LD9 replaced for the same problem.

that happened to me 2 times... the first time was because of a warped head and a few other problems... then it was the timing chain