Cranks but won't start

It turns over but won’t start. also makes a metallic sound it didn’t do before while cranking.I changed battery a week ago and replaced air filter right before this started.Is it related or could it still be the starter even thou it’s turning?

If it’s turning over it’s NOT the battery. The metallic sound might be the starter (bendix).

If it’s not starting…check spark…then fuel…if those are fine…then it could be the timing.