Animal323

I have this sound coming from the motor that started off light, went away and now its back and louder then before. It makes a light tick tick tick sound at idle but then gets increasingly louder when im in gear. Its loudest in 2nd gear. I heard from a friend it could be a valve tap. If it was what would i have to do just tighten it or replace it? It sounds like something it slapping or rattling. I no its a problem because i dont listen to the radio when i drive i listen to the car and i no for a fact it never made that sound till this past week and half. I say this because ive heard from someone that the ls1's always makes some sort of sound. By the way the oil level is fine and it was changed less then 300 miles ago. Anyone have any ideas?