I've read a lot of the posts about the various ticking noises caused by lifters and pistons and all the different things people have tried. I see a lot of people say to change your oil weight and filter type. Does anyone know how the K&N compares to the purolator? Mine only does it a low rpm and not all the time. The exhaust was just recently inspected so I don't think it's a crack in the manifold. I'm not a mechanic by no means but if it is a crack in the manifold where does it usually occur (pic please)? I'm sure I sound like a newby cause I am. Thanks for any help any of you true mechanics might have for me.