99% sure it's just valve clearance. If it was a "rod knock" you, and everyone near you, would know it by the noise it would produce. As everyone said, these engines are known for excessive valve clearance over time. From what I understand # 7 (back drivers side) is the worst. That's the one I can hear on mine. It's been that way since I bought it over a year ago. It doesn't bother me, I don't think it is doing any damage. (fingers crossed) If you do change the engine for some reason, stay with the same year and you wont have the wiring problems.

 

Thanks for all the help, im gonna turn it to a local shop and see whats up, im running 10w/30 as of now