[Gearhead999]

Valve noise is a mechanical sound that usually comes from too much valve clearance. It is a steady "clicking" and can be heard more at lower RPM's.

"Pinging" on the other hand is also known as "Spark Knock". Which is the fuel/air charge in the combustion chamber firing off before the spark plug fires. It sounds more like marbles rattling around, and comes when the engine is loaded. Like when you said, "Valves, when in gear and slamming on the gas". That sounds more like preignition, "Pinging". Oil weight, make, etc. isn't going to effect that.

Lighter oil in the winter is so the engine will turn over easier in the AM. Depending on where you live and how low the temperture gets will determine that.

For instance, here in Orlando, FL we don't worry much about that. Usually doesn't get cold enough to effect the starting.