I used synthetic oil for over 100 thousand miles. I was using the correct recommended oil weight for the vehicle but the synthetic oil is not thick enough to stay up in the valves therefore causing valve damage.

So after hearing lots of chatter from the valves and dry start-ups in the valves I tried LUCAS oil after the fellow at Advance Auto said that some engine builders won't crank an engine unless the engine has LUCAS in it. So after two quarts/ two-oil changes -NO MORE chatter when I start the engine or sit in idle. No $1,500.00 valve job and my gasoline engine does not have to sound like a diesel while idling. Thankyou LUCAS OIL.