TonyDtorch said:the old school way of de-carbonizing an engine was to spray water down the air intake while it's running at 3k rpm...it was rather brutal but it worked.
John From Detroit said:A 2008 should not ping.. It has sensors that should adjust the timing to keep it from Pinging.
That said. they still can if run hot and heavy and/or with cheap gas.
Unless you are comfortable working on 21st Century Gas engines. I'd seek professional help (Mechanic skilled in that make).