PORSCHE Panamera with nasty carbon build up on all intake valves | What is the solution?

About Porsche Panamera

The Porsche Panamera is a mid- to full-sized luxury car (E-segment or F-segment for LWB in Europe) manufactured and marketed by German automobile manufacturer Porsche. It currently spans across three generations, using a front-engine and rear- or all-wheel drive configuration. The Panamera debuted at the 13th Auto Shanghai International Automobile Show in April 2009, later launching hybrid and diesel versions in 2011. In April 2013, the company introduced a facelifted model, again at the Shangha...