Post by
DFW2011M56S »
https://forums.nicoclub.com/dfw2011m56s-u266482.html
Thu Feb 20, 2020 6:42 pm
I started getting those codes on my 2011 M56S at about 85K. It was carbon buildup on the intake valves. I tied a couple of products that were supposed to get rid of it. It built up a very gummy deposit on the valves. I ended up yanking the intake and using a combination of B12, walnut shell media blasting and a small pick to remove it all. Took around 6 hours to do it all. I used a chemical cleaner into the pcv valve vacuum ports on the intake manifold every oil change after that. I had to change the starter solenoid at 140K. Valves were near spotless using the aerosal GDI valve cleaner every 5-6K.