R56 Carbon Cleaning
Your R56 Mini Cooper S will need periodic cleaning of the intake valves. Due to the direct fuel injection, carbon builds up on the intake valves. Symptoms of this condition incude rough running when started up cold. It will get better after a minute or two. Also performance degrades slowly over time. You may not notice the decrease in performance since it happens gradually.
Here are the intake valves before cleaning. This Mini Cooper had 55,000 miles on it and has severe intake valve carbon buildup.
We are able to clean it without removing the cyinder head.
Here are the same intake valves after cleaning with the walnut shell blaster. Cold starting is great and performance has been restored.