Carbon buildup is a common issue on modern diesel engines, particularly vehicles that spend a lot of time driving around town or at lower engine speeds. Over time, deposits can build up in the intake system and around the intake valves, restricting airflow and affecting engine efficiency. This Holden Colorado 2.8L Turbo Diesel came into Revhigh for a carbon clean and walnut blast to remove years of built-up deposits. Just How Dirty Was It? As you can see from the photos, the