Ask the Expert: What steps can technicians take to remove soft carbon and/or hard carbon deposits in GDI-equipped vehicles?

Q: What steps can technicians take to remove soft carbon and/or hard carbon?

A: Soft carbon can be addressed by following the manufacturer’s preventative maintenance schedule along with a fuel additive that may be added to the vehicle’s fuel system before warm up. The technician can also utilize a fogger system via the throttle body. The fogger is connected to a pressurized dispenser filled with a chemical blend formulated to dissolve baked-on carbon deposits from the valves and passageways.

For hard carbon, the process is more involved. The most common procedures call for removing the intake manifold to expose the head’s ports, and rotating the engine by hand in its normal direction of rotation so that the intake valves for one of the cylinders are completely closed, then utilizing some form of media blasting.

Information provided by: Robert Bosch LLC