BMW N55 Basic Walnut Blasting Kit - 81292208037KT1

Direct injection has many advantages over port injection in terms of performance and efficiency. One area where direct injection engines have a problem however is the buildup of carbon in the cylinder head leading to the intake valves. This occurs due to blow-by from the crankcase being released into the intake manifold via the crankcase ventilation system. Over time this carbon builds up and starts to restrict the flow of air through the intake manifold and into the engine via the intake ports on the cylinder head.

Additionally, this carbon gums up the backside of the intake valves and valve stems. This buildup also has a negative effect on how air flows into the engine. In extreme cases, carbon buildup on the backside of the intake valves can cause the valve to no longer seat properly against the seat on the cylinder head.

The N55 is notably much better in reducing carbon build-up on the backside of the intake valves when compared to the N54 engine it replaced. Despite the improvements in crankcase ventilation carbon will still build up on the intake valves and runners on the N55 engine. This carbon will interrupt airflow into the engine and create adverse performance effects that can lead to various performance issues.

This kit is recommended for N55's with less than 100K miles or a car that has over 100K miles but has a newer valve cover. This kit allows for the valve cover to be left in place but does require the intake side ventilation ports to be blocked off so media does not get into the valve cover.