N47/N57 CP4 Metering Valve Bypass Kit

For those that don’t know, the CP4 is the fuel injection pump that is installed on the second generation USA BMW diesels with the N47 and N57 engines. This injection pump uses only its fuel supply for lubrication, diesel first flows into the bottom end of the pump to lubricate the camshaft, rollers, lifters, and bushings before the diesel flows up to the metering valve to be used for injection. Unfortunately, the CP4 can be rather sensitive to fuel quality. If contamination occurs and one of the rollers gets stuck, the pump will start making metal shavings in the bottom end. As the CP4 continues to pump, it is now pumping diesel contaminated with metal shavings through the metering valve and into the rest of the injection system. When this failure occurs the CP4, injectors, fuel rails, rail pressure sensor, pressure control valve, high pressure lines, injector return lines, tank lines, and fuel module will all need to be replaced. This kit doesn’t prevent a failure from happening but it does isolate the CP4s lubrication supply from the injection fuel supply and prevents all the other components in the injection system from being damaged. Because of how the metering valve is isolated and given its own supply with this kit, now in the event of a failure only the CP4 and return filter will need to be replaced. 

The 10 micron fuel filter included with the kit also contains a neodymium ring magnet on the outlet side of the element to help further catch any fine metallic particles. 

The block only option is just the block, o rings, and hold down bolts for those who wish to source their own ancillary parts. 

Install video courtesy of Motorsport Inspired

Install video courtesy of Brad Tourt 

Written install courtesy of SSK Side Shop Kreationz