CP4 is the fuel injection pump that is installed on the second generation 3.0 TDIs and 2.0L TDIs, plus almost any  common rail engine that uses the cp4 pump.

The Bosch CP4 high pressure pump is used on several car brands, especially common rail diesel engines. This pump has been used on a wide range of vehicles manufactured by various brands, mainly between 2007 and 2020. Among the car brands on which the Bosch CP4 pump can be found are:

1. Volkswagen Group (VW, Audi, Seat, Skoda)

• VW Passat, Golf, Touareg
• Audi A4, A6, Q7
• Skoda Superb, Octavia
• Seat Leon, Exeo

2. BMW

• Models equipped with 2.0 and 3.0 liter diesel engines.

3. Ford

• Ford F-250, F-350 and other models equipped with Power Stroke engines (mostly in the US).

4. General Motors (Chevrolet, GMC)

• Models equipped with the Duramax engine (mostly trucks, such as the Chevrolet Silverado and GMC Sierra).

5. Mercedes-Benz

• Diesel engines, including C, E and ML class models.

6. Jeep

• Jeep Grand Cherokee equipped with a diesel engine.

7. Fiat

• Models equipped with JTD/MultiJet diesel 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. This kit will fit TDI equipped vehicles with the CPNB, CNRA, CNRB, CATA, CBEA, CJAA, CKRA , CUAA , CAGA, CAHA and many other engine codes. No tune is required for proper operation, also works with vehicles that have already been tuned.

The kit includes all the bits and pieces necesary to be mounted, orings, pipe lines, filter and the adapter and is a 15 minutes job. If you are handy enough you can mount it without a mecanic. The adapter flange is made out of alu7075 a very strong material resistant at high temperatures and pressures. The part is built with a precision of 0,01 mm and respects all the factory dimensions and tolerances.