CP4 0445010508 Fuel Injection Pump – Bosch Compatible for Audi & Volkswagen 2.0L TDI Diesel Vehicles | Rsolid Engine Parts
Modern 2.0L TDI engines from the Volkswagen Group demand precise, high-pressure fuel delivery. The CP4 0445010508 high-pressure fuel injection pump – fully compatible with Bosch CP4.1 architecture – is the direct replacement for many Audi and VW models equipped with common rail diesel systems (EA288, EA189). Whether you own an Audi A4, VW Passat, or a Tiguan, this pump restores factory performance, improves cold start behavior, and ensures reliable rail pressure under hard acceleration. Rsolid engine parts supplies this critical component with rigorous bench testing and a 12-month warranty.
1. Structural Advantages of the CP4 0445010508 Injection Pump
The Bosch CP4.1 pump is a compact, high‑efficiency design specifically developed for passenger car diesel engines. The 0445010508 variant matches OEM specifications with the following engineering strengths:
Two‑Plunger Radial Piston Design – Two opposing plungers driven by a single eccentric cam deliver a continuous, high‑volume fuel flow with minimal pulsation, ensuring stable rail pressure even at low engine speeds.
High‑Pressure Fuel Lubrication – All internal moving parts (plungers, cam, roller shoes) are lubricated and cooled solely by diesel fuel, eliminating external oil lines and simplifying installation.
Integrated Digital Flow Control Valve (ZME) – Electronically controlled by the engine ECU to meter the exact fuel quantity entering the pump. This reduces fuel consumption, lowers combustion noise, and helps meet Euro 5/6 emissions standards.
Compact Die‑Cast Aluminum Housing – Lightweight yet strong, with internal pressure relief channels that prevent cavitation during cold starts.
Direct Bosch Compatibility – Identical mounting flange, drive coupler interface (triangular or splined), high‑pressure outlet, and electrical connector as the original Bosch 0445010508. No adapters or software modifications needed.
2. Compatible Audi & Volkswagen Models (≤5)
This pump is specifically calibrated for 2.0L TDI common rail engines (EA189 and EA288 families). Common applications include:
Audi A4 / A5 2.0 TDI (2008–2015, engine code CAGA, CAHA, CJCD)
Audi Q5 2.0 TDI (2009–2016, CJCA, CNHB)
Volkswagen Passat / Passat CC 2.0 TDI (2008–2014, CBBB, CBAB, CFGB)
Volkswagen Golf / Jetta 2.0 TDI (2009–2014, CBAA, CBAB, CJAA)
Volkswagen Tiguan 2.0 TDI (2008–2016, CFFA, CFGB)
⚠️ Always verify your engine code and original Bosch pump number. The 0445010508 is often stamped on the pump body near the high‑pressure outlet.
3. Common Failures & Installation/Replacement Advice
Typical Symptoms of a Failing CP4 0445010508 Pump:
Extended cranking time before start – Especially after the vehicle sits overnight.
Loss of power / limp mode – Often accompanied by DTCs P0087 (rail pressure too low) or P0191 (fuel pressure sensor rationality).
Metal particles in the fuel filter housing – The CP4 pump is notorious for internal wear that produces fine ferromagnetic debris.
Rough idle or intermittent stalling – Worse when the fuel tank is below ¼ full.
Unusual noise from the pump area – Metallic whining or clicking that changes with engine RPM.
Professional Installation & Replacement Recommendations:
Never replace just the pump – If the old pump has failed internally, the entire fuel system is contaminated. Replace the pump, rail pressure control valve, and all six injectors, or risk immediate re‑failure.
Perform a full system flush – Remove and professionally clean the fuel tank, supply and return lines, and fuel cooler (if equipped). Install a new fuel filter module and consider an auxiliary magnetic filter.
Use VCDS (Vag‑Com) or dealer‑level diagnostics – After installation, clear learned fuel trim adaptations and perform a “high‑pressure pump adaptation” routine.
Prime the low‑pressure circuit – Before starting, use a vacuum primer to pull fuel through the filter and pump return line until no air bubbles appear. CP4 pumps are extremely sensitive to aeration.
Fill the pump with diesel assembly lubricant – Remove the outlet fitting and pour clean diesel or Bosch special lubricant into the pump housing to prevent dry start scoring.
Torque high‑pressure connections precisely – The M14 × 1.5 cone seal outlet to the rail: 35–40 Nm. The low‑pressure inlet M16 × 1.5: 25 Nm.
Inspect the timing drive gear and belt – On EA189 engines, the pump is driven by a toothed belt. Replace the belt and tensioner if worn.
After installation, perform a leak test – Run the engine at idle and at 2,500 RPM, inspect all unions for wetness.
💡 Pro Tip: CP4 pump failures on 2.0 TDI engines often start with a clogged fuel filter (increased pressure drop) or water contamination. Always use OEM fuel filters and drain the water separator regularly.
4. Why Choose Rsolid Engine Parts?
Exact Bosch CP4.1 Compatibility – Direct replacement for Audi & VW 2.0 TDI without modification.
100% Calibration Tested – Every pump is run on a Bosch EPS 200 test bench to verify delivery volume, rail pressure control, and regulator response. Test report available upon request.
12‑Month Warranty – Full coverage against manufacturing defects.
Competitive Pricing for Workshops – Discounts for mechanics, garages, and fleet owners.
Fast Worldwide Shipping – Stock held in EU, US, and Asia warehouses for quick dispatch.
Direct Technical Support – Our diesel specialists help with fitment, VCDS coding, and troubleshooting.
Contact Rsolid Engine Parts Today
📞 WhatsApp: +8615975376778
📧 Email: amy@rinjector.com
