Since the widespread adoption of common-rail direct injection in the late 1990s, the high-pressure fuel pump has become one of the most mechanically demanding components in a modern diesel or direct-injection petrol engine. Driven directly off the camshaft or timing chain, it pressurises fuel to between 1,500 and 2,500 bar for diesel applications and 150 to 350 bar for GDI petrol engines, enabling the precise metering and atomisation that common-rail injectors require. The internal plunger, barrel and delivery valve operate at tolerances measured in microns, making the pump sensitive to fuel quality and contamination. The most destructive failure mode is running the engine briefly with low or contaminated fuel: debris from a failing low-pressure pump or a contaminated filter passes through the high-pressure pump and scores the plunger surfaces, causing pressure loss, rough idle, hard starting and, in severe cases, metal debris entering the fuel rail and damaging the injectors. Bosch manufactures a substantial share of original-equipment high-pressure pumps across VAG, Mercedes-Benz and BMW platforms, and their replacement units are direct-fit using the OE reference for the specific engine code. Lucas also supplies across a range of European diesel platforms. Replacement is almost always a specialist operation requiring clean-room conditions.
High-pressure pumps are specified by engine code, not just model year — the same platform often uses different pump generations across production years. Use your VIN or the engine code stamped on the block to filter OE references on this page. The pump's mounting flange, drive type (single or double lobe cam), flow rate and maximum pressure are all engine-specific. If you are replacing after a failure, also check whether the failure has produced metal debris in the fuel rail — if so, the injectors and fuel rail pressure sensor may also need replacing.
New OEM pumps from Bosch or equivalent tier-one suppliers are manufactured to new-part tolerances and carry the full OE warranty. Remanufactured units — offered by suppliers such as Lucas or Remante — are stripped, cleaned, re-honed to specification and fitted with new seals and valves before testing. A quality remanufactured pump from a reputable supplier performs to OEM specification and is a legitimate choice for a cost-conscious repair. The risk with low-grade remanufactures is incomplete cleaning or worn barrel surfaces that have been polished rather than re-honed, leading to early pressure loss.
If the pump failed gradually due to normal wear or a lubricity issue, replacing only the pump is often sufficient provided the fuel system is flushed and the filter replaced. However, if the pump suffered a catastrophic seizure or plunger fracture, metal particles will have entered the fuel rail and common-rail injectors. In that case the injectors must be removed, inspected and cleaned or replaced — continuing to run contaminated injectors after fitting a new pump risks rapid re-failure and significantly higher repair costs. Fuel system flushing and a new fuel filter are mandatory alongside any pump replacement.
Early warning signs include extended cranking before the engine fires from cold, a rough or lumpy idle at low revs, and hesitation on acceleration that clears at higher engine speeds as rail pressure recovers. More advanced failure produces a noticeably rough idle at all temperatures, power loss, and in diesel applications a characteristic rattling from the injectors as rail pressure drops below the minimum threshold. A fuel system pressure test will typically show rail pressure building slowly or failing to hold — the definitive diagnostic for a worn high-pressure pump before committing to replacement.
Showing 100 of 3,180 High-pressure Pump OE numbers. Enter the OE on the main OE search to jump to any reference.
