Since the transition from carburettors to direct and indirect injection, the injection nozzle has sat at the heart of the combustion process, metering precisely timed and pressurised pulses of fuel into each cylinder. In diesel engines the nozzle operates under extraordinarily high pressures โ common-rail systems routinely exceed 2,000 bar โ and the spray pattern geometry directly determines combustion efficiency, particulate emissions, and power output. Petrol direct injection nozzles operate at lower pressures but share the same fundamental vulnerability: contamination. Carbonisation on the nozzle tip is the dominant failure mode in both diesel and petrol applications, causing the spray pattern to distort from a finely atomised cone into a coarse stream that combusts unevenly. Drivers notice this first as rough running under load, increased exhaust smoke, and a measurable rise in fuel consumption. In diesel vehicles, hard starting in cold weather and white smoke on a warm engine are strong indicators. Bosch is the largest OEM supplier of injection equipment globally and covers the widest range of applications in this catalogue; Lucas holds significant coverage for French and British market vehicles. The OE reference is critical โ nozzle geometry, needle lift, and opening pressure are all chassis- and engine-specific values encoded in the part number.
The OE reference encodes not just the physical dimensions but the hydraulic calibration โ opening pressure and spray angle โ specific to your engine's combustion chamber design. Use your vehicle VIN or the make-model-year-engine selector to narrow results to your exact engine code, because the same model generation often uses different injection equipment across engine variants. The number is usually stamped on the nozzle holder body; matching it eliminates any risk of installing a nozzle with incorrect flow characteristics that would upset fuelling balance across all cylinders.
OEM nozzles from Bosch or Lucas are manufactured to the vehicle builder's hydraulic and geometric specification and carry the factory OE number. Quality aftermarket nozzles from reputable suppliers are flow-tested to the same opening-pressure tolerance and provide equivalent longevity when installed with clean fuel. Counterfeit or unverified nozzles are a known problem in the injection market โ they may appear dimensionally identical but use inferior needle and seat materials that erode quickly under high-pressure operation, leading to fuel leakage past the seat and elevated particulate emissions.
Yes โ in virtually every case, if one nozzle has failed due to wear or carbonisation, the remaining cylinders have run the same fuel and accumulated similar hours. Replacing a single nozzle while leaving worn units in adjacent cylinders results in a fuelling imbalance that causes rough running and uneven power delivery. The labour cost of a multi-nozzle diesel job is substantial, so it is economically rational to replace the complete set in one service visit rather than returning within a year for the remaining cylinders.
Diesel engines signal nozzle problems through hard cold starts, visible white or grey smoke on a warm engine, a misfire-like rough idle, and a distinctive 'diesel knock' that changes character when individual cylinders are cut out during diagnosis. Fuel consumption rises noticeably. Petrol direct injection engines show similar symptoms plus increased intake valve carbonisation because the cleaning effect of port injection is absent. A compression test or cylinder balance test on a diagnostic scanner will isolate the affected cylinder, and a nozzle pop-tester confirms whether the opening pressure and spray pattern are within specification.
Showing 100 of 4,827 Injection Nozzle OE numbers. Enter the OE on the main OE search to jump to any reference.
