What is a Piezo injector?
A piezo injector is a Common Rail diesel fuel injector that uses a piezo crystal stack instead of a magnetic solenoid to open the nozzle needle. It acts up to five times faster than conventional injectors, allowing for 6-10 precise injections per cycle to improve efficiency and reduce emissions
Bosch Piezo Injectors
Piezo injectors made by Bosch run at pressure levels between 2,000 bar and 2,700 bar. Their engineering promotes optimal fuel atomization, which translates to improved fuel combustion and engine efficiency. They are used for the premium car segment and in light duty vehicles.
Pros of Piezo Injectors
Precision & Efficiency: Piezo injectors allow for extremely small pre-injection quantities and more precise fuel metering, which reduces fuel consumption and CO₂ emissions.
Reduced Noise: Because they can deliver fuel in multiple small bursts, they significantly reduce “diesel knock,” resulting in a quieter engine.
Compact Design: Since the actuator is integrated into the housing, these injectors are slimmer than solenoid models and require less installation space
Cons of Piezo Injectors
- Failure: The internal piezo crystal stack can fail, causing intermittent or no spray.
- Leakage: Contamination can lead to internal, constant leakage into the cylinder.
- Coding: Requires coding to the Engine Control Unit (ECU) during replacement
- Limited parts availability: Some key replacement parts are not yet available to the aftermarket making repair unlikely and brand new units can be expensive.
Reconditioning a Bosch piezo injector nozzle requires high-precision, specialized tools to disassemble and reassemble the injector in a clean environment, ideally under oil to prevent air bubbles.
- Preparation: Clean the work area thoroughly. Use plugs to cover the inlet and back leakage connections to prevent contamination.
- Disassembly: Fix the injector in a specialized fixture. Remove the nozzle nut and carefully remove the nozzle, needle, spacer, and spring. 50D079, 50D091
- Recharge with Oil: The hydraulic amplifier must be recharged with ISO test oil during reassembly to ensure proper operation, a crucial step to avoid zero fuel flow. 50D0659
- Assembly: Assemble the new components in the correct order: shim, spring, and bushing CMR66 & CMR665
Piezo injectors are highly sensitive; if the internal parts are disturbed the injector usually requires calibration on a test bench to generate a new IMA (Injector Measurement Adjustment) code for the vehicle’s ECU
- Tightening: Install the nozzle nut and tighten it – 18D36, 18D37 & 18D38
- Testing: After assembly, the injector must be tested on a specialized test bench to verify correct operation and spray patterns
- Adjustment Shims: Fuel delivery is adjusted using regulation shims on the nozzle needle. Changing a shim by just 0.1mm can cause a significant increase or decrease in fuel quantity.
Finally replace the copper washer before refitting into the engine –
F00VC17504 = 27D152
F00VC17503 = 27D145
F00VP01004 = 27D136
F00VP01008 = 27D185
Replacement Bosch Nozzles, Injector and Vehicle Info Below…
| DARWEN NOZZLE NUMBER | BOSCH NOZZLE NUMBER | INJECTOR NUMBER | VEHICLE APPLICATION |
| PEF02R | F00VX30002 | 0445115007, 0986435350, 0986435426 | Renault Espace, Laguna 2,0 DCi-Koleos |
| PEF05AW | F00VX30005 | 0445115037 * can also use PEF22 | VW/AUDI 3.0 ltr |
| PEF07 | F00VX30007 | 0445115008, 0445115009, 0986435354, 0986435421, 0445115048, 0445115070 | BMW 2.0 |
| PEF10 | F00VX20010 | 0445115005, 0445115006, 0445115016, 0445115017, 0445115026, 0445115027, 0445115063, 0445115064, 0445115071, 0445115072, 0445115075, 0445115076, 0986435355 | Mercedes Benz C 320 CDI, CLK 320 CDI, E 280 320 CDI, G 320 CDI, GL 320 CDI, ML 280 300 320 350 CDI, R 280 300 CDI, S 320 CDI 3.0D |
| PEF14+ | F00VX40014 | 0445115028, 0445115029, 0986435352 | VW Crafter 2,5l |
| PEF17 | F00VX20017 | 0445115032, 0445115033, 0445115068, 0445115069, 0445115073, 0445115074, 0986435356, 0445115069, | Mercedes Sprinter 2,2 CDI (2148cm3, R4, OM646), Vito 2,2 CDI, Viano 2.2 CDI |
| PEF20 | F00VX40020 | 0445115042, 0445115091 | Citroen, Peugeot, Land Rover |
| PEF21 | F00VX40021 | 0445115077, 0445115050, 0986435359 | BMW 3 (E90), 3 (E91), 3 (E92), 3 (E93), X3 (E83), X5 (E70), X6 (E71, E72) 3.0D 12.04-12.13 |
| PEF22 | F00VX40022 | 0445115052, 0445115078, 0986435358* can also use PEF05AW | Audi A3 A5 A6 A7 A8 Q7 3.0 TDI V6 |
| PEF26 | F00VX30026 | 0445116001 | BMW 120, 320, 520, X3 2,0D |
| PEF29 | F00VX40029 | 0445116004, 0445116005, 0445116029, 0445116030, 0445116034, 0986435360 | AUDI A3, A4 – 2.0 TDI, VW GOLF, PASSAT 2.0 TDI |
| PEF30 | F00VX40030 | 0445116007, 044511608, 0445116015, 0445116023, 0445116022, 0445116014, 0445116047, 0986435357, 0986435379 | VW – Touareg 3.0, AUDI A4 – A6 2.7 -3.0 TDI |
| PEF39 | F00VX40039 | 0445117020 | AUDI Q7, VW TUAREG, PORSCHE 4,2L 2009 |
| PEF40 | F00VX30040 | 0445116056, 0445116006, 0986435443 | Honda Accord, Civic, CR-V 2.2d |
| PEF41 | F00VX30041 | 0445116024 | BMW 120, 320, 325, 330, 520, 525, 530, 740, X1, X3, X5, X6, 2.0 d, 3.0 d |
| PEF42 | F00VX40042 | 0445116012, 0445116013, 0445116064, 0445116065, 0986435403 | Citroen, Peugeot, Land Rover, Jaguar 3.0D |
| PEF43 | F00VX40043 | 0445116025, 0445116026, 0986435404 | Mercedes C350, CLS350, E300, E350, GL320, GL350, GLK3350, ML300, ML350, R300, R350, S350, Viano, Vito 3.0d |
| PEF48 | F00VX20048 | 0445116028, 0445116027 | Mercedes-Benz 219, 319, 419, 519 CDI Sprinter II 184KM, 190KM, 3.0l (2009-) |
| PEF54 | F00VX20054 | 0445116019, 0445116059, 0986435395 | Fiat Ducato, Iveco 3.0l |
| PEF60 | F00VX40060 | 0445117015, 0445117016, 0445117023, 0445117096, 0986435415 | Ford F250. 350 6,7l 2011-2016 |
| PEF61 | F00VX40061 | 0445116017, 0445116018 | HYUNDAI SANTAFE. IX35. KIA CARNIVAL. SORENTO. SPORTAGE |
| PEF65 | F00VX40065 | 0445116039, 0445116040, 0445116072, 0986435422 | AUDI A4-A8 Q7 3.0 TDI, PORSCHE Cayenne Panamera 3.0, VOLKSWAGEN Touareg 3.0 TDI |
| PEF75 | F00VX40075 | 0445117026, 0445117027, 0445117075 | AUDI A4, A5, A6, A7, A8, VW TOUAREG 3.0L |
| PEF78 | F00VX40078 | 0445117028, 0445117029, 0445117070, 0986435431 | Audi 313HP Biturbo, A6, A7, Q5, Porsche Panamera, Volkswagen, 3.0 TDI (2009 – 2019) 3.0d |
| PEF80 | F00VX40080 | 0445116066, 0445116050 | LAND ROVER Discovery IV 3.0l SDV6 AWD,180kW-200kW,2010-2017, LAND ROVER Range Rover IV 3.0l SDV6 Hybrid AWD,215kW-250kW,2013-2017, LAND ROVER Range Rover Sport II 3.0l SDV6 Hybrid AWD, 215kW-260kW,2013-2020 |
| PEF85 | F00VX30085 | 0445118035 | BMW 750, X5, X6, M, 3,0L, 2012-2018 |
| PEF91 | F00VX40091 | 0445117034, 0445117035, 0986435428, 0986435444 | Mercedes Benz A-Class, B-Class, C-Class 2,2l (2007 – 2017) |
