Bosch 0445110391 Diesel Injector

On the Fiat / Opel 1.9 JTD / CDTi 150hp platform, a failing Bosch 0445110391 injector typically presents as: misfire or judder, often between 1,500–2,200 rpm; rough idle with the engine management light on; intermittent single-cylinder faults that come and go; limp mode / reduced power; black smoke under load.

When two or more of these appear together, suspect the injector before peripheral systems — a comparative leak-off test and live-data cylinder-balance review will isolate the failed unit without tear-down.

The documented failure modes on this platform are: injector wiring / connector faults logging single-cylinder circuit codes (a documented weak point on this engine — especially injector 3); injector back-leak beyond specification; nozzle wear causing over-fuelling and smoke.

Internal wear cannot be repaired in situ — once delivery drifts outside calibration, remanufacture or replacement is the reliable fix.

On a single-cylinder circuit code, inspect the injector plug and loom first — wiring faults on this engine routinely mimic a failed injector. If several injector codes appear together, suspect a supply/loom or ECU driver fault rather than multiple simultaneous injector failures. Clear codes and confirm which returns first before replacing hardware. Run a comparative leak-off test to separate electrical from hydraulic faults.

Never condemn a common-rail injector on a fault code alone — codes identify the circuit or cylinder, while leak-off volumes and correction values identify the component.

Each remanufactured 0445110391 is fully stripped, ultrasonically cleaned and inspected; worn components are replaced with OE-grade parts. The rebuilt unit is then calibrated on a common-rail test bench against the manufacturer's specification sheet — delivery, back-leak and response are all verified before the injector is sealed and despatched with its calibration data on file.

Every unit carries a 12-month parts warranty and free UK delivery.

The 0445110391 trusted family covers 13 verified vehicle fitments across 4 makes: Alfa Romeo, Fiat, Saab and Vauxhall. Every fitment listed on this page is registry-verified — no scraped or assumed applications.

0445110391 supersedes or cross-references 11 further OE numbers, including 0986435208, 0445110243, 0986435104, 55196295, 55198218, 55221020, 71792979 and 71794089. Always match the reference etched on your failed unit's body — cross-references within a family are verified equivalents, but etched numbers remain the source of truth.