Citroen C4 9HM Injectors

Citroen C4 9HM Overview

The Citroen C4 with the 9HM 1.6L HDi/TDCi engine was produced between 2007 and 2014. This vehicle uses Bosch common rail diesel injectors (primary part number 0445110340) operating at fuel pressures up to 2000 bar. The 9HM engine in the Citroen C4 produces and of torque. When replacing injectors on the Citroen C4 9HM, always use new copper sealing washers and torque to manufacturer specifications. Each injector should be coded to the ECU after fitting.

Compatible Injectors

Common Injector Problems in Citroen C4

• •
  Rough idle and engine vibration — Worn injector nozzles cause uneven fuel spray, leading to rough idle at low RPM. Most noticeable when the engine is cold.
• •
  Excessive exhaust smoke — Black or blue-grey smoke on acceleration indicates poor fuel atomisation. This is often caused by carbon buildup on the injector nozzle tip.
• •
  Poor fuel economy — A worn or leaking injector delivers incorrect fuel quantities, reducing efficiency by 10–20% in severe cases.
• •
  Engine misfire under load — Intermittent misfires during acceleration suggest one or more injectors are failing to deliver the correct fuel pressure.
• •
  Difficult cold starting — Degraded injector nozzles struggle to atomise fuel at lower cranking pressures, causing extended crank times in cold weather.

Other Engine Codes for Citroen C4

Other 9HM Vehicles

Related Pages

Bosch 1.6L HDi/TDCi — browse compatible engines, vehicles, and injectors