Vauxhall Astra Astra H 1.7 CDTi 100bhp — Injector Failure and Hard Starting
Injector failure on the Z17DTH engine causes misfires, rough running and in advanced cases prevents starting. The solenoid-type injectors used in this engine respond well to professional cleaning.
Severity
SevereDIY Difficulty
Professional Only
Est. Cost
£250–£800
OBD Codes
P0201P0202P0263Injectors
Typical layout and location for the Injectors assembly.
Symptoms
- Rough idle and vibration
- Hard cold starting
- White smoke on startup
- Loss of power at high RPM
- P0201-P0204 codes
Root Cause
Solenoid injectors wear at their internal control valve and needle seat. Contaminated fuel or extended service intervals accelerate deterioration. Each injector has a calibration code.
How To Fix
- Contribution test to identify failing cylinder
- Remove and send for ultrasonic cleaning and test — often restores function
- Replacement injectors must be coded to ECU
- Cost: £150-400 per injector fitted
Estimated Repair Costs
| Repair Option | Est. Cost (GBP) |
|---|---|
| DIY (parts only) | £100–£320 |
| Independent Garage | £250–£800 |
| Main Dealership | £400–£1280 |
Other Faults on This Variant
EGR Valve Failure
ModerateThe Isuzu-sourced Z17DTH and Z17DTJ engines in the Astra H have a well-documented EGR valve failure. Carbon deposits cause the valve to stick, resulting in power loss and increased emissions.
DPF Blockage
ModerateDPF-equipped Astra H 1.7 CDTi models (post-2007) suffer from the same DPF blockage issues as most diesel Vauxhalls of this era. Urban use is the root cause.
Dual Mass Flywheel Failure
ModerateDMF wear on the Astra H 1.7 CDTi is a high-mileage inevitability. The flywheel's internal dampers lose effectiveness, causing vibration and judder that makes the car unpleasant to drive.
Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.