Vauxhall Astra Astra H 1.7 CDTi 100bhp — DPF Blockage
DPF-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.
Severity
ModerateDIY Difficulty
Moderate
Est. Cost
£200–£800
OBD Codes
P2452P2453DPF
Typical layout and location for the DPF assembly.
Symptoms
- DPF warning light illuminated
- Reduced performance
- P2452, P2453 codes
- Excessive black smoke
Root Cause
Short cold trips in urban environments prevent the DPF from reaching regeneration temperature. The 1.7 CDTi's smaller displacement means it takes longer to generate sufficient exhaust heat.
How To Fix
- Attempt passive regen with a 30-min motorway run
- Forced regen via diagnostic tool if passive fails
- Professional DPF clean: £200-300
- Replacement if physically damaged: £400-800
Estimated Repair Costs
| Repair Option | Est. Cost (GBP) |
|---|---|
| DIY (parts only) | £80–£320 |
| Independent Garage | £200–£800 |
| Main Dealership | £320–£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.
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.
Injector Failure and Hard Starting
SevereInjector 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.
Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.