CKFCar Known Faults
ModerateAffected: 2004-201060,000–110,000 miles

Vauxhall Astra Astra H 1.7 CDTi 100bhp — Glow Plug Failure / Snapping in Head

Diesel glow plugs burn out over time causing cold starting issues. The major problem is they often snap in the cylinder head when mechanics try to remove them.

Severity

Moderate

DIY Difficulty

Moderate

Est. Cost

£100–£300

OBD Codes

P0380
Component Diagram

Injectors

Typical layout and location for the Injectors assembly.

Injectors diagram
Reference Illustration

Symptoms

  • Hard starting in cold weather (below 5°C)
  • White smoke on cold start for 30 seconds
  • Flashing coil light or EML on dash

Root Cause

Carbon buildup around the tip of the glow plug effectively welds it into the cylinder head. Applying too much torque to remove it shears the threaded top off.

How To Fix

  1. Soak the glow plugs in penetrating oil for several days before attempting removal.
  2. Only attempt removal with the engine piping hot.
  3. If a plug snaps, specialist removal tools are required (£150-300 call-out fee).
  4. Standard replacement cost: £100-200

Estimated Repair Costs

Repair OptionEst. Cost (GBP)
DIY (parts only)£40–£120
Independent Garage£100–£300
Main Dealership£160–£480

Other Faults on This Variant

EGR Valve Failure

Moderate
2004-201050,000–100,000 miles£80–£350

The 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

Moderate
2007-201040,000–90,000 miles£200–£800

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.

Dual Mass Flywheel Failure

Moderate
2004-201080,000–150,000 miles£650–£1000

DMF 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.