Ford Focus Mk2 1.6 TDCi 110bhp — Injector Seal Failure and Diesel Weeping
The copper seating washers and O-ring seals on the 1.6 TDCi injectors harden with heat cycling and allow diesel to weep past the injector body. This causes a fuel smell and carbon build-up around the injector tops.
Severity
ModerateDIY Difficulty
Hard
Est. Cost
£150–£300
OBD Codes
None
Carbon Build Up
Typical layout and location for the Carbon Build Up assembly.
Symptoms
- Diesel smell in engine bay after running
- Carbon deposits around injector bodies
- Slight fuel weep visible at injector base
- Rough running if leak is significant
- Loss of injector clamping pressure
Root Cause
The copper crush washers and rubber O-rings that seal the injectors against the head degrade with repeated heat cycles. Diesel weeps past the failing seal, carbonises, and eventually allows unmetered fuel into the combustion chamber.
How To Fix
- Inspect injector tops — black carbonised residue confirms the leak
- Remove injectors, clean bores, fit new copper washers and O-rings (£5-15 per set)
- Re-torque injector clamps to spec
- Full job at indie: £150-300 depending on how many injectors need resealing
Estimated Repair Costs
| Repair Option | Est. Cost (GBP) |
|---|---|
| DIY (parts only) | £60–£120 |
| Independent Garage | £150–£300 |
| Main Dealership | £240–£480 |
Other Faults on This Variant
EGR Valve Failure
ModerateThe EGR valve is a common failure on the 1.6 TDCi engine, causing power loss, rough idle, and excessive smoke.
Dual Mass Flywheel (DMF) Failure
SevereDMF failure is one of the most expensive known faults on the 1.6 TDCi. Typically requires replacement of flywheel and clutch together.
Turbocharger Failure
SevereTurbo failure on the 1.6 TDCi is common at higher mileages, often caused by oil starvation or sludge blockage.
Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.