SevereAffected: 2008-2015100,000–200,000 miles

Audi A4 B8 2.0 TDI 143bhp — Injector Failure

High-mileage A4 B8 TDIs suffer injector wear, causing rough running, smoke and diesel contamination of engine oil.

Severity

Severe

DIY Difficulty

Professional Only

Est. Cost

£350–£1200

OBD Codes

P0201P0202

Component Diagram

Injectors

Typical layout and location for the Injectors assembly.

Reference Illustration

Symptoms

Rough idle and misfires
Hard cold starting
White smoke on startup
Oil level rising
P0201-P0204 codes

Root Cause

Common rail injectors wear over high mileage. Extended service intervals and contaminated fuel accelerate degradation.

How To Fix

Contribution test identifies worst injector
Ultrasonic clean and test before replacing
New injectors coded to ECU
Cost: £300-600 per injector fitted

Estimated Repair Costs

Repair Option	Est. Cost (GBP)
DIY (parts only)	£140–£480
Independent Garage	£350–£1200
Main Dealership	£560–£1920

Other Faults on This Variant

Timing Belt Failure

Critical

2008-2015100,000–140,000 miles£400–£700

The B8 A4 2.0 TDI uses a timing belt with a 140,000-mile service interval. Many specialists recommend 100,000 miles. Belt failure is catastrophic on this interference engine.

EGR Cooler Failure and Coolant Loss

Severe

2008-201570,000–140,000 miles£500–£900

EGR cooler failure is common on the B8 A4 TDI. Internal corrosion allows coolant to leak into the intake — initially causing rough running and white smoke.

DPF Blockage

Moderate

2008-201540,000–90,000 miles£200–£1400

The A4 B8 TDI is frequently used as a company car on short local journeys rather than motorway runs. DPF blockage is the most common ownership complaint.

Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.