SevereAffected: 2008-2015100,000–180,000 miles

Audi A4 B8 2.0 TDI 143bhp — Turbocharger Failure

Turbocharger failure on the B8 A4 TDI mirrors the wider VAG TDI pattern — oil sludge in the feed pipe causes bearing failure, often presenting as a sudden loss of boost.

Severity

Severe

DIY Difficulty

Hard

Est. Cost

£650–£1100

OBD Codes

P0299

Component Diagram

Turbo

Typical layout and location for the Turbo assembly.

Reference Illustration

Symptoms

Loud whining from turbo
Loss of power and boost
Blue smoke on acceleration
P0299 underboost

Root Cause

Oil sludge blocks the turbo oil feed. Long oil change intervals in company car use are the main contributing factor.

How To Fix

Check oil feed pipe
Remanufactured unit: £400-700
Flush oil system on installation
Fitted: £650-1,100

Estimated Repair Costs

Repair Option	Est. Cost (GBP)
DIY (parts only)	£260–£440
Independent Garage	£650–£1100
Main Dealership	£1040–£1760

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.