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
SevereDIY Difficulty
Hard
Est. Cost
£650–£1100
OBD Codes
P0299Wheel Bearing
Typical layout and location for the Wheel Bearing assembly.
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
CriticalThe 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
SevereEGR 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
ModerateThe 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.