Audi, A6, C4, 1.9 TDI (1994-) Common Issues
1. Rough Idling
Occurrence: 20%Cost to repair: $300Symptoms:
Rough idling, stumbling or hesitation when accelerating from a standstill.
2. Loss of Power
Occurrence: 18%Cost to repair: $800Symptoms:
Noticeable loss of power, especially at high engine speeds.
3. Coolant Leaks
Occurrence: 15%Cost to repair: $400Symptoms:
Visible signs of coolant leaking from the radiator, hoses or water pump.
4. DTC Codes P0201-P0400
Occurrence: 12%Cost to repair: $250Symptoms:
Faulty injector circuits, which can cause misfires and poor engine performance.
5. Rust Issues on Sills
Occurrence: 10%Cost to repair: $600Symptoms:
Corrosion on the sills, especially in areas with high humidity or exposure to road salt.
6. Faulty Air Mass Meter (AMM)
Occurrence: 9%Cost to repair: $200Symptoms:
Airflow meter failure can cause erratic engine behavior and poor fuel economy.
7. Timing Belt Failure
Occurrence: 8%Cost to repair: $1000Symptoms:
The timing belt may snap, causing significant engine damage.
8. Faulty Oxygen Sensor
Occurrence: 7%Cost to repair: $180Symptoms:
Oxygen sensor failure can lead to poor engine performance and increased emissions.
9. Clogged Diesel Particulate Filter (DPF)
Occurrence: 6%Cost to repair: $900Symptoms:
A clogged DPF can cause decreased engine power and increased exhaust backpressure.
10. Faulty Fuel Pressure Regulator
Occurrence: 5%Cost to repair: $420Symptoms:
Fuel pressure regulator failure can lead to poor fuel economy and erratic engine behavior.
11. Rear Main Bearing Failure
Occurrence: 4%Cost to repair: $1200Symptoms:
The main bearing may seize, causing significant rear-end damage.
12. Faulty EGR Valve
Occurrence: 3%Cost to repair: $220Symptoms:
EGR valve failure can lead to poor engine performance and increased emissions.
13. Crankshaft Position Sensor Failure
Occurrence: 2%Cost to repair: $190Symptoms:
The sensor failure can cause erratic engine behavior and poor fuel economy.