Audi, A6, C4, 2.8 Quattro (1994-) Common Issues
1. Faulty Mass Airflow Sensor
Occurrence: 20%Cost to repair: $300Symptoms:
Poor engine performance, decreased power and rough idling
2. Timing Chain Tensioner Failure
Occurrence: 15%Cost to repair: $1200Symptoms:
Whining noise from the timing chain area, loss of power and oil leaks
3. Faulty Oxygen Sensor (Bank 1)
Occurrence: 12%Cost to repair: $200Symptoms:
Rough engine running, poor fuel efficiency and check engine light on
4. Faulty Electronic Throttle Control Module
Occurrence: 10%Cost to repair: $800Symptoms:
Unstable idle, hesitation when accelerating and surging
5. Faulty ABS Sensor (Front/Rear)
Occurrence: 9%Cost to repair: $250Symptoms:
ABS light on, decreased braking performance and spongy pedal feel
6. Water Pump Failure
Occurrence: 8%Cost to repair: $600Symptoms:
Increased engine temperature, overheating and leaks from the water pump area
7. Faulty Rear Main Seal
Occurrence: 7%Cost to repair: $400Symptoms:
Oil leaks from the rear main seal area, increased oil consumption and staining on the garage floor
8. Faulty Catalytic Converter
Occurrence: 6%Cost to repair: $900Symptoms:
Rough engine running, decreased power and poor fuel efficiency due to clogged catalytic converter
9. Faulty Electronic Stability Control (ESC) System
Occurrence: 5%Cost to repair: $500Symptoms:
Check engine light on, ESC warning light on and decreased vehicle stability during cornering
10. Faulty Air Suspension Sensors
Occurrence: 4%Cost to repair: $350Symptoms:
Air suspension lights on, uneven ride height and poor handling characteristics