2021 Audi A4 Pre-Purchase Inspection Checklist
Known Issues — 2021 Audi A4
MODERATE
Quattro rear differential oil seal leaks on AWD models
MODERATE
ADAS camera calibration drift causing lane departure false warnings
MODERATE
Carbon buildup on intake valves requiring periodic cleaning
MINOR
MMI infotainment system slow boot and connectivity issues with Apple CarPlay
MODERATE
Oil consumption on some TFSI units
MINOR
Wireless charging pad heat buildup causing phone warnings
What to Inspect
- Check oil level and ask about consumption between oil changes
- Verify all ADAS systems — adaptive cruise, lane keeping, emergency braking
- Test wireless and wired Apple CarPlay/Android Auto
- Scan all modules for fault codes
- Check for quattro rear differential oil leaks
- Confirm service history is up to date with Audi dealer records
Expected Maintenance Costs
| Service | Interval | Cost |
|---|---|---|
| Oil change (synthetic) | every 10,000 miles | $130-$170 |
| DSG S tronic service | every 40,000 miles | $300-$450 |
| Spark plugs | every 40,000 miles | $150-$200 |
| Quattro rear differential fluid | every 40,000 miles | $150-$220 |
| Brake fluid flush | every 2 years | $100-$150 |
| Pollen/cabin filter + air filter | every 20,000 miles | $80-$120 |
| Brake pads and rotors (front) | every 40,000-60,000 miles | $400-$700 |
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