IsItAGoodCar
Reliability Guide

Common Problems with the
2021 Audi A5 Mk2 (F5)

By 2021 the A5 F5 had matured with improved software and refined engines. This is generally the safest used F5 buy, though water pump leaks and diesel AdBlue issues still warrant attention.

What changed for 2021

  • •Updated engine range with improved efficiency
  • •Revised MMI software with improved stability
  • •Enhanced driver-assistance features
  • •Updated trim levels

Common MOT watch-outs

  • !Water pump leaks remain possible
  • !DPF issues on town-driven diesels
  • !Electrical glitches on higher-mileage cars
4
Known Issues
1
Serious
2
Moderate
1
Minor

All Known Issues

DL382 S tronic Gear Selection / Mechatronic Faults

SeriousGearbox & Transmission

Control or clutch faults can interrupt gear selection. Identify the gearbox code first: this entry applies to the longitudinal DL382 family, not every automatic sold under the same model name.

Warning Signs:

Gearbox warning, Delayed engagement or missing gears

What to Inspect:
  • Test drive from cold and again when warm
  • Check gearbox-specific service invoices and obtain a diagnostic report
Verified by IsItAGoodCar Research TeamUpdated

Water Pump / Thermostat Housing Leak

ModerateCooling System

Like the B9 A4, the A5 uses plastic cooling components that can seep or fail, causing repeated low-coolant warnings without an obvious puddle.

Est. Repair Cost: £350–£750
Warning Signs:

Low coolant warning, Pink residue at the front of the engine, Sweet smell after shutdown

What to Inspect:
  • Inspect coolant level from cold and look around the pump and housing for staining
  • Check whether the car needs repeated top-ups
  • Look for specialist or dealer invoices rather than generic coolant additions
Verified by IsItAGoodCar Research Team

NOx Sensor / AdBlue Faults

ModerateExhaust & Emissions

Diesel SCR hardware can trigger AdBlue countdowns, engine-management lights, and expensive sensor or injector replacement once the car is out of warranty.

Est. Repair Cost: £250–£1,200
Warning Signs:

AdBlue warning or no-start countdown, Engine light with emissions faults, Repeated warnings soon after topping up AdBlue

What to Inspect:
  • Scan the car for stored NOx and SCR faults
  • Ask for evidence of recent sensor, injector, or software work
  • Avoid diesel cars used only for short commutes if the emissions history is patchy
Verified by IsItAGoodCar Research Team

MMI / Virtual Cockpit Glitches

MinorElectrics & Electronics

Screen freezes, camera dropouts, and Bluetooth instability are common enough on early cars to be worth a deliberate test during inspection.

Est. Repair Cost: £0–£800
Warning Signs:

Rebooting or blank centre screen, Camera unavailable message, Phone pairing or audio dropping out

What to Inspect:
  • Use navigation, media, phone, and camera functions together
  • Check software update history
  • Verify that the car remembers paired devices and does not reboot during the drive
Verified by IsItAGoodCar Research Team

Buying Tips for 2021 Audi A5 Mk2 (F5)

  • Ensure all software updates have been applied
  • Check coolant level and inspect around the water pump
  • Generally a reliable choice if maintained correctly
2018–20202022–2024
Check a 2021 Audi A5 Mk2 (F5) by Registration