IsItAGoodCar
Reliability Guide

Common Problems with the
2023 Audi Q8 (4M8)

Audi unveiled the facelifted Q8 on 5 September 2023 for the 2024 model year and put it on UK sale on 10 October 2023 from £75,000: an octagonal singleframe grille flowing into revised Matrix LED headlights, new rear light bar with second-generation OLEDs, fresh paints and wheels, and the 55 TFSI e plug-in hybrid quietly wound down, with the car then sold on into 2026.

What changed for 2023

  • •Restyled front bumper, grille and laser-light option carried over from the facelifted A8
  • •Rear OLED light panels gained car-to-X warning symbols (triangle/arrow)
  • •Diesel and petrol mild-hybrid line-up revised; SQ8 and RS Q8 continued
  • •Interior received new inlays, upholstery and software update

Common MOT watch-outs

  • !Heavy 3.0 TFSI/TDI cars with 22-inch wheels write tyre and alignment advisories
  • !AdBlue quality warning sensor faults on late TDI cars - a frequent £500-£900 job and MOT emissions failure
  • !Air suspension height-sensor and compressor ageing on 2019-22 cars even after the 2023 facelift launch
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Known Issues
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Serious
1
Moderate
0
Minor

All Known Issues

48V Mild Hybrid System Faults

SeriousElectrics & Electronics

The belt-starter-generator can fail, disabling start-stop and energy recuperation, and potentially stranding the car when both batteries drain.

Est. Repair Cost: £0 (recall) – £1,500
Warning Signs:

Electrical system malfunction warning, Start-stop inactive, Rough engine restarts

What to Inspect:
  • Check for completed recall or service campaign work
  • Scan for 48V system fault codes
  • Verify battery health
Verified by IsItAGoodCar Research Team

Adaptive Air Suspension Leaks

SeriousSuspension & Chassis

The air springs can develop leaks causing uneven ride height, and the compressor burns out trying to compensate.

Est. Repair Cost: £800–£2,500
Warning Signs:

One corner sitting low after parking, Compressor running constantly, Air suspension warning light, Bouncy ride

What to Inspect:
  • Inspect ride height after standing overnight
  • Cycle suspension through height settings
  • Listen for compressor strain or hissing from wheels
Verified by IsItAGoodCar Research Team

TDI SCR / AdBlue System Faults

SeriousExhaust & Emissions

Diesel versions with SCR can develop dosing, heater or NOx sensor faults. A system fault may lead to a no-restart countdown even with sufficient AdBlue; diagnosis should distinguish fluid level from component failure.

Warning Signs:

AdBlue system warning, No-restart countdown

What to Inspect:
  • Check warning history and emissions repair invoices
  • Request a diagnostic check of dosing pressure, heater operation and NOx readings
Verified by IsItAGoodCar Research TeamUpdated

Infotainment and MMI Freezing

ModerateElectrics & Electronics

The dual-touchscreen MMI system can freeze, go black, or reboot spontaneously, affecting climate and vehicle controls.

Est. Repair Cost: £0–£900
Warning Signs:

Frozen or black screens, Climate controls unresponsive, Navigation or media dropouts

What to Inspect:
  • Test both touchscreens extensively
  • Check software version and update history
  • Verify no persistent error messages
Verified by IsItAGoodCar Research Team

Buying Tips for 2023 Audi Q8 (4M8)

  • The 2023-update car is a facelift, not a new model: shared generation means the same maintenance bills
  • Ask for OLED rear-panel function to be demonstrated - cracked panels are a costly owner item
  • Late-run stock (2025/26) was heavily discounted; compare against equivalent-age Q7 value before paying
20222024
Check a 2023 Audi Q8 (4M8) by Registration