Explore common problems, estimated repair costs and practical checks for the 2016–2021 Audi A4 2.0 Diesel Automatic B9. Use this guide to help assess a used car, then unlock a personalised report for the exact vehicle you're considering.
AdBlue warning, engine light, emissions fault message, or a mileage countdown saying the car may not restart.
Start the car from cold, let it idle, then drive until fully warm and cycle the ignition once during the viewing if the seller allows it.
£1,200
DPF or engine warning lights, reduced power, cooling fans running after shutdown, rising fuel use, or the car feeling strangled on acceleration.
Drive until warm, then accelerate steadily through the mid-range and let the car idle briefly after the drive.
£500
Coolant level dropping between services, dried pink residue in the engine bay, sweet smell after a drive, or weak cabin heat if the fault worsens.
Warm the car fully, park it, leave it idling briefly, then switch off and stand by the front of the car for a minute.
£950
It can be, but only if the individual car backs it up. For the 2016–2021 Audi A4 2.0 Diesel Automatic B9, treat model-level patterns as viewing priorities and let condition, history and inspection evidence decide.
The problem cards above list the model-level checks for this guide. Read them as priorities for inspection and paperwork review, not proof that every example will have those faults.
Look for evidence, not just assurances: MOT advisories, service history, repair invoices, warning lights, fluid leaks, tyre and brake condition, and how the car behaves on a proper test drive. And of course, look at your personalised Should I Buy This Car? report, outlining a full list of common issues in detail, a personalised road test, a plain-English explanation and a MotorIQ score.
The guide above gives you the model-level pattern. A personalised MotorIQ report checks the registration-specific record and turns it into an ownership view before you commit.
Or enter the vehicle manually