Compare Audi A4 AdBlue repair quotes from specialist garages

Since it was founded in 1909, Audi has been at the forefront of automotive innovation. It was the first to conduct crash tests, one of the first to use a dual-clutch gearbox, and in 1921, became the first German manufacturer to make a production car, the Audi Type K, with left-hand drive.

Impressively, Audi is also the most successful carmaker in the history of the World Car Awards, winning 11 titles since 2005 and five World Performance Car Awards as of 2022. Find out whether Audis are expensive to repair in this guide or take a look at how their maintenance costs compare with SEAT and Skoda.

AdBlue is a diesel exhaust fluid sprayed in small amounts onto exhaust gas, turning the NOx into less harmful nitrogen and water. If your car runs out of AdBlue while driving, its performance will be significantly reduced; when you stop the engine, it won't start again until you refill the tank.

Pump failure is one of the most common issues associated with the AdBlue system. Fortunately, an AdBlue pump repair or replacement isn't usually costly. Other problems include contamination and failure of the nozzle, NOx sensor and the AdBlue control unit.

You'll need to book an AdBlue system repair if your car develops any of these faults. Most of the time, the mechanic will run an AdBlue fault diagnostic first. Booking a car AdBlue service, which involves a top-up of fluid and a general check of the system's components, can help prevent the above issues.