Audi A4 Mk2 (B6) Problems by Year

The second-generation Audi A4 (B6), produced from 2000 to 2004, is often remembered as the model that firmly established Audi's reputation for class-leading interior quality. Positioned as a direct rival to the BMW 3 Series (E46), it offered a more understated and refined approach to executive motoring, with a build quality that many enthusiasts believe remains unsurpassed by later generations. In the UK, it was a massive success, particularly in Avant (estate) form, and it remains a highly regarded budget used choice today for its robust mechanicals and timeless design. Reliability is generally excellent, but there are specific drivetrain caveats to consider. The Multitronic CVT gearbox found on front-wheel-drive automatics is the B6's most notorious weak point, prone to expensive electronic and mechanical failures; the manual or Tiptronic automatic (Quattro models) are far safer bets. Mechanically, the 1.9 TDI diesel is legendary for its 200,000-mile durability, though the PD (Pumpe Düse) units require specific high-quality oil to prevent camshaft wear. Petrol 1.8T owners should also be wary of oil sludge buildup in the pickup pipe if service history has been neglected. When buying a B6 in the UK, the priority should be inspecting for structural corrosion on the front wheel arches, where foam inserts can trap moisture and cause the metal to rot from the inside out. Plenum chamber flooding is another common issue, where blocked drains under the battery cause water to overflow into the cabin and fry the expensive Convenience Control Unit located under the carpet. For the best used experience, seek out a 1.9 TDI (130bhp) manual with a documented service history, and ensure the aluminum multi-link front suspension is free from clunks, as a full refresh can be a labor-intensive and costly task.

Select a year below to see the specific problems affecting that model year, with estimated repair costs and severity ratings.