Audi · 2008–2015
Common Audi A4 problems, and how to check them
These are the 3 faults owners and garages report most often on the Audi A4, from the most common down. For each one: what goes wrong, how to check it yourself, and the usual fix, so you know what you’re dealing with before you buy parts.
Fact-checked by a licensed car technician · last reviewed 28 September 2026
Problem 1
Audi A4: Blocked DPF or sticking EGR valve on the TDI
What goes wrong
Short trips stop the particulate filter from regenerating and soot clogs the EGR valve and cooler. A faulty DPF pressure sensor can block regeneration entirely.
How to check it yourself
Read codes and live data: DPF soot load and differential pressure (a reading that doesn’t change with revs points to the sensor or its hoses) and EGR position.
The usual fix
Rule out the pressure sensor and hoses, then regenerate (motorway drive or forced regeneration). Clean or replace a stuck EGR valve; a filter that stays blocked needs professional cleaning or replacement.
Signs: Loss of power, Check engine light, Rough idle
Fault codes: P2002, P2463, P2452, P2453, P0401, P0402
Problem 2
Audi A4: Burning oil on the 1.8 and 2.0 TFSI
What goes wrong
Piston rings with too-small oil drain holes clog with carbon, so oil gets past them and burns. Some engines use a litre every 1,000-2,000 km.
How to check it yourself
Fill to the max mark, note the mileage, and measure how much oil is gone after 1,000 km. Check for oily spark plugs and blue smoke on start-up; a compression and leak-down test shows ring wear.
The usual fix
The lasting fix is new, revised pistons and rings (a big engine job). Check the crankcase breather (PCV) first, as a failed one also raises oil use.
Signs: High oil consumption, Blue smoke, Misfire under load
Fault codes: P0300, P0301, P0302, P0303, P0304
Problem 3
Audi A4: Multitronic automatic judders or loses drive
What goes wrong
The Multitronic continuously variable gearbox wears its clutch pack and chain, and its control unit can fail. Signs are judder when pulling away, jerks when slowing down, and flashing gear letters.
How to check it yourself
Read the gearbox control unit with a VAG-capable tool and ask when the gearbox oil was last changed (it should be about every 60,000 km).
The usual fix
A fluid change and adaptation reset can help mild judder; worn clutches, chain, or a failed control unit mean a gearbox repair or exchange unit.
Signs: Harsh shifting, Transmission slipping, Hesitation
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer