Buying guides · Audi A4 · UK
Audi A4 reliability
An honest look at how reliable the used Audi A4 really is, the two engine faults that catch buyers out, the best years to aim for, and exactly what to check before you hand over any money.
The short answer
The Audi A4 is classy, comfortable and good to drive, and a well-chosen one is a dependable used buy. There are two faults worth knowing about, both on the 2.0 TFSI petrol: heavy oil consumption on the earliest engines, and a timing chain tensioner that can rattle and, at worst, jump. Pick the right year and the A4 is on solid ground.
The specific car matters more than the badge. The sweet spots are the late B8 facelift (2013 onward) and the post-2018 B9, both of which had the worst of the early engine issues designed out. A serviced diesel TDI or a later petrol with a clean history is a far safer buy than a cheap early oil-burner with gaps in the paperwork.
Looking at a specific A4?
Paste the listing or the reg into CarMate. You get the full MOT history, mileage check, a read on the price against the market, and a clear view of whether it is worth viewing, worth negotiating, or worth walking away from.
Audi A4 common problems
These are the issues most worth knowing about on a used A4. Most are normal wear or known niggles, and all of them are checkable on the car in front of you.
Timing chain tensioner (2.0 TFSI)
The 2.0 TFSI petrol, mainly the early B8 (roughly 2009 to 2013) and the early B9 (2016 to 2017), can suffer a weak timing chain tensioner. It shows up as a metallic rattle for one to three seconds on cold start. Left too long the chain can jump timing and wreck the engine. Audi updated the design from mid-2018, so later 40 TFSI cars are rarely affected. Treat a cold-start rattle as a serious warning.
2.0 TFSI oil consumption
The earliest 2.0 TFSI engines (the CAEB code, around 2009 to 2011) are known for heavy oil consumption, sometimes a litre between services, caused by the PCV system and piston rings. Check the oil level on the dipstick, ask the seller how often they top it up, and be wary of any early petrol that has been run low on oil.
Water pump and thermostat (B9)
The B9 2.0 TFSI uses a combined plastic water pump and thermostat housing. Over time the internal seal swells and the plastic can crack, causing a coolant leak. It is the most commonly reported B9 petrol fault. Check for coolant loss, staining around the pump and a steady temperature gauge.
Carbon build-up (direct-injection petrols)
Like most direct-injection petrols, the 2.0 TFSI can build carbon on the intake valves over about 50,000 miles, which dulls performance and can cause misfires. It is a known maintenance item rather than a disaster, sometimes needing a walnut-blast clean. Factor it in on higher-mileage petrols.
Multitronic CVT automatic
Front-wheel-drive A4s with the Multitronic CVT automatic have a weaker reputation than the manual or the S tronic used on quattro cars, with the potential for expensive failure. If you want an automatic, a quattro with S tronic or a torque-converter box is the safer bet. Test any auto for smooth, judder-free drive.
Suspension and electrical niggles
Worn suspension arms and bushes cause knocks on higher-mileage cars, and minor electrical faults such as parking sensors, electric windows or infotainment glitches can appear. Check the ride for knocks and test every electrical feature before you buy.
Which A4 should you buy?
2.0 TDI (diesel)
The 2.0 TDI is the pick of the range for most buyers: strong on the motorway, economical and, from the 2013 facelift onward, well sorted. It suits higher mileage far better than the petrols. Buy one that has done real miles with a clean DPF history and the cambelt done on time.
2.0 TFSI (petrol)
The 2.0 TFSI is punchy and smooth, but which one you get matters enormously. The early B8 (2009 to 2011) can burn oil, and early cars can rattle the timing chain tensioner. The post-2018 B9 40 TFSI is the version to aim for, with those issues designed out. Check oil use and listen for a cold-start rattle.
1.4 / 1.8 TFSI and 35 TFSI
The smaller turbo petrols are cheaper to tax and insure and fine for lower-mileage town and commuting use, though they feel less muscular than the 2.0. They avoid the worst of the early oil-consumption saga but still deserve the usual history and service checks.
3.0 TDI, S4 and RS4
The 3.0 TDI is a superb mile-muncher, while the S4 and RS4 are seriously quick but attract hard driving and modifications. On any of these, check very carefully for abuse, a supporting history and evidence the big-ticket items have been maintained.Run the reg through CarMate to confirm the MOT and mileage record.
Frequently Asked Questions
Is the Audi A4 a reliable used car?
A well-chosen A4 is a dependable and classy used buy. The two faults to know about are both on the 2.0 TFSI petrol: oil consumption on the earliest engines and a timing chain tensioner that can rattle. Aim for the late B8 facelift (2013 on) or the post-2018 B9, or a serviced 2.0 TDI diesel, and check the specific car and you are on safe ground.
Which Audi A4 engine is the most reliable?
For most buyers the 2.0 TDI diesel from 2013 onward is the best all-rounder, strong for motorway miles and well sorted by then. If you prefer petrol, the post-2018 B9 40 TFSI is the one to aim for, as Audi had designed out the early oil-consumption and timing chain tensioner issues by then.
What are the best and worst years for the Audi A4?
The riskiest years are the early B8 petrols from around 2009 to 2012, due to 2.0 TFSI oil consumption and timing chain tensioner problems. The sweet spots are the late B8 facelift (2013 to 2015) and the post-2018 B9, both of which had the worst issues resolved. Diesel TDI models from 2013 on are among the safer choices.
Does the Audi A4 2.0 TFSI have oil consumption problems?
The earliest 2.0 TFSI engines (the CAEB code, roughly 2009 to 2011) are known for heavy oil use, sometimes a litre between services, from the PCV system and piston rings. Later engines are much improved. On any early petrol, check the oil level and ask about top-up history before you buy.
How many miles will an Audi A4 last?
A serviced A4, especially the 2.0 TDI, will commonly cover 150,000 miles and beyond. High mileage is not a dealbreaker on its own: a higher-mileage diesel with full history and a fresh cambelt is usually a safer buy than a cheap low-mileage early petrol with a patchy record.
What should I check on the MOT history of a used A4?
Look for a believable mileage climb (a sudden drop can point to clocking), recurring advisories for suspension, brakes or corrosion, and whether it fails on the same items each year. CarMate reads the full MOT history for any reg and flags mileage gaps and repeat problems automatically.
More used car buying guides
Looking at a different model? These honest reliability guides cover the common problems, the best engines and what to check before you buy.
Found a A4 you like?
Before you view it, run the listing or the reg through CarMate. You will know the MOT history, whether the mileage stacks up, how the price compares, and whether it is worth your time, all in one report. Buying privately, a car history check also confirms it is not on outstanding finance, written off or clocked before you commit.