Generations at a Glance
The A4 has gone through three modern generations that matter to most used-car buyers: the B7 (2006–2008), B8 (2008–2016), and B9 (2017–present). Each has a distinct engine family and a distinct reliability profile.
| Generation | Years | Engine (US) | Reliability Summary |
|---|---|---|---|
| B7 | 2006–2008 | 2.0T (BWT), 3.2 V6 | Solid, aging — timing chain by 100K |
| B8 | 2008–2016 | 2.0T TFSI (EA888 Gen 1/2) | Known oil consumption on Gen 1 (2009–2012) |
| B9 | 2017–present | 2.0T TFSI (EA888 Gen 3) | Significantly improved; fewer endemic issues |
B8 A4 (2008–2016): What You Need to Know
The B8 is the generation that comes up most often in shops and forums because the early 2.0T engine (EA888 Generation 1, used from 2008 through approximately 2012) has a well-documented oil consumption problem caused by piston ring wear. Cars with this engine can burn through a quart of oil per 1,000 miles while running perfectly otherwise — no smoke, no fault codes, no warning signs beyond low oil level.
The Oil Consumption Issue: What It Actually Is
The EA888 Gen 1 piston rings don't seat properly, allowing oil to pass into the combustion chamber and burn off. Audi extended the warranty on this issue and updated the fix multiple times. The definitive repair is a piston ring replacement using updated Audi pistons — a 20 to 25 hour job that runs $2,000 to $3,500 depending on the shop. The repair is worth doing on cars under 100K miles in otherwise good condition. Above 120K miles, the math gets complicated and deserves an honest conversation about the car's total value and expected remaining life.
Breather modifications are not a fix. Some shops offer a crankcase breather modification for a few hundred dollars. It can reduce visible oil consumption symptoms, but it doesn't stop the engine from wearing. We don't recommend it as a primary solution.
Timing Chain — Pre-2013 2.0T
B8 A4s with the pre-2013 2.0T engine have a timing chain tensioner made of plastic that deteriorates over time. The failure pattern is consistent: cold-start rattle that disappears after a minute or two as oil pressure builds. The rattle is the chain slapping the guide as the tensioner fails to maintain proper tension. Catch it early and a timing chain service (chain, tensioner, guides) runs 7 to 9 hours of labor. Ignore it and a jumped chain means bent valves and a much larger bill. We check every pre-2013 B8 for tensioner wear during inspection.
DSG and S Tronic
Most B8 A4s came with either a 6-speed manual or the 7-speed S tronic (DL501) paired with quattro. The DL501 is a larger, more robust dual-clutch than the DQ250 used in FWD Audis — but it still needs fluid service around 40,000 miles. The mechatronic unit in the DL501 is less failure-prone than the DQ250's, but it's not immune. Low-speed shudder or hesitation pulling away is the early sign.
Multi-Link Suspension Wear
The B8's multi-link rear suspension is excellent for handling and predictable in its wear pattern. Control arms, rear trailing arms, and toe links typically need attention between 80,000 and 110,000 miles. Symptoms start subtle — slight wandering at highway speed, a clunk over sharp bumps — and get more pronounced. Budget for a full rear suspension refresh around 100K miles if you plan to keep the car. Always follow suspension work with a four-wheel alignment.
B8.5 (2013–2016): The Updated Generation
From 2013 onward, Audi redesigned the EA888 engine (Gen 2) with updated piston rings and a revised tensioner. The oil consumption issue is largely absent in Gen 2 cars, and the timing chain design improved. B8.5 A4s are generally a better used buy than early B8s, assuming similar maintenance history. They still benefit from walnut blasting around 60K miles — all direct injection engines do.
B9 A4 (2017–Present): A Meaningfully Different Car
The B9 generation sits on a new platform (MLB evo), gained the EA888 Gen 3 engine, and dropped most of the reliability baggage of the B8. The Gen 3 2.0T has revised piston rings, improved oil control, and a redesigned tensioner. B9 A4 owners typically encounter far fewer engine-related issues in the first 80,000 miles than B8 owners did at the same point. The main things to keep up with: oil changes on schedule (5,000–7,500 miles with the right spec), walnut blasting by 60K miles, and brake fluid every two years.
B9 MMI and Electronics
The B9 introduced Audi's Virtual Cockpit and a significantly more complex infotainment architecture. Software issues are occasional but real — frozen screens, Bluetooth disconnects, navigation glitches. Most resolve with updates available through VCDS or at a shop with the appropriate diagnostic software. They're annoying but not mechanically significant.
S4 Notes
The B8 S4 uses the 3.0T supercharged V6 — the supercharger coupler issue from the A6/Q7 applies here too. B9 S4 switched to the EA839 3.0T turbocharged V6, which is a fundamentally different engine without the coupler concern. B9 S4 has been reliable in the first 60K miles; longer-term data is still accumulating.
What to Check Buying a Used A4
- Confirm the engine generation: 2009–2012 with 2.0T = EA888 Gen 1 (oil consumption risk). Request an oil consumption test before buying.
- Cold-start it. Listen for timing chain rattle that clears after 60–90 seconds.
- Check the DSG at low speed — pull away from a dead stop slowly and feel for shudder.
- Get the service history. An A4 with no DSG service record past 60K miles has an overdue transmission.
- Have the rear suspension inspected. Any play in control arms or toe links is a near-term repair cost.
- Request a pre-purchase inspection from a shop with VCDS. Generic OBD scanners miss module-level faults.