Audi
1,539 MOT tests analysed. sits above the UK fleet average — here's where A4 S LN Black ED 35tdi Mhev SAs pass, fail, and end up on the retest sheet.
That's 12.1 points above the UK fleet average across our 1,984 tracked models — a confident result.
Pass
89.6%
Pass-after-fix
0.6%
Fail
9.0%
Avg miles
36,588
Pass + Pass-after-fix + Fail = 100%
Diesel cars registered from September 2015 generally meet Euro 6 — compliant in London ULEZ, Birmingham CAZ, Bristol CAZ, and Glasgow LEZ.
Performance by cohort
2 year bands · 1,539 tests
Pass rate climbs 2.8 points across the cohorts — newer A4 S LN Black ED 35tdi Mhev SA examples clear the test more reliably than the early cars.
Pass
87.0%
Fail
13.0%
PRS
0.0%
Avg mileage at test
44,222 mi
Pass
89.8%
Fail
8.8%
PRS
0.6%
Avg mileage at test
36,055 mi
Cohort = vehicle's first-registration year band. Same model, different generations of build.
The picture
Across 1,539 MOT tests, the A4 S Ln Black Ed 35tdi Mhev Sa returns 89.6% first-time pass — comfortably ahead of the UK fleet average. The single most-logged Major fail is tyre tread under the limit. A tyre with the cords showing and windscreen damage round out the top three. Average tested mileage sits at 36,588, which is the lens to read those failure rankings through. If you own one and the next test is close, the ranked list below is a sensible pre-test checklist.
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Tyre tread depth not in accordance with the requirements
40 occurrences · 2.6% of tests
A tyre cords visible or damaged
35 occurrences · 2.3% of tests
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
29 occurrences · 1.9% of tests
A tyre seriously damaged
22 occurrences · 1.4% of tests
A tyre seriously damaged
17 occurrences · 1.1% of tests
Wiper blade defective
15 occurrences · 1.0% of tests
Number plate does not conform to the specified requirements
10 occurrences · 0.6% of tests
A tyre seriously damaged
9 occurrences · 0.6% of tests
Engine MIL illuminated indicating a malfunction
9 occurrences · 0.6% of tests
A spring or spring component fractured or seriously weakened
9 occurrences · 0.6% of tests
Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.
Worst-case fix budget · top 2 failures
£120–£190
If every one of this A4 S LN Black ED 35tdi Mhev SA's most-logged Major fails hit at the same MOT, that's the real-world UK garage range. Reality is usually one or two items, not all of them. Open the estimator →
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Picked against this car's top failure patterns. Affiliate links to Amazon UK — we earn a small cut at no cost to you. Disclosed up-front, doesn't shape the data.
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Owner reports · Honest John
Verbatim faults logged by owners on honestjohn.co.uk over recent years. We didn't summarise — these are the words people typed in.
What's good
Exceptional quality, packed with technology, impressive refinement and comfort, efficient and economical.
Adblue module control unit failure reported on 2016 Audi A4 Avant Ultra 2.0 TDI. Owner quoted £930 to replace the unit.
Owners of three month old car reports problems with the infotainment system. When they get in the car and drive off an error message often comes up saying "The selected user has not been used in this vehicle for a while. Please enter the MyAudi user data again. It will be necessary to switch to the guest user to do this." Local dealer has told the owners that Audi UK are aware of the fault and they are awaiting a software fix from Audi Germany.
Report of failure of EGR on 2015 Audi A4 B9 EA288 2.0TDI at 60,000 miles. Cost of replacement was £1,500.
Report of "persistent vibrations coming through the accelerator pedal and the steering wheel, often simultaneously" in November 2015 Audi A4 B9 avant 8-speed auto, 3.0 TDI V6 272HP. Has had replacement of several expensive parts under guarantee due to factory recalls (4 camshafts, crank shaft, chain tensioner), but problem's remains. In D the vibrations arrive around 1,250 rpm especially when accelerating. Owner notices that despite regular cleaning and quality fuel all the time, the engine is also quite noisy when accelerating: "it's as if there's a part somewhere which is noisier than it should be and injects vibrations into the mix when increasing speed." Also, when the car is hot and in traffic it can start to tremble slightly until shifted into Neutral. If driver leaves car in S in traffic, the vibrations are slightly stronger still.
Owner found that the 19-inch optional alloy wheels fitted to his March 2017 Audi A4 2.0TDI quattro s-tronic s-line had increased its CO2 from 114g/km to 121g/km and put up his annual VED from £30 to £120.
Complaint of "soft knocking sound around driver's right ear" when driving on a "roughish road surface" in a new Audi A4 B9. Seems to be from an area around drivers window/door lock/door pillar. Likely to be the inertia reel seatbelt pendulum.
Report of vibration from drivetrain of November 2018 Audi A4 B9 avant 272 3.0 V6 now at 45k miles: At 1,250 rpm, whether in D or S mode, there is vibration which passes through the accelerator pedal and steering wheel. Also at 1,750 rpm when cruising on the motorway at 80 mph with cruise control on in 8th gear it doesn't feel as smooth as it should. Finally, when around 2,000 rpm the car feels unrefined and actually noisy for an Audi V6 diesel.
Audi dealer told owner that intermittent shudder in 1st gear when releasing the clutch of his 2016 Audi A4 may be due to "driver error" that has damaged the dual mass flywheel and want £1400 to "investigate" (this must include the costs of a new DMF and clutch).
Report of two failed transmissions on 2015 Audi S4 in 25,000 miles. Unfortunately owner failed to renew extended warranty.
Various niggling problems reported with June 2016 Audi A4 B9. In May 2017 the car failed twice, on consecutive days, and the Engine Management Unit was replaced. At the same time owner advised the dealer that the electronic dipstick was reporting the engine oil level as being at full capacity although he had not topped up the oil, that the trip odometer and the long term memory were intermittently clearing to zero and the external thermometer was occasionally displaying obviously faulty temperatures. In July 2017 he again reported to the dealer the potential problems with the electronic dipstick and the other display issues. He was simply told that "new cars don't use oil". The engine oil has not been topped up since first delivery. The trip odometer and long term memory inexplicably reset to zero yesterday.
Report that on 4th August a 7 month old 2017 Audi A4 Avant came to a sudden halt from 38mph for no reason, on a clear road, causing the following car to crash into the back of it.
Source: honestjohn.co.uk · 11 reports indexed
Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.
If you own an A4 S LN Black ED 35tdi Mhev SA and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.
