Fault File
All models / All cars / Saloons & estates / Mercedes S-Class

Mercedes S-Class

All generations and engines together · 18,806 MOT tests in the 2025 data · typical mileage at age 7: 80k

First-time failure at age 7
10.8%
Across 2,125 tests. The average across all tracked models is 19.5%.
Rank at age 7
15 of 239
1 = lowest failure rate among the models tracked.
Typical mileage at age 7
80k miles
Check the mileage view below; low-mileage models can look better by age than they are.

Generation

Split by first-registration year. Cars registered in a changeover year can belong to either generation.

How this model wears

Mercedes S-ClassClass average, all tracked models

Known issues

Measured

Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.

What testers flag

Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.

Faults with the car itself

The rows that judge the model rather than its keeper. 9,271 tests in this band.

A suspension pin, bush or joint excessively worn
Advisory
7.5%class 6.7%
A suspension pin, bush or joint excessively worn
Fail
3.4%class 0.7%
Engine MIL illuminated indicating a malfunction
Fail
1.4%class 0.9%
Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users
Advisory
1.1%class 2.0%
Play in steering rack inner joint(s)
Advisory
1.0%class 1.1%
A wheel badly distorted or wear between wheel and hub at spigot mounting
Advisory
0.8%class 0.6%
Any fracture or welding defect on a wheel
Fail
0.8%class 0.1%
A transmission shaft flexible coupling excessively deteriorated
Advisory
0.7%class 0.1%

Wear, upkeep and luck

Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.

Tyre tread depth not in accordance with the requirements
Advisory
24.7%class 22.9%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
6.7%class 10.1%
A brake lining or pad worn below 1.5mm
Advisory
6.0%class 8.7%
A tyre seriously damaged
Advisory
5.9%class 13.4%
Brake disc or drum significantly and obviously worn
Advisory
4.7%class 3.4%
Tyre tread depth not in accordance with the requirements
Fail
2.5%class 2.2%
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
Minor
2.1%class 2.0%
Windscreen washers not working or not providing sufficient fluid to clear the windscreen
Fail
1.5%class 1.2%

Unconfirmed issues

Reported

Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.

Cold-start rattle from balance shaft wear (V6/V8 petrol)

Emerging

On the earlier W221 cars (2006 on) fitted with the M272/M273 V6 or V8 petrol engines, a rattle on cold start points to wear in the balance shaft and timing chain sprockets. It's a recognised weak spot in this engine family and it doesn't fix itself, it just gets louder with age. Repairs run from around £2,000 for a balance shaft job up to £4,000 if the timing chain and sprockets need doing too, and since the noise usually quietens down once the engine's warm, it's easy to miss on a test drive and won't show up on an MOT.

Reported on early W221 V6/V8 petrols · sources: Honest John

Suspension pump and strut failures (ABC / Airmatic)

Partly in the MOT data

The S-Class rides on complex self-levelling suspension: hydraulic Active Body Control on the W220 and W221, air-sprung Airmatic from the W222 on. Owners report suspension pump failures triggering dashboard warnings, and on older cars ABC strut parts becoming hard to source, to the point some owners retrofit conventional springs rather than fix the original system. This tracks with the measured MOT data for the saloon-estate segment, where suspension is the standout fault category, though the data can't tell you which specific part is behind it. A proper ABC or Airmatic repair runs well into four figures if it's more than a leak.

Reported from around 70k miles, worse on cars over 10 years old · sources: Honest John

7G-Tronic automatic gearbox: hesitant shifts or no reverse

Emerging

Higher-mileage W221 cars have a history of erratic gear changes and, in some cases, failing to select reverse at all, traced to a worn valve body or failing mechatronic unit rather than the gearbox itself. It tends to surface from around 100k-120k miles; a valve body or mechatronic replacement is typically £1,500-£2,500, more if the torque converter is also worn. None of this fails an MOT on its own, so it's easy to overlook unless you specifically try reverse and a full-throttle kickdown on the test drive.

Reported from 100k-120k miles · sources: Honest John

S500e hybrid drivetrain clunk on power handover

Hybrid only

On the S500e plug-in hybrid, some owners have reported a clunk and vibration from the rear of the car as the drivetrain hands over between electric and petrol power. It's logged as an isolated complaint rather than a widespread pattern, but worth checking specifically on a hybrid since the fix involves the transmission rather than a software update. Doesn't apply to the standard petrol or diesel S-Class range.

Isolated reports, hybrid models only · sources: Honest John

Electronics niggles: COMAND, Pre-Safe and screen glitches

Disputed

Across the generations there's a scattering of electrical gremlins rather than one clear fault: COMAND infotainment squeaks and odd drive-mode display behaviour on the W221, occasional DAB signal dropout on W222 diesels, and a screen described as "a bit glitchy" on the newest W223. None of it is consistent enough to pin down as a single design fault, and owners are split on whether it's a real weakness or just normal wear in a very complex car, but it's exactly the sort of thing that annoys an owner without ever appearing on an MOT sheet.

Reported across all three generations, no single clear pattern · sources: Honest John

Viewing one? Ask this

Built from the two sections above.

Start it stone cold and listen for a rattle from the front of the engine for the first few seconds. A rattle that fades as it warms up points to balance shaft/timing chain wear, worse on early W221 V6/V8 petrols.
Park it on level ground, walk away for a few minutes, then come back and look at the ride height. A sagging body or a lit suspension warning suggests a leaking ABC strut or a tired Airmatic compressor.
Look underneath at each corner for fluid staining or a visibly wet strut. Weeping fluid means a leak, common on both ABC and Airmatic as they age.
On the test drive, floor it for a kickdown and separately do a slow, full-lock reverse manoeuvre. Hesitation, flaring, or a refusal to select reverse points to a worn valve body or mechatronic unit.
If it's an S500e or other hybrid, drive it so it switches between electric and petrol power. A clunk or shudder on the handover is the known hybrid drivetrain complaint.
Check the MOT history for repeated suspension advisories on the same corner. Recurring suspension advisories match the measured fault pattern for this model and point to worn ABC/Airmatic parts rather than simple bushes.
Cycle through every infotainment screen and function, watching for freezing or flicker. Glitchy COMAND/MBUX behaviour is a known niggle across generations and can be costly to sort once out of warranty.

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