Common problems

Mercedes-Benz R-Class common problems

What MOT testers find on the Mercedes-Benz R-Class: the parts that fail or get advisories most often at each age, against all cars of the same age. From 6,031 DVSA MOT tests taken 2022 to 2025.

MOT data updated 28 September 2026

At 16 years, the most tested age

Lights and electrics fails per 100 MOTs (n=1,304)14.6

All cars at 16 years (n=4,858,625)20.4

Brakes advisories and minor defects per 100 MOTs (n=1,304)35.9

All cars, same age (n=4,858,625)29.5

What stands out

Brakes fails show up on 12.9 of every 100 MOTs of a Mercedes-Benz R-Class at 16 years old (n=1,304), against 11.6 for all cars of that age (n=4,858,625).
Suspension fails are less common: 6.1 per 100 MOTs against 17.1 for all cars at the same age.
The fail item testers record most often at 16 years: side/position light not working, on 4.5 per 100 MOTs (all cars 5.9).
The most common advisory or minor defect: engine oil leaks: leak, but not excessive, on 27.5 per 100 MOTs.

Problems by part at 16 years

How many of every 100 MOTs found a fail, or an advisory or minor defect, in each area. A test with faults in two areas counts in both.

Mercedes-Benz R-Class at 16 years (n=1,304) against all cars at 16 years (n=4,858,625). Per 100 MOTs.
Area	Fails	All cars	Advisories	All cars
Lights and electrics	14.6	20.4	11.0	15.3
Brakes	12.9	11.6	35.9	29.5
Exhaust, emissions and leaks	6.4	6.2	29.6	12.0
Suspension	6.1	17.1	20.4	33.7
Tyres	6.1	7.5	22.9	28.4
Body and structure	5.6	7.6	14.0	12.6
Windscreen, wipers and mirrors	3.0	6.8	5.8	5.7
Seat belts and airbags	2.5	2.1	0.5	1.1
Steering	1.3	3.4	0.8	4.6
Road wheels	0.8	0.6	0.2	1.5
Number plates and VIN	0.6	0.6	3.6	4.8

What testers fail most on the R-Class at 16 years

Fail items on the Mercedes-Benz R-Class at 16 years (n=1,304), per 100 MOTs, with all cars at the same age (n=4,858,625).
Item	Area	Per 100 MOTs	All cars	Typical repair (estimate)
Side/position light not working	Lights and electrics	4.5	5.9	£10 to £47 per lamp
Driveshaft CV boot split	Body and structure	4.0	2.9	£88 to £196 per boot (rough guide)
Brake light not working	Lights and electrics	3.1	4.0	£10 to £47 per lamp
Rigid brake pipes: excessively corroded	Brakes	2.8	1.6	£137 to £392 per car (rough guide)
Shock absorber leaking	Suspension	2.5	1.6	£122 to £484 per axle (pair) (rough guide)
Tyre tread below 1.6 mm	Tyres	2.3	3.1	£88 to £145 per tyre
Handbrake too weak	Brakes	2.2	2.5
Rear fog lamp: not working	Lights and electrics	2.0	0.8	£10 to £47 per lamp
Tyre with cords exposed	Tyres	2.0	1.8	£88 to £145 per tyre
Service brake performance: excessively binding	Brakes	1.7	1.4	£55 to £267 per wheel (rough guide)

Early warnings: advisories and minor defects at 16 years

Advisories and minor defects are recorded, but the car still passes. Across all cars, a part with an advisory or minor defect failed at the next MOT 5.5 times in 100 (n=88,666,940 pairs of consecutive MOTs), against 0.3 times in 100 when the same part had none (n=12,936,860,350).

Advisories and minor defects on the Mercedes-Benz R-Class at 16 years (n=1,304), per 100 MOTs, with all cars at the same age (n=4,858,625).
Item	Area	Per 100 MOTs	All cars	If it needs replacing (estimate)
Engine oil leaks: leak, but not excessive	Exhaust, emissions and leaks	27.5	10.7
Rigid brake pipes: corroded, covered in grease or other material	Brakes	20.5	8.8	£137 to £392 per car (rough guide)
Tread depth: worn close to legal limit/worn on edge	Tyres	16.3	18.2	£88 to £145 per tyre
Drive shaft joints: constant velocity boot severely deteriorated	Body and structure	11.4	3.5
Shock absorbers: has light misting of oil	Suspension	8.9	4.1	£122 to £484 per axle (pair) (rough guide)
Brake discs: worn, pitted or scored, but not seriously weakened	Brakes	7.2	11.2	£148 to £376 per axle (rough guide)
Suspension arm pins and bushes: pin or bush worn but not resulting in excessive movement	Suspension	6.5	8.7	£92 to £237 per arm (rough guide)
Brake pads: wearing thin	Brakes	6.1	6.8	£72 to £174 per axle (rough guide)
Tyre condition: slightly damaged/cracking or perishing	Tyres	4.7	9.5	£88 to £145 per tyre
Windscreen: damaged but not adversely affecting driver's view	Windscreen, wipers and mirrors	3.8	3.4

Repair estimates are a guide for an independent garage: labour at the national median local garage rate (median £78 an hour from 65 garages, ONS price quotes) times estimated labour hours, plus a parts band. Labour hours and most parts bands are estimates, not quotes, and prices vary by model, engine and region. A warning light fault shows the cost of the diagnosis only.

How problems change with age

Fails per 100 MOTs in the three most common areas at 16 years. Ages with fewer than 1,000 tests are not shown.
Age	Tests (n)	Lights and electrics	Brakes	Exhaust, emissions and leaks
12 years	1,124	11.4	9.3	4.5
13 years	1,141	9.6	9.6	4.7
14 years	1,204	12.3	12.2	6.1
15 years	1,258	13.8	13.0	6.0
16 years	1,304	14.6	12.9	6.4

What to check on a viewing

On the Mercedes-Benz R-Class, testers most often record side/position light not working; driveshaft CV boot split; brake light not working. Look at these first, then the areas below.

Lights and electrics

With someone outside, try every light: dipped and main beam, indicators, brake lights, fog lights and number plate lamps.
Check that the warning lights come on with the ignition and go out once the engine runs.
Look for misted, cracked or yellowed headlamp lenses.

Brakes

On the test drive the car should stop in a straight line without pulling, juddering or grinding.
Look at the discs through the wheels for a deep lip, heavy rust or scoring.
Check that the handbrake or electronic parking brake holds the car on a slope.
Ask when the pads, discs and brake fluid were last changed, and for the receipts.

Exhaust, emissions and leaks

Start the engine from cold if you can and watch the exhaust for blue or black smoke.
Check that the engine warning light goes out after starting and stays out on the test drive.
Look under the car and around the engine for oil or fluid leaks, and listen for a blowing exhaust.

Ask for the car's MOT history and service record: advisories that repeat from one year to the next show what has been left. GOV.UK MOT history.

Questions

What are the most common problems on the Mercedes-Benz R-Class?

At 16 years, the age with the most MOT tests (1,304), the fail items testers record most often on the Mercedes-Benz R-Class are side/position light not working (4.5 per 100 MOTs), driveshaft CV boot split (4.0 per 100 MOTs), brake light not working (3.1 per 100 MOTs). The most common advisories or minor defects are engine oil leaks: leak, but not excessive (27.5) and rigid brake pipes: corroded, covered in grease or other material (20.5).

Which parts of the Mercedes-Benz R-Class fail more often than on other cars?

At 16 years: brakes (12.9 per 100 MOTs against 11.6 for all cars). Compared with 4,858,625 MOTs of all cars the same age.

Mercedes-Benz R-Class problems by area

Other Mercedes-Benz models

All Mercedes-Benz models · Common problems by make

Read this with care. A fail rate is not a measure of build quality. How far cars are driven, how they are used and how well owners maintain them all change it, and wear items such as tyres and brake pads are common fails. Compare a model only with cars of the same age. Methodology and limits.

The all cars figures cover all class 4 vehicles (cars and light vans) tested at the same age.

Looking at a Mercedes-Benz R-Class?

These figures describe the model, not the car in front of you. Found one you might buy? See what the VetTheCar Buying Report covers, or use the tools that work without a registration.

See a sample report Car tools · MOT fail rates by model · Compare models by MOT record

Repair estimates: ONS consumer price quotes for local garage labour (09/2025 to 08/2026), the MOT inspection manual for defect wording, and estimated labour hours and parts bands. Not affiliated with or endorsed by ONS.

Source

Contains public sector information licensed under the Open Government Licence v3.0. Source: DVSA anonymised MOT test data, class 4 normal MOT tests, 2022 to 2025. MOT data updated 28 September 2026.

Not affiliated with or endorsed by DVSA. How we calculate these figures · Data sources