MERCEDES S CLASS Common Problems & Reliability

Based on 2,934 MOT tests from 220 vehicles analysed by VehicleScore. The figures below describe that VehicleScore sample. Recurring issues seen in VehicleScore MOT data are not a claim that every MERCEDES S CLASS has the same fault.

MERCEDES S CLASS's have a very good reliability rating of 643/999. The score was calculated from the average of every MERCEDES S CLASS that has had a registered MOT.

We calculated all of the below figures by getting the score from each vehicle make/model/year/fuel, which are each calculated a score. We then generate the average score, taking into account factors such as mileage and emissions.

MERCEDES S CLASS (example)

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Fuel Type	Year	Reliability Score	Avg Mileage	Sample Size
Diesel	2019	807/999Excellent	92,626 miles	972 vehicles
Diesel	2018	784/999Very good	92,489 miles	1,146 vehicles
Diesel	2017	764/999Very good	89,838 miles	1,393 vehicles
Diesel	2014	741/999Very good	91,666 miles	1,323 vehicles
Diesel	2011	597/999Above average	93,863 miles	788 vehicles
Diesel	2010	537/999Above average	84,782 miles	789 vehicles
Diesel	2007	529/999Above average	90,308 miles	992 vehicles
Diesel	2003	501/999Above average	96,258 miles	925 vehicles
Petrol	2003	555/999Above average	88,293 miles	965 vehicles
Diesel	2001	525/999Above average	96,087 miles	1,029 vehicles
Petrol	2001	556/999Above average	88,715 miles	1,253 vehicles
Petrol	1999	586/999Above average	102,095 miles	776 vehicles
Petrol	1996	618/999Good	106,878 miles	579 vehicles
Petrol	1995	653/999Good	110,043 miles	626 vehicles
Petrol	1987	711/999Very good	136,216 miles	513 vehicles
Petrol	1986	731/999Very good	132,551 miles	590 vehicles
Petrol	1983	732/999Very good	127,622 miles	599 vehicles

How reliable is the MERCEDES S CLASS?

Based on 2,934 MOT tests from 220 vehicles analysed by VehicleScore.

Vehicles

220

MOT tests

2,934

Pass rate

84.2%

Median mileage

90,422 mi

Recurring issues seen in VehicleScore MOT data are inspection findings from this sample. They are not a statement that every MERCEDES S CLASS has the same fault. The median VehicleScore in this sample is 673 out of 999.

Common MERCEDES S CLASS MOT problems

These groups combine equivalent MOT comments, such as the same tyre note on different corners. Counts are comment occurrences in the sample, not a percentage of cars.

Tyre wear

VehicleScore MOT data includes 432 advisory comments and 66 failure comments in this group. Seen as both an advisory and a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record tyres that were worn, damaged, or close to the legal tread depth when the car was inspected.

What to inspect

Check the tread depth and look for uneven wear, cracking, or damage on all four tyres.

Example MOT wording: OFFSIDE REAR TYRE WORN CLOSE TO LEGAL LIMIT/WORN ON EDGE (5.2.3 (E))

Corrosion

VehicleScore MOT data includes 128 advisory comments in this group. Seen mainly as an advisory. These are comment occurrences, not a share of all cars.

These MOT comments record corrosion the tester could see on the body or structure. Corrosion already named on a spring, brake, or other component is counted with that component.

What to inspect

Inspect the underside, sills, and subframe for heavy corrosion, especially where an advisory mentions it.

Example MOT wording: OFFSIDE FRONT BRAKE PIPE CORRODED, COVERED IN GREASE OR OTHER MATERIAL (1.1.11 (C))

Brake pad wear

VehicleScore MOT data includes 87 advisory comments in this group. Seen mainly as an advisory. These are comment occurrences, not a share of all cars.

These MOT comments record brake pads that were worn or below the inspection limit.

What to inspect

Ask for recent pad replacement and look at the remaining pad thickness.

Example MOT wording: FRONT BRAKE PAD(S) WEARING THIN (1.1.13 (A) (II))

Brake disc wear

VehicleScore MOT data includes 51 advisory comments in this group. Seen mainly as an advisory. These are comment occurrences, not a share of all cars.

These MOT comments record brake discs that were worn, scored, pitted, or corroded.

What to inspect

Look at the disc faces for deep scoring, a lip at the edge, and corrosion.

Example MOT wording: FRONT BRAKE DISC WORN, PITTED OR SCORED, BUT NOT SERIOUSLY WEAKENED (1.1.14 (A) (II))

Oil leak

VehicleScore MOT data includes 48 advisory comments in this group. Seen mainly as an advisory. These are comment occurrences, not a share of all cars.

These MOT comments record an oil leak noted by the tester. Shock absorber misting is counted as a damper issue, not as an engine oil leak.

What to inspect

Look under the engine for fresh oil, and check the oil level.

Example MOT wording: OIL LEAK, BUT NOT EXCESSIVE (8.4.1 (A) (I))

Parking brake faults

VehicleScore MOT data includes 46 failure comments in this group. Seen mainly as a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record a parking brake that did not hold well enough or had a component defect.

What to inspect

Test that the parking brake holds the car on a slope and releases cleanly.

Example MOT wording: PARKING BRAKE: EFFICIENCY BELOW REQUIREMENTS (3.7.B.7)

Ball joint wear

VehicleScore MOT data includes 32 failure comments in this group. Seen mainly as a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record a worn or damaged ball joint. Track rod ends are counted with steering, not here.

What to inspect

Ask for the joint to be checked for play with the suspension loaded and unloaded.

Example MOT wording: OFFSIDE FRONT LOWER SUSPENSION ARM BALL JOINT EXCESSIVELY WORN (5.3.4 (A) (I))

Engine warning lamp

VehicleScore MOT data includes 15 failure comments in this group. Seen mainly as a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record an engine warning lamp that was on, or did not work, during the inspection.

What to inspect

Switch on the ignition and confirm the lamp comes on and then goes out. Ask what was diagnosed if it stayed on.

Example MOT wording: ENGINE MIL INOPERATIVE OR INDICATES A MALFUNCTION (8.2.1.2 (H))

MERCEDES S CLASS MOT reliability by year

A model year is only commented on when VehicleScore has at least 5 vehicles from that year.

Year	Vehicles	MOT tests	Pass rate	Recurring issues seen
2019	17	114	90.4%	Tyre wear, Ball joint wear
2018	18	133	94%	Tyre wear, Brake pad wear
2017	19	180	92.8%	Tyre wear, Ball joint wear
2016	20	180	86.1%	Tyre wear, Brake pad wear
2015	17	163	89%	Tyre wear, Ball joint wear
2014	14	151	92.1%	Tyre wear, Brake disc wear
2013	6	87	82.8%	Tyre wear, Brake pad wear
2012	9	125	89.6%	Tyre wear, Corrosion
2011	9	128	89.1%	Tyre wear, Corrosion
2010	6	88	89.8%	Tyre wear, Brake disc wear
2009	9	172	73.3%	Tyre wear, Brake pad wear
2008	10	198	74.7%	Tyre wear, Brake pad wear
2007	15	305	81.3%	Tyre wear, Brake pad wear
2006	11	227	84.1%	Corrosion, Tyre wear
2001	5	103	84.5%	Tyre wear, Brake disc wear

What to check when buying a used MERCEDES S CLASS

This is an inspection checklist based on MOT comments in the VehicleScore sample. It does not mean the car you are looking at has these defects.

Tyre wear. Check the tread depth and look for uneven wear, cracking, or damage on all four tyres.
Corrosion. Inspect the underside, sills, and subframe for heavy corrosion, especially where an advisory mentions it.
Brake pad wear. Ask for recent pad replacement and look at the remaining pad thickness.
Brake disc wear. Look at the disc faces for deep scoring, a lip at the edge, and corrosion.
Oil leak. Look under the engine for fresh oil, and check the oil level.
Parking brake faults. Test that the parking brake holds the car on a slope and releases cleanly.
Ball joint wear. Ask for the joint to be checked for play with the suspension loaded and unloaded.
Engine warning lamp. Switch on the ignition and confirm the lamp comes on and then goes out. Ask what was diagnosed if it stayed on.

Buying a MERCEDES S CLASS?

Common problems tell you what can affect MERCEDES S CLASSs generally. VehicleScore can check the history of the actual car you're considering.

Where does this data come from?

VehicleScore analyses MOT histories from vehicles in its own dataset. Sample sizes vary by model, and a small sample is labelled as such. MOT data records roadworthiness and inspection defects. It does not capture every mechanical or electronic problem a car can have, and a comment on one test is not proof that the model has an inherent fault.

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