Mercedes-Benz S-Class Problems (9 Known Issues)

The Mercedes Benz S-Class was introduced in 1972 and it was the designation for the top-of-the-line Mercedes-Benz models.

This S-class features a series of full-sized luxury sedans, limousines, and even armored models.

However, as good as this may sound, the S-class comes with some major flaws and some of them have we highlighted below. Jump on this article to find out what problems.

1. Braking Problems

Brake failure was an issue with the Mercedes Benz S-Class.

An owner reported driving at 35 mpg when he experienced this failure accompanied by an alert of the brake light.

Another folk reported that his brake assistance suddenly started working with no car ahead of it and it disrupted the entire process.

He feared that the brake system which was supposed to prevent crashes might just be the cause of it.

Although the S-Class has its issues, it’s not all bad. In fact, the Mercedes-Benz S-Class has its best and worst years.

2. Electrical Failure

This failure showed up in the recent version of the Mercedes-Benz S-Class model. Driving a luxury vehicle packed with complex electrical wiring may inevitably come with some faults.

This electric failure affected the use of the e-call system, especially in the S500 and S580 models.

This failure prevents passengers from calling emergency services when there’s an accident.

Another electrical failure that showed up majorly was that several applications that were supposed to be disabled during driving were not and it ultimately led to the distraction of drivers and an increased risk of a crash. 

This issue led to a recall for vehicles affected and about 1,239 vehicles were involved. However, this problem was not so severe as it was just a major flaw with the software system.

It can easily be rectified, as there aren’t many parts needed to fix the problem.

3. Tire Failure

Another issue that plagued the Mercedes S Class Benz was its Pirelli P zero Tire failure. This issue was particularly found in the 2022 models.

One owner reported that he experienced a complete blowout failure with the passenger’s side tires. He stated that he replaced it with the spare, but a week later; he experienced the same blowout failure again.

It is safe to say that the standard tires that came with the S-Class were below quality.

The owner had to take the pain of replacing the four tires while the vehicle had merely reached 2,000 miles. 

4. Structural and Body Problems

Driving a luxury SUV should not come with a structural problem because what then is the essence of its luxury?

Unfortunately, the S-Class seemed to have fallen short. It was reported that the model had many structural and body parts flaws.

Some folks complained that they experienced wind noise coming from the front windows, others reported that the doors were too heavy, and even worse, their door features refused to function.

This was simply disappointing for a model that was considered luxurious. 

Going further, the shattering of sunroofs has been a common occurrence with the S-Class and it was an issue that has resulted in serious problems. The major cause for this fatal flaw boiled down to the poor design of the company.

They failed to take proper steps to ensure a quality build. Lastly, the latest Mercedes models also had a minor problem with their front door windows.

It was shown that the window may clutter when put down. Disappointing.

5. Diesel Leaks

The failure came on in the W222 models as they come equipped with the OM651 engine. This engine was used in model years before 2017, but they predominantly found this leakage problem in the 2014 model.

The failure of this compartment was linked to the O-ring seals between the timing chain tensor and the engine block.

The O-rings are essentially a sealing agent. They are made of elastic to keep fluids and oil from leaking and without these seals, there is a big chance that leakage might occur. 

This failure led to a recall because this leakage posed a fire risk and could cause total damage to the engine. It is very important to check whether your vehicle was included in the recall before you purchase the 2014 model.

You should also check out some problems with Mercedes cars.

6. Overheating of the Wiring Harness

A wiring harness is the complete electrical system in a vehicle. It is the organized set of wires and connectors responsible for powering up the electric component in the vehicle.

However, the placing of this harness is essential as it could either help or damage the health of the electrical system.

Unfortunately, with the S-Class, it was shown that the wiring harness was located close to the exhaust system, which was a terrible idea. Even the alternator was positioned close to the exhaust system.

This led to a recall in 2016 because the electric wires were getting damaged due to the heat emanating from the exhaust.

Worse still, it also affected the transmission of the vehicle, as some owners reported that their transmissions suddenly shifted into neutral and it also lost their capacity to shift into ‘park’.

7. Automatic Transmission Problems

This problem was found with the two automatic transmissions, the 7G Tronic and the 9G Tronic of some of the S-Class models.

The former came into the limelight in models before 2017, while the former was featured in the 2017 to 2020 models.

However, these transmissions seemed to carry along some flaws, like rough downshifting and upshifting of the gears.

This made the vehicle difficult to maneuver for owners. Another problem that came up was the defects in the valve body and conductor plate.

The valve body is the brain of an automatic transmission that is responsible for putting out signals to engage the clutch to shift at the appropriate time. At the same time, the conductor plate is simply placed on the valve body of the transmission. 

The flaws were so widespread, and they needed to be resolved because owners were severely affected. Thankfully, shortly after, the company released a system update that resolved this transmission problem.

8. Engine Rattle

These rattling sounds were common with the S500 and S400 Mercedes models. This sound was linked to a faulty secondary chain tensioner and insufficient oil pressure in those tensioners.

When a chain tensioner fails, the valves don’t open and close at the appropriate time, which leads to a loss of compression, and then the engine misfires.

When the engine misfires, it could lead to a rattling sound after the start-up of the engine.

The company released a service bulletin to educate the drivers, and they also replaced the chain tensioner and installed a check valve in the supply bores. 

9. Seatbelt Problems

Another known problem of this vehicle was in relation to its seal belts. The problem was so bad that they had to issue a recall as it posed a safety risk.

Some owners stated that the seatbelt handover was not retracting. Another stated that the front passenger’s belt tensioner was not deploying as it failed to lock them in their seats when there was a sudden stop.

The pre-safe feature was also faulty. This component was a crucial safety tool, as it employs a series of sensors to detect the instability caused by the braking system.

The company had to resolve this issue before it led to bigger problems.

General Pros and Cons of the Mercedes-Benz S-Class

Below is the list of the strength and weaknesses of the S-class models.

Pros

• Advanced power engine 
• Sleek design
• High-end interior controls
• Dynamic handling

Cons

• Pricey options 
• Cargo space is limited

What Is the Resale Value of the Mercedes-Benz S-Class?

According to CarEdge, the Mercedes Benz S class has a depreciation value of 46% after 5 years and a resale value of  $68,852 after a 5-year period. However, these prices vary depending on the trim.

Below is a table highlighting the depreciation value of the Mercedes Benz S-Class.

What Do the Reviews Say?

According to J.D. Power, the 2022 Mercedes-Benz S-Class archives 78 out of 100 for its reliability.

Also, according to AutoExpress, the S-Class is one of the undisputed kings of saloon cars, giving it an overall rating of 4.0 out of 5.

This vehicle features many of the company’s latest innovations. It is extremely refined and technology-laden, ranging from its augmented reality navigation to its 3D digital display.

The Mercedes is impressive in its gas mileage as it claims a range of 32.4-34.5 mpg for the standard-wheelbase S500 models, but its longer version reduces this range down to 32mpg or less.

The other models, like the S350d, achieve a mixed consumption of 40.4-42.8mpg.

Lastly, the Mercedes S-Class is equipped with tons of safety features, and most of these features are largely reliable.

Go Back: Problems for all Mercedes models.

Was this article helpful?

ⓘ  The information in this article is based on data from National Highway Traffic Safety Administration (NHTSA) recall reports, consumer complaints submitted to the NHTSA, reliability ratings from J.D. Power, auto review and rating sites such as Edmunds, specialist forums, etc. We analyzed this data to provide insights into the best and worst years for these vehicle models.