Mercedes-Benz W222 Problems: Writing these “common problems” articles is one of our specialties here on LifeOnFour. And as you might have noticed we love getting deep into these problems as we have shown in our review of the W221 S-Class and our W220 common problems article. Today, however, we are looking at the sixth generation of the Mercedes S-Class which is commonly known as the W222 S-Class. The W222 S-Class was produced from 2013 to 2020. Design-wise, the W222 S-Class shares design elements with the W205 C-Class and the W213 E-Class. But apart from the design, the S-Class is still on another level when it comes to features, comfort, and premium materials. But as we learned in the past, the more features there are and complicated technology, the more problems arise.
If you are looking to buy a W222 S-Class, make sure you continue reading this review of the common Mercedes-Benz W222 Problems.
Major Mercedes-Benz W222 Problems
OM651 diesel engine oil leaks (4 Cylinder diesel engine – pre-2017 model years)
We talked about the OM651 diesel engine before (see this article: OM651 engine problems) and the W222 S-Class features the OM651 engine both in a standalone version or paired with a hybrid system. The OM651 engine was only present in model years before 2017 and it is the only diesel engine in the offering with 4 cylinders.
One of the Mercedes-Benz W222 problems is connected to the OM651 diesel engine. The O-ring seal between the timing chain tensioner and the engine block in the 2014 model year was prone to leaking which posed a fire risk and endangered the well-being of the engine. Mercedes issued a recall and fixed this issue but if you are buying a 2014 model year W222 with the 4-cylinder OM651 engine, make sure this problem has been taken care of.
S350 wiring harness overheating recall
Having wiring harnesses close to the exhaust system is never a good idea. This exact thing happened to certain W222 S350 vehicles. The wiring harness of the transmission and alternator was positioned dangerously close to the exhaust system. The heat that emanates from the exhaust could potentially damage the wiring and cause significant damage. If the damage already occurred, the transmission would shift into neutral while driving and it lost the capacity to shift into Park. Mercedes issued a recall in October of 2016 for the affected S350 models.
Airmatic Suspension problems
Just like the W221 and the W220 S-Class before, the W222 S-Class features the Airmatic air suspension system. Even Though there are currently no significant reports of extraordinary Airmatic failures on the W222 S-Class, it is good to remember that no air suspension is cheap to maintain and service as these cars become older and have higher mileage. Airmatic components are expensive to replace. To learn more about Airmatic air suspension problems, check out our Airmatic problems and solutions article!
Automatic transmission problems
The W222 S-Class features two automatic transmissions, the 7G Tronic and the 9G Tronic. The 7G automatic transmission was featured in the pre-facelift (model years before 2017) and the 9G transmission in the 2017-2020 model years.
The 7G, despite being a good and proven transmission at this point, did cause some problems with hard downshifting and upshifting from 2nd to 3rd gear. As you can see in this W222 forum thread, this is considered a widespread issue that is now resolved by a simple software update. After the update, the issue is resolved. The 722.9 7G transmission used to be known for defects in the valve body and the conductor plate but those issues are resolved in the W222. Aside from some rare cases, the W222 has no transmission problems.
Despite being fairly new, the 9G Tronic came with fewer problems than the 7G. There are reports of occasional shift solenoid failure but these cases are rare. Both transmissions are reliable and will easily last a long time with the right maintenance.
2017-2020 OM656 and OM654 diesel engine problems
These two diesel engines are fairly new and they are both generally considered to be unproblematic. However, since the introduction of the V6 OM656 engine in the W222 S-Class reports of failing tandem pumps. A tandem pump is a low-pressure fuel pump that also includes a vacuum pump. Owners who experienced a tandem pump failure were faced with major loss of power and even brake system failures. This issue is being talked about more and more as these engines come out of warranty. The cost of repairs is approx. 5000$. Read more about this issue in this forum thread of Mercedes Club UK.
The 4-cylinder OM654 engine on the other hand has been performing spectacularly. There are rare occurrences of premature wear of rocker arms. We wrote more about this issue in our review of the W213 E-Class.
In January of 2022, both diesel engines in the W222 S-Class were recalled due to a potential leak between the coolant pump and the vacuum circuit. If the coolant was to enter the vacuum circuit, there was a risk of fire due to the increased temperature of these components.
S560 oil leak problem and recall
In 2020, Mercedes issued a recall on faulty engine oil plugs. The oil plugs fitted to the 2018 and 2019 W222 S560 models were made out of subpar material which was not suited for the big pressure and engine loads during driving. A failed oil plug could not only drain the engine of oil and cause complete engine failure but also endanger other drivers with the oil leak. If you are buying a 2018 or 2019 W222 S560, make sure the car is not affected by this recall or that it had the oil plugs replaced.
Minor Mercedes-Benz W222 Problems
S550, S500, S400 Petrol engine problems
Both the M276 V6 petrol engine and the M278 V8 petrol engines are considered to be excellent. With regular maintenance, there should be no issues at all and many are praising these engines as the last great Mercedes petrol engines in the electric outlook of the future. Both engines do have problems with the chain tensioners and the check valves, but this is mostly a problem in high-mileage vehicles. Independent Mercedes mechanics are well aware of this issue so fixing it is not as big of a problem as it once was. Both engines also suffer from carbon buildup in the intake manifold which is nothing new in the world of modern engines. Read our article on engine carbon buildup to see how you can prevent it or get it fixed. There are also reports of various oil leaks, but nothing notorious like the infamous oil cooler leak on the OM642 diesel engine for instance. With age, seals and gaskets give out and oil leaks are the result, nothing surprising there.
Oil leaks due to incorrect oil line material
Another recall of the W222 S-Class was about cars made between August 2018 and the end of April 2019. The affected vehicles came with oil lines that were made out of material that did not meet the specs. As you can imagine, this could lead to potentially dangerous oil leaks.
S500 and S400 and S500 Hybrid engine rattle
Due to a faulty secondary chain tensioner and a lack of oil pressure in those tensioners, a number of owners of early model year W222 Hybrid models were complaining about a rattling noise after the start-up of the engine. This affected both the S400 & S500 (M276 engine + hybrid) and the S500 with the M278 engine and hybrid drive. Mercedes released a service bulletin and replaced the faulty components and installed a check valve in the oil supply bores.
Start/Stop system malfunction
Like other Mercedes models, the W222 also experiences problems with the start/stop system. In almost 100% of the cases, a faulty auxiliary battery is a culprit behind the problem.
Problems with oil leaks near the turbocharger
A number of owners on owners forums are reporting oil leaks at the inlet and outlet oil lines of the turbochargers. This is a problem with all W222 variants.
Body and interior problems
S-Class seatbelt-related problems
During the time of production, there were several recalls in connection to the W222’s seatbelts and other safety features. This includes:
- Seatbelt handover arm not retracting (MB issued a recall)
- Front passengers seatbelt tensioner not deploying (MB issued a recall)
- Improperly made front seatbelt squibs (MB issued a recall)
- Pre-Safe feature malfunctions and front seatbelt engagement detection problems (MB issued a recall)
When buying a W222 S-Class make sure it had all of the recalls taken care of. There were a lot so it is worth your time and money doing so.
Electronic Mercedes-Benz W222 Problems
Comand system problems
A number of owners are reporting random problems with the Comand infotainment system of the W222 S-Class. Problems include the screen going black, navigation problems, and random occurrences of the Comand system shutting off. These problems are not common, but we did detect them.
Radar assist control unit failure
Vehicles made in the second quarter of 2019 were prone to failure of the radar assist control unit. As the unit failed, so did the Active brake assist feature which increased the chances of an accident. Mercedes issued a recall campaign and resolved the issue.
Future Electronic Mercedes-Benz W222 Problems
When buying a car like the W222, keep in mind that as these cars age, there are going to be a lot of electronic problems. After all, this car has over 100 electric motors that keep all the innovative features alive. All of these systems and motors and modules will be a failing point as the car ages.
Magic Body Control problems
The W222 S-Class was the first Mercedes-Benz that features the new Magic Body Control suspension which is the next step in the evolution of the well-known ABC (active body control) hydraulic suspension. The main difference between the two is that MBC recognizes the road conditions (potholes, speedbumps) and adjusts the hydraulic suspension preemptively. In contrast, the older ABC suspension reacts after it has hit a pothole or a speedbump. The MBC hydraulic suspension is considered genius, it is so good that we rarely see as much praise for suspension components as we see for the MBC suspension.
However, if we are realistic and judging by how expensive to service the older ABC suspension is, we can assume that Magic Body Control suspension will be just as expensive to fix if not more. Only go with cars that have MBC if you can afford the long-term maintenance. As of now, no extraordinary problems have been troubling this new suspension.
eCall system problems
W222 S-Class cars made between 2018 and 2020 were prone to software issues which resulted in the deactivation of the eCall safety system that allows the passengers to call emergency services.
Frequently asked questions
Is the W222 S-Class reliable?
In our opinion and the currently available data, we would say that yes, the W222 S-Class is definitely amongst the most reliable high-end luxury cars on the used car market today. Based on the number of advanced features and electronics, despite being almost 10 years old, the W222 has a good record of reliability.
Which is the most reliable engine in the W222 S-Class?
If we had to choose, our choice would be either the M276 V6 engine or the M278 V8 engine that was present in the pre-facelift versions of the W222. Both engines have a long history of improvements which made them the perfect choice for the W222 as they both come with many of the major problems already resolved out of the factory.
The most common Mercedes-Benz W222 Problems include:
- Engine oil leaks (especially on diesel engines)
- Wiring harness overheating problem
- Seatbelt related issues
- Hybrid engine rattle problems
- Electronic and Comand infotainment problems
- Radar assist problems