The Mercedes-Benz CLS C219 came on the market in 2004. It is the first generation of this model. Already in 2006 there were major technical upgrades that improved reliability. In 2008 it underwent a mid-life restyling that introduced other technical and design innovations. Externally the headlights, the taillights and the rear-view mirrors have changed. In 2010 it was replaced by the next generation Mercedes-Benz CLS C218. Let’s see the Mercedes-Benz CLS C219 review with the most important information, faults and common problems.
Table of Contents
- Impressions and Description
- Reliability and Issues
- Engines and their Problems
- Conclusions and Advice & Tips for buying used
Impressions, Interior and Comfort
The market release of the Mercedes-Benz CLS C219 was an important event for the automotive world. For the first time, a body type appeared which is defined as a 4-door Coupé. This particular model is based on the Mercedes-Benz E-Class W211, but ranks higher up the manufacturer hierarchy. It is a high-class car that sits between the E-Class W211 and the S-Class W221. Only powerful engines and automatic gearboxes were mounted on the Mercedes-Benz CLS C219.
Over the entire production period, 170,000 units were created. On the second-hand market they can now be found at low prices. These are almost always very well-equipped cars, with lots of options and modern technologies (for that period). After so many years all this can begin to give different problems.
In this article we will see if the maintenance costs will not be exaggerated to use a similar car.
Platform and Body
The platform of the Mercedes-Benz CLS C219 is the same as used on the Mercedes-Benz E-Class W211. It is a platform that allowed the installation of many modern systems (for that period), but the basic structure remains the same: engine installed longitudinally and rear wheel drive. However, all-wheel drive has never been mounted on the CLS C219, although it is present on the E-Class W211.
The front suspensions are with high wishbones with a semi-virtual steering axis by splitting the joint of the lower triangle with two separate arms, the rear ones are multilink with 5 links. Optionally, the Airmatic Dual Control air suspension could be installed.
Mercedes-Benz CLS C219 is a very nice car with a sporty body design, low roofline and frameless door windows. It is clear that this car is made to attract attention. You can see right away that this is a luxury car.

Rear of a facelifted Mercedes-Benz CLS C219
Aesthetically, the car is attractive, both before and after the restyling, especially in the more equipped versions.
Mercedes-Benz CLS C219 is present in only one body version. Although it is based on the same platform as the E-Class, it has slightly different dimensions (it is longer, wider and lower). The German car has a length of 4902 mm, a width of 1873 mm and a height of 1389 mm. The wheelbase is 2855 mm. The weight of the car varies from 1655 to 1845 kg depending on the version.
For the traditional Coupé and Cabriolet versions, the CLK class has been dedicated.
Comfort and Practicality
Despite the large dimensions of the car, due to the particular shape, the internal space is not really that much. In front anyone will be able to position themselves comfortably, even in the rear seats there is enough space, but tall people may feel a little lack of space in the head area. One thing that can be annoying while traveling are the small mirrors that can be not so informative.
The trunk/boot volume is 505 litres, this is a good result for this class of car. The strong points of the model are the quality of the materials and the great driving comfort, but all this is normal for a high-class Mercedes.
The comfortable suspensions offer great driving pleasure, especially the Airmatic pneumatic ones which can guarantee both good road stability and great softness. With the standard suspension however, the Mercedes-Benz CLS C219 may feel a little harsh on bad roads.
All together it makes the Mercedes-Benz CLS C219 an extremely comfortable and enjoyable car both in and out of town. Even longer journeys shouldn’t be too tiring.
Interior and Equipment
The interiors are very luxurious with an elegant and harmonious design, the lines are soft and welcoming. The large wooden inserts are particularly pleasing. The materials used in the interior are really of excellent quality. The ergonomics are very good and the feeling of luxury does not leave the passengers. It could not be otherwise given the great price they were asking for this model.
The materials are also quite resistant over time, if treated well. On well maintained cars, there are no serious signs of wear before 100 – 150,000 km (60 – 95 k miles). Among the first elements to show signs of wear will be the driver’s seat and steering wheel. The latter suffers especially when used by a woman with long nails or rings.
If the car is equipped with steering wheel heating, the leather on the steering wheel deteriorates much faster. The reason is the high heating temperature which dries out the leather and it arrives in bad condition already at 100,000 km (60 k miles).
The good part is that all traces of wear and tear present in the cabin can be eliminated if desired. Some pieces can be replaced, others can be repainted or restored.
The soundproofing is very good and the interior remains silent in any situation.
As already mentioned, Mercedes-Benz CLS C219s are generally very well equipped. In addition to the aforementioned air suspension, you can have adaptive cruise control, the monitoring system for non-visible areas, webasto (autonomous heating), seat heating and cooling, ILS adaptive lights, light and rain sensors, parking sensors, mirrors with automatic dimming and much more.
You can also have a good multimedia system. It’s actually old now, so it can’t fully satisfy modern needs. Generally, however, it can guarantee high quality audio.
Safety
Crash safety is quite good. It should be on the same level as the Mercedes-Benz E-Class W211. To decrease the risk you need good tyres. Tires are almost the most important thing for safety on the road.
Reliability and Issues
Gearbox and Transmission
As already mentioned, only the automatic gearbox was mounted on the Mercedes-Benz CLS C219. This could be 5-speed (5G-Tronic of the 722.6 series) or 7-speed (7G-Tronic of the 722.9 series).
5G-Tronic automatic gearbox
The old 5-speed automatic transmission is the 5G-Tronic of the 722.6 series. It is a very interesting and widespread automatic transmission.
In general, the 722.6 gearbox mounted on the Mercedes-Benz CLS C219 is already the one that has undergone the most modernizations and therefore no longer has its childhood problems. Reliability is good and defects are quite predictable.
Due to the partial lockup of the torque converter, the lockup system of the converter can already be found worn out at 150,000 km (95 k miles) on some cars. At this mileage it usually happens on cars with powerful engines or those used aggressively. With quieter use, the torque converter will fail no earlier than 250 thousand km (155 k miles). The first signs of wear will be rough gearbox operation the inability to engage mode “D” until the car warms up. At first the problems only show up when the gearbox is cold, but as the situation gets worse they will also feel when the gearbox is hot.
After 150 – 200,000 km (95 – 125 k miles), in addition to overhauling the torque converter (due to the wear just mentioned), it may be necessary to change the solenoids and clean the hydraulic block where accumulations of dirt could be found if the oil has not been replaced regularly. For the same reason, the control board can also suffer and the speed sensors can fail. Many do not replace the gearbox oil at all and as a result its life is shorter than in gearboxes on which it is replaced regularly.
One of the most important things is to change the oil every 40 – 60,000 km (25 – 35 k miles) together with the filter. This will improve the operating conditions and therefore lengthen the life of the unit. If the gearbox breaks down, the cost of repairs will be large. If treated very well, it can even go 200 – 300,000 km (125 – 185 k miles) without major problems.
7G-Tronic automatic gearbox
The 7-speed automatic transmission is the 7G-Tronic of the 722.9 series.
The 7-speed gearbox of the 722.9 series is less reliable (at least the versions of the first years of production). It has a non-optimal general construction, the hydraulic block always tends to overheat, the oil tends to get dirty quickly and the duration of the clutches is low. Added to all this are some “childhood” problems in the first years of production.
The problems mentioned generally already appear at low mileage and on many cars the hydraulic block and torque converter have already been changed under warranty and in some cases the gearbox was even completely replaced.
The 722.9 series automatic transmission has undergone various modernizations and there have been various recalls. Over time, the situation has improved.
The cars most at risk are those produced before the restyling (especially if they have not participated in the recalls and modernizations). After the restyling the modernized gearbox was mounted which after fixing most of the problems can be considered quite reliable. The same updated gearbox was also fitted to the Mercedes-Benz E-Class W212 and Mercedes-Benz C-Class W204.
High operating temperatures ruin the electronics, solenoids and hydraulic block. The first interventions may be necessary even after 100,000 km (60 k miles).
As already mentioned, the complex electronic system suffers greatly due to the high operating temperatures. On the other hand, modern electronics offer the possibility of diagnosing the gearbox well. A good mechanic will be able to discover many problems just by connecting the computer and reading the various parameters.
The torque converter locks up very aggressively (acts almost like a wet clutch) and is almost always at least partially locked. This causes accelerated wear of the locking system. As a result, due to heavy wear, the oil becomes heavily soiled with wear fragments. Dirty oil can lead to the destruction of the oil pump (it can even happen at 100,000 km or 60 k miles) and accelerated wear of the entire unit.
The positive part of the 722.9 automatic gearbox is the very resistant mechanical part which is able to withstand the great powers of the big engines well.
A modernized 722.9 automatic transmission can live for many miles if well treated. To lengthen life, it is advisable to replace the oil regularly (at least every 40 – 60,000 km or 25 – 35 k miles), fit a lower temperature thermostat, add a large heat exchanger and add an external oil filter. These recommendations are ultimately useful for any modern automatic transmission (they are all quite overloaded).
Drivetrain and Transmission System
We have already mentioned that the Mercedes-Benz CLS C219 are only available with rear-wheel drive. The drivetrain is quite reliable. The cardan shaft (drive shaft) lives at least 150 – 200 thousand km (95 – 125 k miles), the rear differential and the axle shafts only need periodic checks, maintenance of the correct oil level and protections in good condition.
Suspensions, Steering and Brakes
The Mercedes-Benz CLS C219 can have standard suspension or Airmatic air suspension. The pneumatic ones are more pleasant to use. On the other hand, when it comes to maintenance costs and reliability, the standard ones win out.
The standard suspension is reliable and long enough. Maintenance prices are high, but not outrageous. The rear arms are quite durable, while the front ones last less, especially if you drive on bad roads. For each front wheel there are 2 arms. When it comes time to change them there will be a relatively large amount to pay.
As usual, among the first elements to give way are the stabilizers. For the rest, on roads in good condition there should be no problems for at least 200 – 250 thousand km (125 – 155 k miles).
However, the situation is different for the Mercedes-Benz CLS C219 equipped with Airmatic air suspension. Before a possible purchase, you must check very carefully the functioning of the latter. This applies especially to cars from the first years of production. On these, in addition to the mechanical elements which wear over time, there could also be problems with the control electronics and various sensors.
The air suspension must always be kept under control and possible problems must be anticipated. If, for example, one or more air cushions suddenly start to leak, circulation can become very difficult. Air cushions live approximately 70 – 150,000 km (45 – 95 k miles). It all depends on where and how the car is used. In places with a harsh climate, on dirty roads with dust and chemical reagents, the life of the air suspension will be minimal.
In hot, dry places with clean roads, the suspension will live for many miles. Care also helps a lot to extend the life of the air suspension. It is important to always wash the elements at risk and possibly also lubricate them with various protective substances. It is also possible to mount additional protections.
Even with attention and care, air suspension is unlikely to exceed 200,000 km (125 k miles). When the time comes to replace elements, spare parts from alternative manufacturers can be fitted to save money. Obviously it is better to opt for high quality manufacturers (for example Bilstein). The interesting thing is that the spare parts of some alternative manufacturers are even more durable than the original ones.
If there are problems with the air suspension and the air leaks are large (for example if a cushion “explodes”), it will be better to deactivate the compressor by pulling the dedicated fuses. This will save the life of the compressor, otherwise it will run continuously until it wears out. If the leaks are small, you shouldn’t immediately think of a defect in the cushions. In fact, there could also be leaks from the various pipes or from the valve block.
Steering system
The steering system is simple, reliable and pleasant. Only the power steering pump does not live as long. The rack lives about 300,000 km (185 k miles) with small 16 – 17 inch rims, or 200,000 km (125 k miles) with larger rims.
Brakes system
The situation with the brakes is peculiar. Since the Mercedes-Benz CLS C219 is based on the Mercedes-Benz E-Class W211, it also inherited its weaknesses. The SBC electro-hydraulic brake system was fitted until 2006. The system is convenient because it allows more effective braking, but it is programmed for a limited number of uses. When the maximum braking limit is reached, the system locks the brakes and asks you to go to the workshop.
The duration of the SBC system obviously depends on the driving style and the type of road traveled (it lasts less on cars that only travel around town and brake often, it lasts longer on cars that only travel on the motorway and brake less). On average it doesn’t last more than 200,000 km (125 k miles). We will talk more about this system later.
After 2006 a simple brake system was installed, which does not cause any particular problems. The life of the discs and pads is good, but it all depends on the driving style. The pads last an average of 40 – 50 thousand km (25 – 30 k miles). The lifetime of the discs can be multiplied by 3 or even by 4.
Over the years, the brake fluid channels wear out. You have to be very careful and carry out periodic checks.
Electronics and Electrical System
The electronics of the Mercedes CLS C219 are very complex. Despite this, the electronics work well and shouldn’t cause any particular problems (as long as they’re new). Serious problems are generally caused by external factors: penetration of water that comes into contact with cables and control units, accidents that damage the system and interventions by not qualified people on the electronic system.
If moisture enters the engine fans control unit, they could “go crazy” and never stop. They will only stop spinning when the battery is completely discharged.
The situation is very critical if the water ends up in contact with the SAM control units. These have a central role and allow communication with the other control units and sensors scattered around the car. When a SAM ECU dies, it can also damage the other elements connected to it.
In addition to the SAM control units, there are also many other control units that control the large amount of systems. Virtually everything contains electronics. To understand the complexity, we can give the example of the wiper control unit which can lose its management firmware or be damaged in any other way. After replacement or repair, the ECU must be reprogrammed with the official Star Diagnose tool. The same tool will also be useful for replacing pads on pre-styling cars with SBC electro-hydraulic brakes. The SBC system is also a big weakness, but more on that later.
Other than SAM and SBC there shouldn’t be such expensive electronics problems. But the car is now old and the complicated electronics (especially on highly equipped cars) is starting to “go crazy”. There are many small problems that could appear and they are different on each car. In most cases these do not completely prevent the use of the car, but they can annoy a lot.
Failures of alternators, ignition coils, parking sensors, xenon headlight ignition modules, LED light modules, body level sensors and other “trifles” can happen.
The Command multimedia system was problematic before the restyling. Then it was modernized and became more stable. Among the most frequent problems is the one with reading the navigation CD. Many problems can be caused by the ingress of dust.
Before a possible purchase it will be useful to carry out a deep diagnostics, check the functioning of all the systems present, check the cables and their integrity (especially in critical points such as the doors) and look at the SAM control units. If you see traces of oxidation or humidity, it’s best not to risk it.
It happens to find the car with a completely flat battery even after a short stop. The reason is again the complicated electronics which could “suck” the current for various reasons.
SBC System
SBC (Sensotronic Brake Control) is an innovative electro-hydraulic brake system. This system is intelligent, it cleans the brakes and maintains them in good condition through various procedures, it emulates the effort on the pedal without transmitting shocks and vibrations, it is pleasant and does not make you tiring while driving, it brakes the car very well, but all this only when everything is in good order. The problem is that this system is not immortal and is designed for a limited number of braking operations. Once the maximum number of brakings has been reached, the system will have to be reviewed.
When it comes time to repair the system the error will pop up on the on-board computer. Initially the message will be written in white. Already here we need to start preparing the money. If you continue to use the car for a longer time, the message will turn red and the use of the car becomes dangerous. In theory the brakes should lock up and the gear selector movement should be blocked to prevent starting.
To replace everything you have to pay a lot of money. Some mechanics can fix it for a good price (hydraulic accumulator and pump repair), but good experts are rarely found. In some cases it is simply the fault of the dead battery. In fact, the operation of this system is ensured by a separate battery and there have been cases of brake system malfunctions due to a flat battery. This is exactly why you need to be careful and replace it in time.
As already mentioned, the presence of this system also makes it more difficult to replace the pads. To perform the work you need a specific tool – Star Diagnosis.
The SBC system was fitted to cars manufactured before 2006. Then, the Mercedes CLS C219 got a classic brake system and thus the problems disappeared. To lengthen the life of this system it is advisable to change the brake fluid regularly.
Other
Mercedes-Benz CLS C219 is well protected from corrosion. Small traces of rust can be found on cars used in places with a particularly severe climate. If, on the other hand, the traces of rust are large, the car probably suffered some accidents and then was badly repaired.
The paint is of good quality, but scratches still appear over the years and the initial shine is lost. Chromed plastics wear out relatively quickly.
As we have already said, the doors of the Mercedes CLS C219 have frameless windows, which means that each time the door is opened, the glass lowers slightly to release itself from the seal. These constant movements lead to relatively quick wear of the mechanism, especially on the driver’s door which is used more often. In the event of failure of the electric window mechanism, there is no need to rush to replace the whole mechanism. Generally it is sufficient to replace the cable.
Over time, the headlights become dull and need polishing. The reflective element inside also burns out after so many years and the intensity of the illumination is lost. Hella projectors or other projectors from alternative manufacturers can be purchased and installed without any problems.
The windshield wiper mechanism turns out to be quite fragile, over time, play appears and there will most likely be oxidation which will lead to malfunctions.
Engines and their Problems
Diesel engines list :
Version | Engine | Power | Top Speed | Acceleration | Fuel Consumption |
CLS 320 CDI | 3.0 l OM642DE30LA | 224 hp | 246 km/h or 152 mph | 7 s | 7,6 l/100 km
US: 30,9 mpg UK: 37,1 mpg |
CLS 350 CDI | 3.0 l OM642DE30LA | 224 hp | 246 km/h or 152 mph | 7 s | 7,6 l/100 km
US: 30,9 mpg UK: 37,1 mpg |
Petrol/Gasoline engines list :
Version | Engine | Power | Top Speed | Acceleration | Fuel Consumption |
CLS 280 | 3.0 l M272E30 | 231 hp | 245 km/h or 152 mph | 7.7 s | 9,8 l/100 km
US: 24 mpg UK: 28,8 mpg |
CLS 300 | 3.0 l M272E30 | 231 hp | 245 km/h or 152 mph | 7.7 s | 9,8 l/100 km
US: 24 mpg UK: 28,8 mpg |
CLS 350 | 3.5 l M272E35 | 272 hp | 250 km/h or 155 mph | 7 s | 10,1 l/100 km
US: 23,2 mpg UK: 27,9 mpg |
CLS 350 CGI | 3.5 l M272DE35 | 292 hp | 250 km/h or 155 mph | 6.7 s | 9,3 l/100 km
US: 25,2 mpg UK: 30,3 mpg |
CLS 500 | 5.0 l M113E50 | 306 hp | 250 km/h or 155 mph | 6.1 s | 11,3 l/100 km
US: 20,8 mpg UK: 24,9 mpg |
CLS 500 | 5.5 l M273E55 | 388 hp | 250 km/h or 155 mph | 5.4 s | 11,8 l/100 km
US: 19,9 mpg UK: 23,9 mpg |
CLS 55 AMG Kompressor | 5.4 l M113E55ML | 476 hp | 250 km/h or 155 mph | 4.7 s | 13,6 l/100 km
US: 17,2 mpg UK: 20,7 mpg |
CLS 55 AMG Kompressor Performance | 5.4 l M113E55ML | 476 hp | 300 km/h or 186 mph | 4.7 s | 13,6 l/100 km
US: 17,2 mpg UK: 20,7 mpg |
CLS 63 AMG | 6.2 l M156E63 | 514 hp | 250 km/h or 155 mph | 4.5 s | 14,5 l/100 km
US: 16,2 mpg UK: 19,4 mpg |
CLS 63 AMG Performance | 6.2 l M156E63 | 514 hp | 300 km/h or 186 mph | 4.5 s | 14,5 l/100 km
US: 16,2 mpg UK: 19,4 mpg |
No weak engines were put on the Mercedes-Benz CLS C219. In fact, the range starts from the 224 horsepower diesel.
Diesel Engines
3.0 l V6 CDI OM642 diesel Engines
The OM642 3.0 L CDI V6 engine is a well made engine, it has been produced for many years and has received great popularity.
The 3.0 l diesel engine of the OM642 series performs very well. Someone calls it the best choice for Mercedes-Benz CLS C219. It has good reliability, is long-lived, has low fuel consumption despite having good power and has few weak points.
This 3.0 l was Mercedes’ first diesel V6. It is a modern and complex engine, with an aluminum cylinder block and cast iron liners, aluminum heads with hydraulic compensators, a complex Common Rail injection system with piezoelectric injectors, a turbine with variable geometry and much more.
But don’t think it’s totally perfect. Of course, the great complexity also increases the number of possible problems and defects. At large mileages you must be prepared for the expensive repair of the injection system, turbine and intake manifold. Timing chain lengthening is almost inevitable after 200 – 250,000 km (125 – 155 k miles).
Among the most famous problems that can happen at smaller mileages are leaking heat exchanger gaskets. New parts are cheap, but due to the inconvenient location, replacement work will be expensive.
Engines with heavy oil leaks are encountered. Plus, the oil pump isn’t too reliable. Both of these aspects must be kept in mind, the engine cannot handle oil pressure losses well and in these conditions the bushings can fail.
On the 3.0 l diesel you have to be careful not to overheat the turbine. If it has become very hot, wait for it to cool down before turning off the engine. In general, you have to treat it well since a new turbine costs a lot.
Otherwise the OM642 engines are still very reliable. Thanks to their good characteristics in terms of power, reliability and consumption, they have been mounted on many models of the brand. It can also be found on: Mercedes-Benz GLK X204, Mercedes-Benz ML W164, Mercedes-Benz E-Class W211, Mercedes-Benz E-Class W212 and many other models.
Knowing the weak points and taking care of these units, it is possible to reach even 450,000 km (280 k miles) without fatal defects. Badly treated engines, on the other hand, will give serious problems already at 200,000 km (125 k miles).
There may be the typical problems of modern diesels. We’re talking about the EGR valve getting dirty and stopping working and the DPF filter getting clogged and causing problems. These problems mostly occur on cars used in the city.
Petrol/Gasoline Engines
M272 and M273 Engines
The 3.0 l M272 and 3.5 l M272 engines are mounted from the M272 family. The 5.5 l is mounted from the M273 family. The problems are about the same for all of these engines.
These engines may have problems with the ECU. The reason for the malfunctions of the control unit are the high temperatures under the hood which lead to a loss of impermeability and consequently oxidation. Driving with a malfunctioning control unit can also cause damage to the mechanical parts of the engines which are quite fragile. A new control unit can cost a lot. In addition, the price of the work for the reprogramming will have to be added.
Other weak points of the petrol engines of the M272 and M273 series are: small longevity of the mechanical parts, short-lived timing system and its high cost, problematic intake manifold, weak catalytic converter, occurrence of oil leaks and the risk of occurrence of scratches on the cylinder walls. These units also gave problems to the owners of Mercedes-Benz E-Class W211 and Mercedes-Benz ML W164.
If the timing chain is not changed at the right time, there is a risk of damaging the balancer shaft on V6 engines and the chain pads on V8 engines. To change the balancer shaft, the V6 engine will have to be extracted. To replace the pads on the V8, you will need to disassemble the cylinder head. In both cases the cost of the works will be very high.
The entire timing mechanism must be replaced if there is wear on the balancer shaft gears on V6 engines and on the idle gear on V8 engines. On some engines this can happen as early as 100 thousand km (60 k miles).
Furthermore, overheating can occur due to a dirty cooling system and broken fans. All of this can lead to detonations and damage to the cylinder walls which in turn lead to oil consumption. A consumption of around 1 – 2 liters per 1000 km (600 miles) can be reached. This consumption is also accompanied by a more or less evident smoke. The easy appearance of scratches is given by the use of Alusil as a material for the surface of the walls. Alusil does not tolerate any kind of dirt. To avoid problems you need to change the oil often, avoid overheating and avoid driving with dirty air filters, worn catalytic converters or intake manifold.
Given the large repair costs, many people continue to drive for a long time just by adding the necessary oil. To repair these units there is often the need to extract the engine and this leads to an increase in the cost of the work.
The engines mounted on the Mercedes-Benz CLS 350 CGI versions are equipped with direct injection. To the problems already mentioned are added those with short-lived ignition coils and various problems typical of direct injection (especially if fuel that is not of the highest quality is used).
M113 Engines
The 5.0 l and 5.4 l are mounted from the M113 family. Engines of the M113 series can be called the most reliable among gasoline ones. They are robust and long-lived units, but obviously they are not ideal. Over time, the extended timing chain and the intake manifold will need to be changed (around 200,000 km or 125 k miles). The same goes for valve stem seals and other worn seals. Crankshaft pulley failures are frequent.
Engines may have problems with crankcase ventilation and piston rings. These little problems can lead to an increase in oil consumption. Also there may be oil leaking from under the valve cover and from the oil cooler. To have a leak-free engine it is important to periodically replace the gaskets and clean the crankcase ventilation system. Furthermore, it is advisable not to increase the engine revs up to the red zone of the rev counter.
These engines generally do 250 – 300,000 km (155 – 185 k miles) without major problems (when used and treated correctly). Among the weakest parts we can mention the catalytic converter which over time could cause problems and need to be replaced. For the long life of these engines it is advisable to change spark plugs and oil regularly.
M156 Engines
The M156 series engines are those mounted on the CLS 63 AMG sports versions. These are sports engines that are not exactly very reliable. In fact, American buyers have denounced the brand twice, complaining of the insufficient reliability of these engines.
The big engine fitted to the AMG sports versions is fun and interesting. If treated well and cared for carefully, it could even live for a relatively many miles.
The problems are given by the use of unsuitable materials in some points, which lead to a loss of resistance (for example in the case of the camshaft). In addition, scratches on the cylinder walls can appear on these engines over time. Even the cooling system is not effective enough for this big engine, especially in summer.
Conclusions and Advice & Tips for buying used
Mercedes-Benz CLS C219 is a very beautiful, interesting, luxurious and attention-grabbing car. It has a certain charming elegance. Obviously the sensations that a car gives are purely subjective, but this model can also offer a good level of comfort and pleasant emotions.
The car may need some investments. It would be useful to have a good reserve of money to invest in case of problems.
At the time of market release, the Mercedes-Benz CLS C219 had no direct competitors. Similar cars are: Mercedes-Benz CLK (classic Coupe and Cabriolet), BMW 6 Series E63/E64 (2-door Coupe and Cabriolet) and Audi A7 (which, however, only arrived in 2010 and is in fact a competitor to the later Mercedes-Benz CLS C218). Smaller, but very similar in structure are the Volkswagen Passat CC and the Audi A5.
Sedans of similar size can also be seen as competitors: the sister Mercedes-Benz E-Class W211, BMW 5 Series E60, Audi A6 C6, Volvo S80, Peugeot 607, Lexus GS and others of the same type.
The most important thing is to find a car in good general condition.