Mercedes C-Class W205 Which Version Is More Reliable?

Anyone looking for a premium used car at a fair price of 18-20,000 euros can choose the Mercedes C-Class W205. But which engine is more reliable?
 

There are many customers who want a premium car but can’t afford the price of a new one. For example, the cheapest Mercedes C-Class W206, the C 180 version, costs a minimum of 45,202 euros and has a turbocharged four-cylinder 1.5-litre engine under the bonnet that develops 170 ps and has an integrated 23 ps starter generator. Likewise, the cheapest diesel, the C 200 d with a 2-litre 163 hp turbodiesel engine with an integrated 23 hp starter generator costs a minimum of 48,058 euros. And the list of options is long and can raise the price even further.
 
But at around 18-20,000 euros, you can find the former generation Mercedes C-Class, the W205, produced between 2014 and 2021. It was available with 4- and 6-cylinder diesel and petrol engines but also with the fabulous 4-litre AMG V8, which is no longer available in the new generation. But which engine to choose?
 
The OM651 diesel engine is the most reliable
The smaller displacement 1.6-liter Renault-derived diesel under the bonnets of the C 180 d and C 200 d were not as reliable as the Mercedes engines. Until October 2018, before the facelift, the best-selling engine was the 2.2-litre OM651 diesel. This engine is also the best choice because it is the most reliable and the easiest to maintain. Although the timing chain is located behind the engine, contrary to the position of the competition, the effort to replace the timing chain is less. It has a lock link and can be opened and replaced with the gear installed.
 
In contrast, the OM654 motor that replaced the OM651 in 2018 is not as reliable. It is incredibly economical and eco, meeting Euro 6d Temp standards, but has the same problems the BMW 2-litre diesel had in 2014/2015. The timing chain is undersized, tends to elongate, and, in the worst case, breaks. Regardless of the car’s history, the number of engine failures due to timing chain problems on the OM654 is increasing.
 
The Mercedes C-Class W205 features a very good quality interior, a premium sound when closing the door, and the plastic elements do not rattle or make any parasitic noises. The drive train is agile thanks to smooth and direct steering and is also very comfortable. The braking system is also remarkable, ensuring short braking distances.
 
But there are also some rust problems at the carrier of the rear axle. Rust appears under a dimensionally stable powder coating and is not noticeable in the initial stage but only later. But there is a handy solution for this, and that is to apply a rust protection coating.
 
Considering the problems with OM654, our choice from the C-Class W205 series is the C 220 d produced between July 2016 and October 2018 in the 190 hp version with 9-speed automatic transmission. If the gearbox is properly maintained and oil changes are done on time, the gearbox has impressive reliability, shifts smoothly, and allows for incredibly low fuel consumption thanks to the wide range of gear ratios.