2022-2024 Mercedes-Benz C-Class AMG C 43 2.0L Turbo Engine (M139): Problems, Longevity, and Specs

If you have over $60,000 to buy a new car and you don't want a huge vehicle, the C-Class Sedan from Mercedes may be a good option. If you think it's expensive for a simple sedan, think about the AMG C 43 version that offers the most powerful engine in the model and seems to be a sports car hidden in the simple body design.

Today, I will tell you about the 2.0L Turbo engine that powers the C-Class AMG C 43 and makes it a really special vehicle with all that excessive power and torque. The engine is wonderful but, like all high-performance units, doesn't seem to be extremely durable. I've already told you about other C-Class engines and this one will close the series of articles about this model.

Key features and my opinion about the engine

• Production years:2019-now
• Average lifespan of M139:160,000-190,000 miles
• Fuel supply type:combined injection (direct+port)
• Power range:365-476 hp
• Fuel efficiency:average
• Engine block material:aluminum
• Engine reliability score:medium
• The most common problems:engine is very demanding to fuel quality, coolant leaks, turbocharger pipes dying, oil pump is driven by a weak belt.

What should you know about the C-Class AMG C 43 engine?

You may wonder that the C300 version of the C-Class also has the 2-liter turbocharged engine but it's far from being performance-oriented. The 2-liter engine that you will find under the hood of the AMG version offers over 200 horsepower from every liter of the engine displacement and that's huge!

Of course, you will need to pay with the longevity for such a performance, but this is something you should expect from probably every engine in this class. If you want exclusive power and unbelievable speed, you shouldn't expect your new vehicle to last 200K miles even if this is claimed by the manufacturer.

Here's what you should know about this engine:

• this is the 2.0L 4-cylinder turbocharged M139 engine that offers 402 horsepower and 369 lb-ft of torque - just amazing specs;
• the engine comes with standard all-wheel drive, it doesn't work as in an SUV but helps to get great traction and handling;
• the powerplant is equipped with the nine-speed automatic transmission - a pretty reliable and non-problematic unit for this car;
• the engine is codenamed M139, it was first released in 2019 and we still don't know enough about its real lifespan;
• this is the mild-hybrid powerplant (E-Turbo series) with an electric motor for more power and better acceleration;
• the engine has the combined (direct plus port) fuel injection system which protects it from carbon buildup on intake valves;
• the rated fuel consumption is 18 MPG in the city and 27 MPG on highways, but this is rather fiction.

Fuel consumption is one of the important things you should understand. If you are going to drive this car like your granny would drive, then, probably, seeing 18 MPG on the trip computer in the city is possible. In normal conditions, you will want to press that gas pedal hard and get the pleasure of driving. Of course, in this case, you will see 10 to 15 MPG, on average.

This engine is quite new and we still don't know a lot of important stats about it. But it has been used in several different AMG models and also in the Lotus Emira which speaks for itself. I hope you understand that when buying the C 43 AMG Mercedes C-Class you are getting one of the best Mercedes engines available on the market now.

How long will this engine last in your C-Class?

Well, Mercedes actually said its word about the durability of this engine claiming that it can go approximately 150,000 miles (they said 250,000 kilometers) without any serious repairs or rebuild. It's not bad for an engine like this one, but how achievable is this?

When you get 200 horsepower from 1 liter, you should be sure that the engine is tough. But I don't see any serious changes in comparison with previous models of high-performance engines in Mercedes-Benz vehicles. So, I am a little less optimistic than the engineers and marketing specialists of Mercedes company.

I believe, hitting an average of 120,000 miles will be just a great result for this engine. The advantage in the situation of the C-Class AMG is that the car itself is small and light. Also, the transmission is good and reliable and it should go at least the same distance without serious problems.

One of the concerns is the battery pack. But this is a mild hybrid vehicle, so the battery isn't huge and it should cost you a fortune if you need to replace it eventually.

What are the common problems with the AMG C 43 engine in the C-Class?

Well, still not so many owners reported problems with these vehicles. I can see that the engine is not bad at all and is worth your attention. But you should also think about possible issues that you can deduct if you know what technologies are used in this engine. I personally see several potential issues that can cause serious or even fatal situations with this engine.

Here are some of them:

1. Camtronic issues

All Mercedes engines with Camtronic start glitching at about 50K miles and if you are lucky enough to have it repaired under warranty, you will save hundreds or even thousands of dollars. Camtronic on exhaust valves is pretty faulty and will need much more attention here than in other, less powerful, engines.

Unfortunately, all valve timing technologies that Mercedes now uses in its cars are not perfect. They fail quite early and you will lose the power which will mean the AMG advantage of your expensive C-Class sedan will vanish. Of course, you will have to repair it.

2. Quite complicated engineering

All AMG engines are engineered in such a way that only the Mercedes dealership can repair them. I understand that this is not just the business but also the necessity to include new technologies to achieve so cool results from just 2 liters of displacement. So, the Mercedes C-Class AMG C 43 will cost you quite a lot in maintenance and repair. If you don't know about the prices in Mercedes dealerships, you should check them before you buy this vehicle.

3. Fuel injection problems

The weakest part of the system is the high-pressure fuel pump. But the fuel injectors can also be faulty. The pump will cost you a fortune. Each injector will also be surprisingly expensive. Again, I don't know if some random repair shop will agree to replace one of the injectors or the HPFP in this car. So, the overall repair costs will be huge even if the car will only need fuel injector cleaning or replacement.

4. Bad maintenance problems

I've seen several forum threads where owners complained about severe problems with the turbo, valve timing, and even the engine head. These engines require only Mercedes OEM oil and filters. If you install or use something different, there is a high chance that the engine will fail within 10-15 thousand miles.

The oil should be of a certain viscosity and have a certain range of additives to clean the engine, lubricate it, and not burn in large quantities. If you want to drive the C-Class AMG for a long time, you should obviously spend some money on maintenance and not forget about the regular oil change.

How can you prolong the life of this engine?

I'm pretty sure that if you just drive the AMG C 43 vehicle like your everyday car without pressing the pedal to the metal, you can take it to 200,000 miles without rebuilding the engine or replacing it. But if I imagine an average AMG vehicle buyer, my dreams of about 200K miles immediately vanish.

But how can you make sure that your engine is going to live long? Here are some tips:

• warm the M139 engine up before you hit the gas pedal - it should be completely warmed up for such a driving style;
• maintenance is the religion for this engine, you shouldn't miss the schedule or try to buy some aftermarket oil or filters;
• keep an eye on fluid levels - coolant and oil should be checked because the engine may suddenly start burning them in high revs;
• avoid overheating - even though the engine can withstand high temperatures, this doesn't prolong its life.

I can't say that driving this engine carefully will prolong its life. Yes, it will, but who cares? You will still drive it like an AMG car, so I won't waste your time saying those obvious things.

I would only use premium fuel in this engine because it adds up several horsepowers and helps you avoid detonation inside the engine. Also, it will most likely save the cat converter from burning prematurely.

Overall, the M139 engine by Mercedes-Benz doesn't seem revolutionary new in terms of technology and I can predict it will live about 120K miles till it asks for some serious and very expensive repairs. But if you are looking for a small performance sedan with a lot of comfort and the possibility to use it as a daily driver, maybe, the C-Class AMG C 43 is one of the best options.