M274 engine: Technical characteristics, maintenance, problems, Chip Tuning

Mercedes Benz model M274 is an in-line 4-cylinder engine operating on the principle of internal combustion. It is equipped with a turbocharger, as well as direct fuel injection developed by Mercedes Benz. The unit is a logical continuation of the early M270 series, which differs in the form of a longitudinal installation directly under the hood of the car. All problems of the M274 engine come, by and large, from violations committed during operation.

Short story

Towards the end of 2011, a company with a representative office in Stuttgart produced the next version of the four-cylinder engine, labeled M274 DE 20; it became a worthy replacement for the M271 EVO turbocharged unit, having received a number of qualitative differences. The new engine model has become lighter than its predecessors and has a reduced coefficient of friction; it uses an open-type cylinder block made of aluminum and equipped with cast iron liners.

The M274 model from Mercedes Benz received its official presentation only in the first half of 2012. Then, in 2013, the next modification was introduced, focused on working with natural gas; it was given the code name NGT. In addition to Mercedes-Benz models, this engine was used for the Infiniti Q50.

Detailing

If we consider the technological characteristics of the Mercedes M274, we can note that its design and main elements are similar to the early version of the M270. A distinctive feature is the successful combination of BlueDirect technology with Camtronic systems, as well as start-stop. In total, two working versions of the engine were created, one of them was designated DE16 AL, and the other was DE 20 AL.

The presented unit is equipped with balancer shafts, new oil and water pumps with variable pumping rates. The resulting improvements made it possible to significantly reduce the friction torque, facilitating the interaction of the leading parts inside the motor. The crankcase block, made of an alloy with aluminum, has noticeably lost weight. Thanks to special nozzles, fuel atomization began to be carried out in a special way, which reduced the time required for combustion and increased the efficiency of the process.

For the same purpose, the developers used multi-spark ignition, capable of activating four discharges within one millisecond. Changing the operating modes of the camshafts gives the unit the opportunity to be in optimal mode at any change in speed.

What problems are inherent in the M272 engine?

The M272 is made of gross design miscalculations, since it could not even travel 100,000 km without problems. Often, engine operation is accompanied by ringing and clanging of the chain, which indicates a stretched chain and a failed balancer shaft sprocket.

The consequence of such malfunctions is uneven engine operation with dips, loss of power and increased fuel consumption.

Balancer shaft gear

The balancer gear problem is the main one in this motor. The licking of the teeth on the gear occurs at 80,000-100,000 km.

The cause of the problem is an engineering miscalculation when selecting the material from which the star was cast. In specialized service stations, the defect can be determined using a motoscope through the oil filler neck. Wear on the star indicates the need for urgent engine repair.

Malfunctions caused by a licked balancer shaft star:

• Engine operation is accompanied by a rustling or clanging sound.
• On the camshafts of the right cylinder head, the phases are shifted, and this leads to an increase in the temperature in the cylinder, which results in overheating of the catalyst, its destruction and the formation of scuffing by pieces of ceramic.
• Mismatch of timing marks, leading to increased fuel consumption and deterioration of dynamic characteristics.
• The oil pump becomes clogged with metal shavings, the pressure of the oil system decreases, leading to partial oil starvation.
• There is a high probability of chain jumping, leading to bending of the valves.

If the gear malfunctions, the following manipulations must be carried out:

• remove the engine
• replace the balancer shaft with star,
• clean the oil pump, in the worst case, replace it,
• electromagnetic camshaft position sensors - for replacement,
• changing the oil with filter, with advance flushing of the oil system.

Intake manifold

The complex design of the intake manifold flaps leads to regular breakage of plastic rods, which clearly cannot withstand thermal stress. Rods also break due to the build-up of oil deposits and natural aging.

There are special repair kits for rods, but it is recommended to replace the manifold assembly. The actual service life of the dampers is 70,000 km. Even if one damper does not work, the entire assembly will have to be replaced.

Detonation

The engine operates in critical temperature conditions. The operating temperature here is 100 degrees. By 150,000 km you have to change the valve stem seals, as they completely dry out by such a mileage.

The high engine temperature is determined by the operation of the cooling fans. On the M112, a reliable viscous coupling was used. Here the fans are intelligently controlled, so they can only start working at 105 degrees.

Elevated temperatures promote detonation, which is extremely detrimental to the aluminum block and lightweight pistons.

Seizure of cylinder walls

Aluminum liners coated with Silitec are extremely vulnerable to the quality of fuel and oil. By 200,000 km, if not earlier, the liners become covered with abundant scoring. Among other things, catalyst resolution is also involved in the formation of scoring and pitting.

The consequence of scuffing is increased oil consumption with all that follows in the form of loss of traction and increased fuel consumption and difficult engine starting.

Equipment

In the updated Mercedes Benz M274 engine, the distance between the cylinders was 90 mm, while the cylinder diameter was 83 mm, which made it possible to rationally distribute the loads. The interior of the block also underwent changes; the design used:

• a hollow model of the crankshaft, whose stroke was 92 mm and it acquired equipment of four counterweights;
• improved piston design;
• new connecting rods.

The aluminum block, equipped with cast iron cylinders, is covered here with a two-shaft head structure, provided with a structure of 16 valves. Additionally, the unit is equipped with piezo injectors using direct fuel injection. The diameter of the installed intake valves is 31.5 millimeters, while the exhaust valves are 25 mm, while the thickness of each valve stem is 6 mm.

A special effect was achieved using a system that changes phases for gas distribution, which was installed on the intake and exhaust shafts. A high-strength chain was used to drive the timing chain, which is designed for approximately 100,000 kilometers. Plus, the M274 engines are equipped with a turbine called IHI AL0071.

Excerpt characterizing the Mercedes-Benz M270 (engine)

“I don’t take back my word on anything,” he said. - And then, Sonya is such a charm that what fool would refuse his happiness? “No, no,” Natasha screamed. “We’ve already talked about this with her.” We knew you would say this. But this is impossible, because, you know, if you say that - you consider yourself bound by the word, then it turns out that she seemed to say it on purpose. It turns out that you are still forcibly marrying her, and it turns out completely different. Rostov saw that all this was well thought out by them. Sonya amazed him with her beauty yesterday too. Today, having caught a glimpse of her, she seemed even better to him. She was a lovely 16-year-old girl, obviously loving him passionately (he did not doubt this for a minute). Why shouldn’t he love her now, and not even marry her, Rostov thought, but now there are so many other joys and activities! “Yes, they came up with this perfectly,” he thought, “we must remain free.” “Well, great,” he said, “we’ll talk later.” Oh, how glad I am for you! - he added. - Well, why didn’t you cheat on Boris? - asked the brother. - This is nonsense! – Natasha shouted laughing. “I don’t think about him or anyone else and I don’t want to know.” - That's how it is! So what are you doing? - I? – Natasha asked again, and a happy smile lit up her face. – Have you seen Duport? - No. – Have you seen the famous Duport the dancer? Well, you won't understand. That's what I am. – Natasha took her skirt, rounding her arms, as they dance, ran a few steps, turned over, made an entreche, kicked her leg against the leg and, standing on the very tips of her socks, walked a few steps. - Am I standing? after all, she said; but couldn’t help herself on her tiptoes. - So that’s what I am! I will never marry anyone, but will become a dancer. But do not tell anyone. Rostov laughed so loudly and cheerfully that Denisov from his room became envious, and Natasha could not resist laughing with him. - No, it’s good, isn’t it? – she kept saying. - Okay, don’t you want to marry Boris anymore? Natasha flushed. - I don’t want to marry anyone. I'll tell him the same thing when I see him. - That's how it is! - said Rostov. “Well, yes, it’s all nothing,” Natasha continued to chatter. – Why is Denisov good? – she asked. - Good. - Well, goodbye, get dressed. Is he scary, Denisov? - Why is it scary? – asked Nicholas. - No. Vaska is nice. - You call him Vaska - strange. And that he is very good? - Very good. - Well, come quickly and drink tea. Together. And Natasha stood on tiptoe and walked out of the room the way dancers do, but smiling the way only happy 15-year-old girls smile. Having met Sonya in the living room, Rostov blushed. He didn't know how to deal with her. Yesterday they kissed in the first minute of the joy of their date, but today they felt that it was impossible to do this; he felt that everyone, his mother and sisters, looked at him questioningly and expected from him how he would behave with her. He kissed her hand and called her you - Sonya. But their eyes, having met, said “you” to each other and kissed tenderly. With her gaze she asked him for forgiveness for the fact that at Natasha’s embassy she dared to remind him of his promise and thanked him for his love. With his gaze he thanked her for the offer of freedom and said that one way or another, he would never stop loving her, because it was impossible not to love her. “How strange it is,” said Vera, choosing a general moment of silence, “that Sonya and Nikolenka now met like strangers.” – Vera’s remark was fair, like all her comments; but like most of her remarks, everyone felt awkward, and not only Sonya, Nikolai and Natasha, but also the old countess, who was afraid of this son’s love for Sonya, which could deprive him of a brilliant party, also blushed like a girl. Denisov, to Rostov’s surprise, in a new uniform, pomaded and perfumed, appeared in the living room as dandy as he was in battle, and as amiable with ladies and gentlemen as Rostov had never expected to see him. Returning to Moscow from the army, Nikolai Rostov was accepted by his family as the best son, hero and beloved Nikolushka; relatives - as a sweet, pleasant and respectful young man; acquaintances - like a handsome hussar lieutenant, a deft dancer and one of the best grooms in Moscow. The Rostovs knew all of Moscow; this year the old count had enough money, because all his estates had been remortgaged, and therefore Nikolushka, having got his own trotter and the most fashionable leggings, special ones that no one else in Moscow had, and boots, the most fashionable, with the most pointed socks and little silver spurs, had a lot of fun. Rostov, returning home, experienced a pleasant feeling after some period of time trying on himself to the old living conditions. It seemed to him that he had matured and grown very much. Despair for failing to pass an exam according to the law of God, borrowing money from Gavrila for a cab driver, secret kisses with Sonya, he remembered all this as childishness, from which he was now immeasurably far away. Now he is a hussar lieutenant in a silver mentic, with a soldier's George, preparing his trotter to run, together with famous hunters, elderly, respectable. He knows a lady on the boulevard whom he goes to see in the evening. He conducted a mazurka at the Arkharovs’ ball, talked about the war with Field Marshal Kamensky, visited an English club, and was on friendly terms with a forty-year-old colonel whom Denisov introduced him to. His passion for the sovereign weakened somewhat in Moscow, since during this time he did not see him. But he often talked about the sovereign, about his love for him, making it felt that he was not telling everything yet, that there was something else in his feelings for the sovereign that could not be understood by everyone; and with all my heart he shared the general feeling of adoration in Moscow at that time for Emperor Alexander Pavlovich, who in Moscow at that time was given the name of an angel in the flesh. During this short stay of Rostov in Moscow, before leaving for the army, he did not become close, but on the contrary, broke up with Sonya. She was very pretty, sweet, and obviously passionately in love with him; but he was in that time of youth when there seems to be so much to do that there is no time to do it, and the young man is afraid to get involved - he values ​​​​his freedom, which he needs for many other things. When he thought about Sonya during this new stay in Moscow, he said to himself: Eh! there will be many more, many more of these, somewhere, still unknown to me. I’ll still have time to make love when I want, but now there’s no time. In addition, it seemed to him that there was something humiliating for his courage in female society. He went to balls and sororities, pretending that he was doing it against his will. Running, an English club, carousing with Denisov, a trip there - that was another matter: it was befitting of a fine hussar.

Specifications

Cars equipped with a power unit with the designation M274 from Mercedes Benz meet the requirements of the Euro-6 class standard. The engine data was presented in two main versions, namely DE16 AL plus DE 20 AL.

DE16 AL

This interpretation is presented in the form of a motor with a volume of 1595 cm3. Its rated power can vary in various models from a value of 95 kW, a rotation speed of 1200 - 4000 rpm and a torque force (hereinafter referred to simply as Torque) of 210 Nm, to a value of 115 kW, a speed of 5000 rpm and a torque force of 250 Nm.

DE 20 AL

This interpretation is presented in the form of a motor with a volume of 1991 cm3. Its rated power can vary in different models from a value of 135 kW, a frequency of 5000 rpm and a torque force (hereinafter referred to simply as Torque) of 270 Nm, to a value of 180 kW, a frequency of 5500 rpm and a torque force of 370 Nm .

Disadvantages and characteristic malfunctions

To improve the performance parameters of the M274 engine, Mercedes Benz experts recommend using oil only from trusted manufacturers and replacing it twice as often as scheduled. In addition, monitor compliance with the scheduled engine maintenance regulations, as well as warm up the unit when operating in winter. In many ways, the condition of the engine depends on how smoothly its operation is carried out. Malfunctions that occur can be identified by the following series of symptoms.

1. The occurrence of noise or crackling noise during a cold start, in the period after passing the 100,000th mark, indicates probable wear in the phase shifter design. Until November 2011, the engine used the version A2700500847, which is extremely unreliable. After the specified time, version A2700501147 was used, the characteristics of which were noticeably improved.
2. Temperature disturbances caused by excessive engine overheating are associated with various types of contaminants. To avoid such consequences, it is necessary to periodically check the pump, as well as the thermostat, which are the most likely root cause. Less commonly, the problem may lie in a blockage in the radiator system, which is also recommended to be cleaned periodically.
3. If a characteristic whistle occurs, you should check the alternator belt, which most likely needs to be replaced.

It is important to remember that the service life of the turbine ranges from 100 to 150 thousand kilometers, after which care should be taken to replace it.

Destruction of the surface of the cylinder walls

Here we come to another very common problem with Mercedes V6 (M272) and V8 (M273) engines. The detonation already mentioned above leads to destruction of the surface of the cylinder walls. Scouring on the surface of the cylinders in V6 (M272) and V8 (M273) engines also occurs due to clogged or destroyed catalysts (by the way, both problems arise due to refueling with low-quality fuel or using the wrong engine oil).

The catalyst, when clogged, disrupts the normal operation of the exhaust system. As a result, normal purging of the entire exhaust stops, overheating of the combustion chamber occurs and associated destruction of engine parts. If the catalyst begins to deteriorate, then particles of its ceramic lattice penetrate into the cylinders, where they settle on the cylinder walls and are “pressed” by the pistons - scoring marks appear on the cylinder surface.

Scuffing leads to oil burn, which can be diagnosed both by a rapid decrease in its level and by the bluish tint of the exhaust smoke. Next, the gap between the pistons and the cylinder walls increases, which is already diagnosed by engine knocking : the pistons begin to knock on the cylinder walls when moving at top dead center.