The first diesel Mercedes with the injection system like Common Rail was introduced at the end of 1997. It was Motor 2.1 CDI with the designation of OM 611 with a capacity from 82 to 204 hp. He began the beginning of a new family of engines used, including in commercial vehicles and light trucks (OM 646 and OM 651).

Depending on the purpose, diesel received a different commercial designation. For example, 180 CDI, 200 CDI, 220 CDI and 250 CDI. There are also modifications of Bluetec and BlueEfficiency.

Initially, this engine had a working volume of 2151 cubic meters. cm and power 102 or 125 hp In the design of the unit, the Bosch injection system with the first generation Common Rail Rail electromagnetic nozzles, the exhaust gas recirculation system and turbocharging system were used. Drive Timing Type, which reduces maintenance costs.

In 1999, versions of 115 and 143 hp appeared, and three years later - a new generation 2.1 CDI with the designation of OM 646 and return 122 and 150 hp Later, the remaining modifications were also presented. Engine received cOMMON system New generation Rail, EGR electric valve and generator with liquid cooling. OM 646 was additionally equipped with balancing shafts and electric pump (instead of mechanical).

The last generation of Motors 2.1 CDI was called Ω 651 and debuted in 2008. This is almost another engine, in which the diameter of the cylinder is changed (reduced to 83 mm) and the piston stroke (increased to 99 mm). Working volume new version The unit has decreased to 2143 cm3. The compression ratio was reduced to 16.2: 1. The engine block, as before, is made of cast iron, and the head is made of light alloys.

The new turbodiesel is very advanced, which means more expensive in maintenance and repair. It has two turbocharger (in versions of more than 143 hp), which create pressure of 2 bar. Single-row timing chain is behind the engine - from the side of the box. Balancing shaft is driven by gear gears.

In more powerful modifications, Delphi piezoelectric nozzles are applied. Injection pressure reaches 2000 bar. For comparison, injection pressure 611 - 1350 bar. Common Rail injection system provides soft engine operation and low fuel consumption. Economicity, of course, depends on the degree of forcing and the weight of the car. In case of MERCEDES C-CLASS The average consumption of the 143-strong version is about 7 l / 100 km. Contrary to generally accepted opinion, the injection system is not problematic and too expensive in repair.

Mechanics emphasize that secondary market Most diesel Mercedes have a much greater mileage than counters show. From here and the troubles facing the second and subsequent owners. The turbocharger and two-mask flywheel are rarely summarized 150,000 km.

The problems appeared in the last motors of OM 651. They are associated with Delphi fuel injectors (defective already replaced) and refrigeration leaks. The costs of replacing the nozzles were partially compensated by the manufacturer of nozzles.

General Engine Faults 2.1CDI

Most often, the Mercedes owners with a large mileage and engine 2.1 CDI have problems with the morning launch and power drop. In both cases, there are several reasons. Problems with the launch, as a rule, are associated with a drop in pressure in the injection system due to a malfunction of the pump, nozzles or valve high pressure. Power drop can be caused by a malfunction of the flaps in the intake manifold.

In vehicles equipped with solid particle filter (not used at all, in 2003 it appeared in some models, and later began to be applied massively) and moves only around the city, problems with self-degeneration arise, as well as oil discharge fuel.

Problems were aggravated after the engine appearance of the EM series 651. The nozzles were out of order of 50,000 km. Some sources report that the defect touched about 300,000 cars.

Pulley generator

The pulley of the generator has a free move clutch, which often fails. The malfunction is accompanied by noise, and the replacement with replacement can accelerate the belt tensioner wear. Elimination of the problem is not complicated and not too expensive. The pulley costs less than 60 dollars.

Electromagnetic valve

Electromagnetic valves are used to control the performance of the turbocharger and EGR (old engines 2.1). When they refuse, there is a drop in power. Repair is fast and inexpensive - about 50 dollars.

Injectors

Symptoms: Problems with engine start, uneven operation, excessively high fuel consumption. Nozzles can be repaired. The cost of the service is about $ 70 per piece.

More serious troubles occur when they lose the tightness of sealing washers under nozzles. Removing nozzles is a difficult task. They can accumulate - it will take the milling.

Thermostat

Symptoms: Too slow engine heating. The thermostat can open at a temperature of 45 degrees. Attention! By acquiring this detailAlways use a catalog number - the thermostat has been repeatedly modernized. The cost of the new is about 60-70 dollars.

Om 651 engine malfunctions

Injectors

Shortly after the start of production of the new 2,1-liter turbodiesel, it turned out that Delphi piezoelectric nozzles are made with a defect. Replacement is needed.

Cooling fluid leaks

Unifunral antifreeze leaks can soon lead to overheating of the engine. The cooling system pump is to blame. A miserable pump must be replaced.

Inlet collector flaps

The dampers are wearing and destroyed over time. This leads to a noticeable drop in power, and in the event of a break - to damage the engine. Due to the lack of details, it is necessary to change the entire collector, which increases the cost of repair up to 600 dollars.

IN Russian conditions Operating ("Divine" of poor quality) fuel filter It is recommended to change every 40,000 km (according to the prescriptions of the manufacturer - 60-80 thousand km). This will extend the service life of the injection system.

Burning the particulate filter

The samoregeration process is not possible during the operation of the car mainly at short distances. Periodic creation of favorable conditions is necessary - long-lasting highway trips.

GRM drive

In the engines, the timing chain drive is used that does not require maintenance. The chain, as a rule, does not require replacement. However, at large runs, it is recommended to check its condition.

Service

* All cars with CDI have on-board computerdetermining the oil replacement period;

** The manufacturer does not require periodic replacement of DPF;

*** No less often than every 250 thousand. km or every 15 years.

Conclusion

Engine 2.1 CDI is not as reliable as old motors, but in return, it gives a higher return, low fuel consumption and soft work. As a rule, only mounted and auxiliary equipment fail. The service life of the crystal-connecting mechanism is very significant.

Technical data MERCEDES 2.1 CDI - Part 1

Technical data MERCEDES 2.1 CDI - part 2

Application

MERCEDES C-CLASS

Mercedes E.

Mercedes S.

Mercedes SLK.

Mercedes ML.

Mercedes Vito, Viano, Sprinter

Mercedes GLK.

Almost everyone carburetor engines Quadrocycles and motorcycles are traditionally equipped with CDI ignition (Capacitor Discharge Ignition). In this system, the energy accumulates in the condenser and at the right moment it is discharged through the primary winding of the ignition coil, which is a raising transformer. The secondary winding is a high voltage, which breaks the gap between the candle electrodes forming an electric arc that flames the mixture of gasoline and air.

To synchronize the ignition operation, the induction sensor of the crankshaft position - DPK, which represents a coil, wound on a permanent magnet core:

The label serves the tide on the iron case of the generator rotor (in the people they are called the flywheel):

When the tide rushes past the core of the sensor, it changes the magnetic flow through the coil, thereby inducing the voltage at the outputs of this coil. The form of the signal is obtained:

Those. Two impulses of different polarity. Almost all engines the polarity of the sensor inclusion is such that the first one follows a positive impetus corresponding to the beginning of the tide, and the second is negative - the end of the tide. For normal operation of the engine, the ignition should occur a little earlier than the upper dead point - the NTC, so that the maximum pressure of the combustion products reached the VMT. It is "a little earlier", it is customary called the ignition ahead of the ignition - and to measure in degrees, which remained to touch the crankshaft to NTC. When starting the engine, the Woz should be minimal, and with an increase in revolutions it should increase. As mentioned above, the DPK issues two synchronization pulses - the beginning of the tide and the end of the tide. In simple (non-microprocessor) CDI systems, the end of the tide corresponds to the pre-installed uz - on this signal, there is ignition when the engine starts and on idling. The beginning of the tide corresponds to the uzew on high revs. Most often in such systems, the end of the tide is set to 10-15 degrees of ahead, and the "long" tide from 20 to 30 degrees. At the same time, the advanced CDI blocks smoothly change the moment of sparking from the "end of the tide" to the "beginning of the tide" in the interval from 2000 RPM to 4000 RPM, and cheap with an increase in revolutions simply jump at the beginning of the tide. In the microprocessor CDI systems, the length of the tide is much more - from 40 to 70 degrees, and the end of it as before it corresponds to the pre-installed uz, and the beginning is the point of reference for the microprocessor, which, depending on the revolutions, exhibits the desired Woz.
IN different engines The "length" of the tide is different, so the CDI blocks even with the same connectors most often not interchangeable!
It is worth it to add that for the power of the CDI blocks, high voltage is necessary, since The time of energy accumulation in the condenser is limited to its tank is taken small but it is charged with high voltage - several hundred volts. For this B. simple systems The generator has an additional high-voltage winding. The power of this winding is small, so the spark in such systems at the start of the engine is weak, which makes it difficult for winter operation. To avoid this problem, the so-called DC-CDI is used, the capacitor is charged from the raising voltage converter feed from the battery. In such systems, the power of the spark does not depend on the revolutions and the start of the engine in the cold time is much easier.

Now about the flaws of the ignition CDI. The most important disadvantage that is impossible to eliminate for little money is a very "weak" "short" spark. It is impossible to build a powerful CDI system without significant material costs.
For example CDI for car engines Patriotic development cost more than a thousand dollars, and imported, which are installed on racing cars with high-breasted motors can cost more than one thousand.
The larger the volume of the cylinder in the engine, the stronger the lack of energy sparks affects. It is expressed in incomplete combustion of fuel, power loss, very big flow Fuel. When CDI only appeared to put it on mopeds, motorcycles, most often the engine volume was 50 cubes. Such a small amount of fuel and air mixture easily managed to burn from the weak spark of CDI. With an increase in the cube, it became clear that something should be changed and DC-CDI appeared. But the cube continued to grow and along with it and the number of gasoline, which carries out literally into the pipe. Even invented systems that survive gasoline in exhaust pipe! : O) I do not understand what the manufacturers of motorcycles thought all this time, because at the same time the other ignition system was used for cars, with the accumulation of energy in the inductance coil, which allowed for the same money to get the power sparks hundreds of times more And solve all problems with ignition. Of course, now on injector engines Modern motorcycles no longer put CDI. But it's a drop in the sea! To date, the picture is such that 90 percent of motorcycles and quad bikes continues to eat gasoline and spin it into the atmosphere.
It would seem that everything would be very simple - it is necessary to change on all the ignition for more perfect, but there are a few but! If this CDI is very expensive. If this IDI is both in injection systems, then for its work it is necessary to change the generator rotor, which is still more expensive. (For correct management of the modes of operation of the coil in the IDI system, there is not a single mark on the flywheel, several dozen short marks are used - essentially a gear wheel with synchronization over the missed tooth) all this is so if you solve the task in the forehead. But if you think a little bit, apply a powerful microprocessor and show ingenuity, it turns out that not everything is so bad!

For the first time, the design of the engine operating on the basis of the principle of self-ignition fuel under the action of heated during compression of air was patented by Rudolph Diesel in 1892. Debut engines were adapted to work on vegetable oils and light oil products, and in 1898 they could already work on crude oil. Manufacturers passenger cars Dided the diesel engines only in the 70s of the 20th century, when prices for fuel increased significantly.

Advantages of diesel engine

Since those times, diesel engines have been significantly improved and successfully used in various equipment cars. Many motorists prefer "Diesels" ordinary gasoline enginesbecause the first is more economical (consumption up to 30% less fuel, which is at times cheaper different species gasoline) and have a higher torque. And it even despite the fact that cars equipped with "diesel engines" have a much greater cost. Yes, and the engines themselves have increased weight and size due to the fact that they are intended to withstand colossal loads.

Characteristics of diesel engines TDI and CDI

To date, there is a mass of types of diesel engines. However, if you intend to choose between such aggregates, like TDI and CDI, you should compare their characteristics in advance to take the right decision and get in the end exactly what you need.

TDI engine (Turbocharged Direct Injection) was developed by the German company Volkswagen. His main distinctive feature, in addition to direct injection, is the presence of a turbocharger with a variable turbine geometry. The system as a whole guarantees optimized filling of cylinders, highly efficient fuel combustion, efficiency and environmental safety. The TDI-motor turbocaddv coordinates the energy of the exhaust gas flow and thereby ensures the necessary air pressure in the extensive range of the engine rotation frequency.

Such motors are considered sufficiently reliable and unassuming to use. At the same time, they possess one unpleasant feature. The fact is that TDI turbine high temperatures Operation (and it has a stream of exhaust gases up to 1000 ° C) and an impressive frequency of rotation (approximately 200 thousand revolutions per minute) has a small resource, only about 150 thousand km of car run. But the engine itself can withstand to 1 million km.

Diesel CDI (Common Rail Diesel Injection) is the result of the Mercedes-Benz concern. In it, the innovative injection system COMMON RAIL was applied. It made it possible to significantly reduce fuel consumption, and the power was increased almost 40%. It is worth noting that CDI motors require considerable costs. serviceHowever, when the low wear is achieved, repairs are needed much less frequently. It would seem that the system is perfect, but this engine can be sensitive to poor-quality fuels.

However, modern diesel engines actually do not differ much, with the exception of some minor moments. So unambiguously answer the question of what kind of engine is better, it is impossible. It is necessary to be guided by its own needs, tastes and preferences. But the choice itself diesel engine - This is definitely the right decision.

The HDI abbreviation is assigned to engines that are based on technology COMMON RAIL. (Developed by Bosch in 1993). The same motor and HDI technology has developed world famous automotive concern PSA Peugeot Citroen. HDI, as I said, belongs to the line of engines with direct injection, characteristic differences. Reduced fuel consumption by ~ 15%, decrease noise by ~ 10DB, while improving the power by as much as ~ 40%. Motors with HDI prefix are considered more endless and "live".

Engine TDI

The reduction of TDI is perhaps the most popular and easily deciphered. The first letter "T" in this abbreviation indicates the presence of turbocharging, which allows you to get a serious increase in power. It has all the properties inherent turbocharged engines, it is more economical, has a cleaner exhaust, while more expensive in service. In addition, few people know that most turbines installed on the turbo engine are calculated by ~ 150-200 thousand km. Run, and this is despite the fact that the motor itself is usually "millionth".

Engine SDI

SDI class motors are distinguished by the duration of "life" and the simplicity of design. Large runs For SDI is not a problem, the motors are very hardy and reliable, but if the repair is still required, then it is unlikely to please you.

Engine CDI

Motor with a CDI signboard - development "Mercedes", which is based on the same Common Rail technology as the above power units. The CDI line motors are more demanding on fuel quality (often "composting brains" fuel, nozzles, etc.), while they are very economical and dynamic on the road.

Well, that's all. I hope intelligibly explained what the difference between HDI, TDI, SDI, and CDINow you can easily navigate and choose for yourself the engine suitable and class. Thank you for your attention to new meetings.

High! We have already described how to install electronic ignition on a motorcycle with your own hands in one of the previous publications. Nevertheless, a separate article would like to devote the principle of operation of the CDI system, describe the reviews about it, as well as the features of practical application. Buy this element of electronics recently want more and more people.

What is condenser ignition?

Expanding the above abbreviation "Capacitor Discharge Ignition") of the "Capacitor Discharge Ignition") is described in the "ignition of the condenser" (namely, the "Capacitor Discharge Ignition" abbreviation is translated). Sometimes the latter is called "thyristor ignition", since the switching functions in it performs the item called a thyristor.

In the principle of operation of this unusual, retro-technician admirers are laid for the use of a condenser discharge. A counterweight contact system, CDI (reviews about which predominantly positive) does not use the principle of the ignition interrupt. Nevertheless, and contact electronics Has a condenser, the main mission of which was to eliminate interference and a decrease in the level of intensity of sparking on contacts.

Separate nodes "Capacitor Discharge ignition" are designed to directly accumulate electricity. There were such details for almost half a century ago. From the 70s. Last century, powerful capacitors began complementing rotary-piston-type engines used mainly in the creation vehicle. In many ways, this type of ignition is similar to systems, which accumulate electricity. Nevertheless, the difference in them is also noticeable.

How does CDI work?

The above-mentioned element of the electronics of the motor - use direct currentwhich is not capable of passing through the primary winding on the coil. It contains the last in the already charged condenser connected to the coil. The voltage in such an electronic circuit, in most cases, is pretty serious, reaching a few hundred volts.

Among the obligatory elements of ignition, the discharge of a motorcycle and auto motor condenser can be seen the voltage converter (the main mission of which is the charge of the capacitors of the accumulative type), the cumulative capacitor itself, the coil and electro-key itself. The latter can be represented as thyristors and transistors.

Spark out the discharge of the condenser

The above Capacitor Discharge Ignition system, which can be purchased in many corners of the post-Soviet space, has several minuses. So, in the construction part, the creators are pretty complicated. In addition, the lack of duration of the pulse level is another disadvantage of "CDI". However, as the advantages of the condenser ignition, it is possible to highlight the presence of a steep edge of the high-voltage pulse. This moment is very important when using such electronics in soviet motorcycles, the candles of which are very often flooded with excessive amount of fuel due to the presence of poorly designed carburetors.

Thyristor ignition is functioning without the use of additional sources of current generation. The latter (in the form of AKB) are needed only to launch the electric starter or a motorcycle plant with a foot (kick-started), for example.

Discussing the prevalence electronic ignition From the charge of the capacitor, it should be noted its active use on foreign chainsaws, scooters and motorcycles. For the Soviet motor industry, its use was low-key. But in some of our cars, such as (gas and zil) electronic system The ignition of the CDI was installed often. Reviews about her successful operation clearly contribute to this.