CRDI abbreviation ( Common rail Direct Injection, from the English. direct fuel injection system) is found on vehicles with a diesel engine. This designation was given to the power units that the South Korean auto giant Hyundai / KIA installs on its models.
In other words, Hyundai's CRDI engine is a Korean design and is found exclusively on Korean cars. As for other manufacturers, global companies are also actively using constructively similar analogs. In this article, we will consider a CRDI engine, what it is, what the specified unit has analogues, and also talk about the advantages and disadvantages of this type.
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CRDI diesel engines: pros and cons
As mentioned above, the CRDI designation is used for Korean direct injection (crdi 16v engine, etc.). Other manufacturers also have similar units in their diesel engine lineup.
As an example, we should mention the products of the German brand Mercedes, which received the designation CDI or CRD, the Italian Fiat designated its engines as CDTi. On Ford models, this engine is called TDCi, GM corporation uses the designation CDTi or VCDi, Volkswagen used the TDI designation well known to domestic consumers, etc.
If you do not take into account the differences in the name and some individual design features, all such designations should be understood diesel engine which is equipped with a Common Rail system (direct fuel injection).
Advantages of CRDi motors
The specified type of internal combustion engine (CRDi, CDI, TDI, etc.) allows to achieve significantly lower consumption, as well as reduce the level of harmful substances in the composition of exhaust gases.
The main feature of diesel engines with Common Rail is that fuel is supplied to the injection injectors from a common accumulator, in which the fuel is under high pressure. The design compares favorably with the usual diesel engines with a cam drive and restrictions on the pressure of the supplied fuel.
The general scheme of the system's operation looks like that after turning the ignition key, diesel fuel is pumped by a separate pump into the Common-rail fuel rail (from the English common, single rail, line). This rail is the "battery" mentioned above. Inside the common rail, the fuel is constantly under high pressure for injection. Next, the diesel fuel comes from the rail through the fuel lines to the injection nozzles under pressure.
This solution has a number of obvious advantages over other diesel engine power systems. First of all, fuel efficiency is significantly improved.
The point is that maintaining a constant high pressure allows you to effectively atomize fuel directly into the combustion chamber (direct injection). The higher the pressure, the better the diesel fuel is dosed and sprayed, as a result of which the subsequent combustion of the charge occurs fully and with maximum energy output to the piston.
The most complete combustion of the fuel-air mixture is a guarantee that the content of toxic substances in the exhaust gases will be minimal, while the engine power is noticeably increased.
- The main feature of this power system is that the fuel pressure is constantly kept at the same level, that is, it does not depend in any way on the crankshaft speed, fuel volume and other factors that can affect the injection in relation to different operating modes of the internal combustion engine.
The fuel delivery is realized in such a way that the fuel injectors are opened for injection under the control of a separate EDC control unit. This became possible due to the fact that special electromagnetic solenoids are structurally incorporated into the injectors of the fuel supply system.
This is a fundamental difference between the Common Rail system and engines with a cam injection pump, the solution allows the lifting of the needle in the injector nozzle using a controlled solenoid, and not as a result of fuel pressure.
- In the Common Rail system, the total amount of fuel for injection, the injection advance angle and injection pressure are determined by software, that is, it is sewn into and applied in relation to different modes and conditions of engine operation.
In other words, fuel injection and injection are completely separate processes. This results in another significant advantage, which allows injection to be multi-phase (at least two-phase). In parallel with this, the injection pressure can also be dynamically changed taking into account speed mode, speed and load on the internal combustion engine.
- Moreover, Common Rail also allows phased injection in one stroke. We add that the early development of this system assumed only double injection. The main challenge early on was the need to get rid of.
Today, modern power systems can provide about 9 fuel injection phases. Phased injection has added to the list of advantages already described above a noticeable reduction in the noise level during the operation of the diesel engine.
- We also note that the constant high fuel pressure in the rail made it possible to accurately dose the fuel during the entire injection time (the duration of the injector opening). At the same time, in designs with a conventional injection pump, this possibility was completely absent.
The fact is that attempts at any pressure changes led to the fact that wave-like pulsation (wave hydraulic pressure) naturally occurred in the pipelines from the pump to the nozzles.
As a result of these pressure waves, fuel lines are quickly damaged. By this the reason for the injection pump have a strict limitation in terms of the pressure at which they pump fuel to be supplied to the injectors.
In view of the above, it becomes clear why conventional injection pumps do not develop pressures of more than 300 kg / cm2, while Common Rail systems significantly exceed this mark. For example, CRDi assumes pressure up to 2000 bar without pressure fluctuations and destruction of system elements.
Disadvantages of the CRDi engine
As for the disadvantages, CRDi units and other installations equipped with Common Rail have a number of certain disadvantages. To begin with, this system is initially very sensitive to the quality of diesel fuel. The ingress of even small foreign fractions or impurities can cause immediate damage to the pump, nozzles and other elements.
- Also, CRDi motors have a fairly high cost, which greatly increases the final price of a vehicle with a similar power plant... We add that the design of the Common Rail power system itself is complex, since for well-coordinated work, the design includes many electronic sensors.
This feature almost completely excludes the possibility of simple garage repairs. Diagnostics and / or troubleshooting requires the mandatory availability of expensive special tools, stands and equipment.
This means that it is possible to fully diagnose, repair, adjust or service the CRDI engine power system only under conditions dealerships or at large third-party service stations. At the same time, it is important not only to have the necessary equipment, but also qualified personnel who specialize in Common Rail.
- In parallel with this, for CRDi and Common Rail, there is often an urgent need to purchase expensive spare parts, since modular replacement is preferable. It becomes clear that for the above reasons, the cost of any work will be high.
Let's summarize
Based on the above information, it becomes clear why, in the CIS, many car owners still mistakenly consider the Common Rail diesel engine power system to be an extremely unreliable solution. Immediately, we note that the point is not in the system itself, but in the quality of domestic fuel and the level of service of a car with such engines.
It should be remembered that the Common Rail elements are made with high precision, that is, even the smallest foreign particles are not allowed to enter the system. Under conditions of extremely high pressure, such parts are quickly damaged after using low-quality fuel, and their replacement involves certain difficulties and significant costs.
In other words, if the driver had previously operated a diesel engine with a conventional injection pump, then no problems could arise. In this case, after changing the car to power unit with Common Rail, breakdowns could appear very quickly.
The fact is that, out of habit, the car continues to be filled with fuel of dubious quality at the nearest gas station, additional additives are poured into the tank in the cold season, etc. Also, not all drivers pay due attention to the quality of fuel filters and their replacement intervals.
It becomes clear that if a motor with a simple injection pump worked more or less normally in such conditions, then the Common Rail will fail much faster. Also, the appearance of failures will require in-depth diagnostics. At the same time, it is not always possible to quickly establish the cause.
The system actively uses many electronic sensors, activators, valves and other elements. Diagnostics involves checking the DPKV, the pressure sensor in the fuel rail, temperature sensors, etc. In parallel, you need to check the solenoids and a number of other elements.
Finally, we add that it can also be difficult to find a service station. The fact is that on the territory of the CIS, there is a shortage of qualified personnel for the diagnosis and repair of Common Rail.
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The first generation Sorento is still very well remembered. It has become a bestseller of its kind. Despite the fact that the first Sorento looked more like an SUV, it was a real SUV with a frame and gearbox. Unfortunately, in endurance tests, serious and costly malfunctions surfaced: the gearbox failed. rear axle and a turbocharger.
During the test while driving Kia sorento 2.2 CRDi was visited by 33 drivers from the editorial staff of the Polish branch of the German magazine "Auto Bild". For 100 700 km of the way, the car has seen cities, gravel and highways. The crossover was often fully loaded, but within acceptable limits. The car survived the winter in the Alps and the terrible heat in Croatia. Result: in addition to the disorienting navigation, later replaced under warranty, and the false ambient temperature sensor, no breakdowns or mechanical faults were identified. It was a little cold in the car in winter. The large SUV trunk was just right for editorial photographers, who always carried a lot of equipment, and for hobbyists. winter species sports who prefer to relax with the whole family.
"Economical - consumption diesel fuel below 8 liters, no oil consumption, comfortable enough, plenty of space and good makings outside the asphalt "- such positive reviews assembled a tested crossover after a trip to Croatia.
Further in the logbook read: “On slopes and rocks, the SUV confidently moves forward. Only occasionally did the front wheels lose contact with the ground. When driving along an unpleasant serpentine, there was no crackling or noise in the cabin. The engine runs clean. A large hatch that doesn't draw in too much air is thankfully not a source of annoying wind noise. "
But during the expedition to Croatia, several minor flaws were discovered. So the trunk curtain stopped folding, and the xenon light ignition unit of the right headlight refused. The navigation system software was outdated. Xenon headlights shine high even after corrections carried out as part of the planned Maintenance 60,000 km. Often at night they blinked in response high beam oncoming drivers. Unfortunately, the xenon light reflector automatically selects the optimal vertical angle of illumination.
Once we got into an unpleasant situation when the keys were left in the ignition switch of a car with the engine turned off. central locking blocked all doors. The driver had to get into the cabin through a hatch, which fortunately was open. The question arises: why electronic system locks door locks when the key is in the ignition.
In turn, the high test editor states: “The seats are comfortable, the back does not hurt even after 500 km of movement without stopping. But, unfortunately, after 70,000 km, the driver's seat has a slight backlash - when accelerating, it deviates slightly back. "
Other disadvantages: the USB port is slightly loosened, and when the lever is released parking brake, it often remains on the penultimate "tooth", which is why the movement begins with slightly tightened pads. A warning beep helps to correct the mistake.
Other editors, after a long journey, praised the fuel-efficient diesel, consuming just 8.7 L / 100 km at 140 km / h. But it was not without reproaches: the sound of a running engine seemed to some too similar to a "tractor" one, and the washer fluid tank was emptied at a record pace. Also marked noisy work pendants. By the end of the test, the leather seats showed clear signs of wear. The same was observed on the gear lever. At the end of the test, when the gears were switched on, an incomprehensible rattle appeared. One of the testers noted too much freewheeling noise from the A-pillars.
Nevertheless, all praised the Kia Sorento: "Powerful engine, smooth running, pleasant and safe handling, acceptable level of comfort." Despite the fact that the car ages twice as fast during the tests, Sorento made it to the finish line without a single mechanical failure.
"Kia-Sportige-2.0CRDi-AT-Premium", from 1,379,900 rubles, CAR from 12.80 rubles / km
As a riding instructor recently explained to me, the main purpose of thoroughbred horses is to race. Due to their explosive nature, excessive energy, they are not suitable for ordinary amateurs. These four-legged aristocrats need daily gallop relief and the hand of a master, otherwise the consequences can be unpredictable. Indeed, even their heart is larger and more powerful than that of horses of other breeds, their lungs are larger.
It was this information that for some reason came to my mind when I found myself at the wheel of a 184-horsepower "Sportage". Calm rhythm of everyday life road traffic, whose average speed does not exceed 50 km / h, he definitely does not like it. My thoroughbred horse even started up the hill so that just hold on, and instantly reacted to any pressing of the accelerator pedal, every minute trying to overtake the ride that had suddenly become unusually slow. He did it so briskly and playfully that it was almost impossible to resist the urge to play pranks.
Height adjustment and lumbar support to help the driver find a comfortable fit
However, it is not surprising. The aluminum R-series diesel four, which Sportage (and its ix35 cousin) received in 2009, is the pride of the Kia and Hyundai engineers. Equipped with a turbine with an aftercooler and a third-generation Common Rail injection system from Bosch, it delivers 136 horsepower in its quietest version. But the variable geometry of the turbine blades made it possible to increase the power by 48 hp. with., and the torque at 63 N.m. Considering that the mass of the 184-horsepower car has not increased by a single gram, it is clear where such an impressive vigor appeared in the character of such a "Sportage".
True, at good speeds in the car, the noise of the wheels and the sounds from the cars passing by is well heard. And the crossover's suspension is pretty stiff. Cracks and small potholes in the asphalt do not interfere, but on more serious obstacles "Sportage" begins to rumble noticeably, and the fifth point feels well the road seams and holes. But all the maneuvers on the road, my four-wheel drive "Kia" performed easily and naturally.
The 18-inch rims suit the Sportige very well. However, on our roads, wheels that are smaller by an inch, perhaps, should be recognized as much more practical.
Just do not expect special efficiency from such a fast horse. And in any case, the wonderful six-plus liters per hundred, which is promised by the official characteristics. My "Sportage", equipped, by the way, with everything that can be placed in a car, and even with the heater working at full capacity, ate at least 10-11 liters on average. After all, such a powerful and fast car I just want to drive, so my purebred stallion begins to whip "diesel fuel" with buckets. Remember that the Arabian horses in the stables of the sheikhs are fed with hay, which is transported by air from Canada. So that…
So the diesel "Sportidge", which reaches a hundred in 9.8 seconds, is prepared exclusively for those who do not want to put up with the calm character of his younger diesel brother and do not agree to a petrol horse. This stallion is for those who want the fastest and fastest version of all the existing ones. At the same time, the buyer has no choice: if he wants a nimble diesel engine, then a premium set of several dozen necessary and not particularly options with four-wheel drive and he is obliged to purchase it “automatically”, having paid 1,379,900 rubles for it. And the brother of our purebred horse is not supposed to have such a configuration at all, the ceiling of the 136-horsepower "Sportage" is a version of "Laksheri". It does not have a panoramic roof, leather interior and a parking lot, and instead of 18-inch wheels are installed per inch smaller in diameter.
We decided:
The most powerful diesel "Sportage" will delight its owner with impressive agility and almost exhaustive equipment. True, you will have to pay for this with a ruble: it is 80 thousand more expensive than the equally richly equipped gasoline and 130 thousand less powerful diesel counterpart.
