Hyundai KIA U2 diesel engine

Hyundai / KIA
U2
Manufacturer:	Hyundai / KIA
Production period:	2008 to today
Style:	four-cylinder
Engines:	1.1 L (1120 cc) to 1.7 L (1685 cc)
Cylinder firing order:	1-3-2 / 1-3-4-2

Hyundai KIA U2 is a series of four-cylinder diesel engines.

In September 2008, the manufacturer completed the development of the U2 series. Their use began at the end of the year in the Hyundai i20 . Thus began the classification of diesel engines in series. Previously, Hyundai / KIA led all diesel innovations under the original name and divided only gasoline engines in series. The U2 series first named the development status of a diesel. In the new series was initially only the 1.6 -l engine adopted, only in 2011 followed by the 1.1 -liter three-cylinder.were derived from the 1.6 liter in early 2010, a 1.4 l for small cars and in November a 1.7 L engine as an entry for SUVs and middle-class models. This engine will also be combined in 136-horsepower version until 2012 with an electric motor to the group's first diesel hybrid. The projected standard consumption for mid-range vehicles is 3 l / 100 km.  Like the gasoline-based full hybrid, it will use a lithium-polymer battery to store energy.

Development goal of the U2 series was an improved appearance of the drive. On the part of the engine, the noise level was lowered. The timing chain and cylinder head covers were identified as two main U series noise sources. As a result, the ideal shape and position of existing and additional reinforcing struts were determined by means of statistical experimental design . Also, the oil pan was recognized as a sound box and also changed shape. The result would be a noise level of 91 dB, which should be one percent below the previous series and up to 2 dB below all 1.6-liter diesel engines on the market in 2009.

Also in the environment of the U2 engine details were changed. For example, the newly developed six-speed manual transmission, which is available for the first time for U-engines, achieves 1.5 percent fuel savings through lower engine speeds. The effort required for switching was reduced by larger clutch plates, as well as the number of components whose manufacturing tolerances can add up less so and thus cause a more precise shift guide. 

Another component of the U2 motors is the "Battery Management System". It reduces or increases the use of the dynamo-identical alternator and thus the drive effort for the diesel engine. During braking, the alternator will produce power for the battery at full load, which will be picked up again at the next acceleration, to allow the alternator to run as smoothly as possible. The result was 2 percent less consumption. The BMS is standard and independent of the equipment with ISG. Like this, it reduces the standard consumption by 0.1 l / 100 km. 

However, the main features of the U-series change during the construction of their series. While these were among others the injection system and the added particulate filter in the first, the second is the ISG, the increase to 1800 bar injection pressure and the hybrid announced for 2012. All motor characteristics not mentioned here are therefore unchanged from the U series and as described there.

In June 2009, the U2 engines were the first and so far only Hyundai / KIA diesel engines a stop-start automatic transmission . The manufacturer calls her Idle Stop & Go. As the systems of other manufacturers , it stops the motor with gear idle ( Idle ) and very low speeds, so - for example in traffic queues - to save fuel. It restarts the engine as soon as the driver announces the next acceleration by pressing the clutch pedal. Technically, the starter motor was mechanically strengthened, thus quieter and designed with 300,000 cycles for six times more starting operations. 

Like all stop-start systems, the ISG checks some parameters to determine if it actually turns off the engine. As a result, the engine remains mostly consistently on winter short-haul.

• engine stop
  • No ISG-related error codes may be stored
  • Cooling water temperature must be above 45 ° C
  • Catalyst temperature must be above 200 ° C
  • Battery temperature must be between 2 ° C and 60 ° C
  • Battery charge level must be over 70%
  • The brake booster pressure must not be too low (due to too short a ride since the last stop)
  • The blower must not be at maximum level (would burden the battery)
  • The driver's door must be closed
  • The bonnet must be closed (endangered by rising engine belts)
  • The driver's seat belt must be worn
  • The ISG off switch to the left of the steering wheel must not be lit, ie pressed
  • The vehicle speed must be below 5 km / h
  • and at least once over 10 km / h after the last manual engine start.

• engine start
  • Clutch pedal must be operated more than 10% 

Injection and Pollutant Reduction 

The injection system was updated as in the first series after the start of production. For example, the 2010 debuted 1.4 and 1.7-liter sockets use a third-generation common-rail system. It supplies the fuel with up to 1800 bar instead of 1600 bar in the system of all 1.6-l versions. Their densification also dropped from 17.3 to 17.0 . This reduces material pressure and thus the temperature in the cylinder. This results in less nitrogen oxides. Their allowable amount but also remains in the achieved by these engines Euro 5 standard in three times a gasoline engine.

An important step towards engines with a perfectly homogeneous mixture is achieved by the 1.7-liter engine with the application of a variable valve opening time. The system, which has been increasingly installed on the manufacturer's gasoline lines since 2004, varies the opening time of the valves on the inlet and outlet side (" Dual -CVVT"). Together with the already existing swirl control an even more precise turbulence of the air is possible, into which the diesel is injected at the end of the compression. This is the U2 1.7 with its debut in the KIA Sportage the world's second diesel engine with variable valve timing. Of this series is so far only the turbocharger of the 1.6 -l versions over 90 hp known, this is a Garrett GTB1444VZ.  Its turbine with 14 mm on the exhaust side is one millimeter smaller than in the turbocharger of the first series and thus faster to rev up. However, DC was its variable geometry on which also the turbo of the 1.7-liter engine. The 1.4- and 1.1-l turbochargers are known to lack this. They have a fixed geometry and thus necessarily a pressure relief valve ("wastegate").

Problems

For some 1.6 -liter U2 engines from July 8, 2009 to April 30, 2010, a long start was required, especially in cold conditions, followed by out-of-round engine operation. Likewise, it could come to strong blue-white smoke, as long as the engine was cold. Cause were two problems with the glow plugs. These were sometimes too short, so that part of the thread of their support in the cylinder exposed. In it could collect soot, which then bothered at the next start a correct functioning of the glow plugs. In other engines caused the glow plugs, however, a short-circuit on the cylinder head. As a result, the glow plug fuse interrupted its power supply, the glow plugs were thus out of service. In warm temperatures, these are not activated, so that this is recognizable only in cold weather. In the case of vehicles with particle filters, in most cases only the abnormal starting behavior is recognizable; the smoke is largely filtered out by the soot present in the particle filter. The replacement of the glow plugs is covered by the manufacturer's warranty. In engines from April 30, 2010, improved glow plugs will be used ex-works, eliminating problems.

Data 

Use 

Listed are the world's built-U2 motors for each model, not all countries are listed in all configurations listed.

Hyundai Accent

• Accent RB
  • D4FB (128 hp, U2 series): 2011 to today
  • D4FC (90 hp, U2 series): 2011 to today

Hyundai i20

• i20 PB
  
  • D4FB (115 hp, U2 series): 2008 to today
  • D4FC-L, D4FC (75, 90 hp, U2 series): 2010 to today

Hyundai ix20

• ix20 JC
  • D4FC-L, D4FC (77, 90 hp, U2 series): 2010 to today

Hyundai i30

• i30 FH (from Korea) / FDH (from the Czech Republic)
  
  • D4FB-L, D4FB (90, 115, 126 PS, U2 series): 2009 to today

Hyundai i40

• i40
  • D4FD-L, D4FD (115, 136 hp, U2 series): from summer 2011

Hyundai ix35

• ix35 LM
  • D4FD-L (115 hp, U2 series): 2010 to today

KIA Carens

• Carens UN
  • D4FB (128 hp, U2 series): 2010 to today

KIA cee'd

• cee'd ED
  
  • D4FB-L, D4FB (90, 128 hp, U2 series): 2009 to today

KIA Forte

• D4FB (128 hp, U2 series): 2009 to today

KIA Kia Optima

• Optima TF
  • D4FD-L (115 hp, U2 series): from 2012

KIA Rio

• Rio UB
  • D3FA (70 PS, U2 series): from autumn 2011
  • D4FC (90 hp, U2 series): from autumn 2011

KIA soul

• Soul AM
  • D4FB (115, 128 hp, U2 series): 2009 to today

KIA Sportage

• Sportage SL
  • D4FD-L (115 hp, U2 series): 2010 to today

KIA Venga

• Venga YN
  • D4FC-L, D4FC (75, 90 hp, U2 series): 2010 to today
  • D4FB (115, 128 hp, U2 series): 2009 to today