The engine 2.0 CDTI (A20DTH) is Italian. It is developed on the basis of the Fiat 1.9 CDTI power unit, which we have already told you about. The upgraded 2-liter engine debuted in 2008 on the Lancia Delta. Since then, it has been installed on a huge number of cars of such brands as Alfa Romeo, Fiat, Jeep, Opel, Saab and Suzuki. Today we will talk about this engine on the example of the unit A20DTH, removed from Opel Insignia.
The piston group of the 1.9 and 2.0 engines is different, because on the modernized engine the cylinder diameter is 1 mm larger, but the piston stroke remains the same. The difference in working volume is only 46 “cubes” (cc). We can also mention that the set of timing belt of most versions of this 2-liter engine is the same as for the motor 1.9 CDTI.
In general, modifications of the updated 2-liter turbodiesel for GM and Fiat cars are slightly different, because in the mid-2000s both automakers stopped cooperation. For example, a biturbo version of this engine with an output of 195 hp was created for Opel Insignia. And Italian engineers have made a 1.6-liter (D Multijet) from this 2-liter engine.
The technical characteristics of the engine Opel A20DTH 2.0 CDTi:
| Characteristics | Value |
|---|---|
| Exact volume | 1956 cm³ |
| Power system | Common Rail |
| Engine power | 160 – 170 hp |
| Torque | 350 Nm |
| Cylinder block | Cast-iron, in-line 4-cylinder (R4) |
| Cylinder head | Aluminum, 16 valves |
| Cylinder diameter | 83 mm |
| Piston stroke | 90.4 mm |
| Compression ratio | 16.5 |
| Engine features | Intercooler |
| Hydrocompensators | Yes |
| Transmission timing | Belt |
| Fasoregulator | No |
| Turbocharger | VGT (Variable Geometry Turbocharger) |
| Oil volume | 4.5 liters, 5W-30 |
| Fuel type | Diesel |
| Environmental class | Euro 5 |
| Example service life | 250,000 km |
| Engine weight | 190 kg |
Engine problems and reliability
The engine 2.0 CDTI turned out to be good, but it has one unpleasant feature, which leads to liners turning and jamming. Here is our motor, which we will disassemble, also gave a wedge. The problem and its consequences lie in the pallet, so very soon we will show and tell you everything in detail.
Intake manifold flaps
The intake manifold of the 2.0 CDTI engine is not without the filler flaps. The flaps cause trouble when their movement is restricted by soot and oil accumulated in the manifold. If something prevents the flaps from moving, the error P2015 is registered, but it does not affect the engine operation. The same error can occur in the case of malfunction of the servo drive of the flaps: when the teeth in the drive are destroyed or when the brushes of the electric motor are worn out.
Antifreeze channel in the intake manifold
In the intake manifold of the 2.0 CDTI engine (A20DTH) there is a channel for coolant. And it’s a very questionable solution. The inlet to the channel is located next to the air duct of one of the cylinders. Between them there is a small plastic jumper and two sealing rubbers. Usually, when the antifreeze channel gasket hardens, the liquid starts to flow outward along the block. But in the unfortunate circumstances, antifreeze can get into the intake channel.
In addition, often the manifold is simply cracked. The crack can be formed on its inlet part, and on the antifreeze channel. In this case, you have to buy the entire manifold. By the way, its replacement is very labor-intensive.
Turbine
The Garret turbocharger with vacuum geometry control is quite reliable, although there are enough cases of failure of its cartridge. What supercharger and motor response problems can also be related to a burst supercharged air supply pipe and a burst supercharger pressure relief valve.
Ignition spark plugs
There are two types of glow plugs on the 2.0 CDTI engine: regular glow plugs and glow plugs with a combustion chamber pressure sensor. The pressure sensor is required for engines with ecoFlex technology. According to this sensor, the control unit “sees” deviations in the combustion parameters of the fuel-air mixture and turns on the glow plugs to warm up the chambers. This approach helps to combat the formation of nitrogen oxides.
Leakage of heat exchanger O-rings
From the heat exchanger of the Opel 2.0 CDTI engine (A20DTH), located under the oil filter, already by the mileage of 50 000 – 70 000 km began to leak oil. To eliminate the leak, a couple of o-rings need to be replaced.
Fuel system
The entire fuel system, as on the predecessor – from Bosch. The fuel injectors and injectors are quite reliable and resourceful, easily repaired. The injectors are electromagnetic, it is desirable to install them with IMA-code prescription when replacing and after repair. However, this is not a mandatory procedure, because the fuel system is self-learning and can adjust to the parameters of new or used injectors without prescription.
Fuel pressure regulator
If the idle speed of the engine 2.0 CDTI began to float, there are problems with fuel pressure in the ramp, then it is worth cleaning and blowing the fuel pressure regulator installed on the fuel injector. In many cases, it is the culprit of uneven idling.
The EGR valve
On the 2-liter motor, the EGR valve is more complicated than on its predecessor. The valve tends to stick from accumulated soot and oily deposits. If the EGR valve jams in any of the positions, there are a variety of problems: from inability to start the engine or a strong “thrumming”, to a severe drop in power. Usually these symptoms occur suddenly and disappear after the engine is restarted.
Oil filter housing and cooler
The risk group includes all 2.0 CDTI engines with a single-pin pressure sensor. Motors with a three-pin sensor have not yet suffered from jamming. In addition, it is possible to “activate” the oil pressure readings on the on-board computer for such motors.
Oil pump and sensor feature
Until 2013, the 2.0 CDTI engine used a rotary oil pump, the feature of which is self-regulation. That is, the performance of such a pump does not depend on the engine speed, it always develops the necessary oil pressure. Probably, Opel engineers relied on this property of the oil pump and equipped early versions of the 2.0 CDTI engine with only an emergency oil pressure sensor. As the problem became apparent, they introduced a three-pin sensor that monitors oil pressure.
On the updated Opel Insignia with Start-Stop system, a vane oil pump is installed, the performance of which is controlled by a solenoid valve.
Causes of wedge engine Opel 2.0 CDTI
Of course, the reason for the turning of the main liners and wedging of the engine Opel Insignia lies in oil starvation. But why does it happen? There are different versions. The most common cause of oil starvation, about which the owners of not only Opel cars, but also owners of Fiat and Alfa Romeo with 2-liter and 1.6-liter turbodiesels produced before 2013 are talking both in Europe and here, is the subsidence or destruction of the sealing ring between the oil pump housing and the oil receiver tube. Over time, this ring begins to leak air from the crankcase cavity. This means that oil is sucked into the pump together with air. This is a prerequisite for oil starvation.
The A20DTH 2-liter turbodiesel can start to starve slowly, letting the driver know of low oil pressure on cold starts. But it can also just suddenly seize up. In most cases, this happens in highway or highway driving at high speeds and overtaking, when the liners lack lubrication due to air bubbles in the oil. It is recommended to change this seal every 100,000 km or 3 years, checking the condition of the liners.
Another version of the causes of oil starvation says that the oil pump jams the pressure reducing valve, which stops the release of excessive oil pressure. Because of this, the oil pump works at a prohibitive capacity and “sucks” too much oil out of the sump until it “breathes” air. In this case, the knees suffer instantly. This version explains why the 2-liter turbodiesel rotates the liners while driving at high speed or overtaking.
The third version speaks about the wear of the oil pump itself. Usually owners of Opel Insignia with this motor, doing preventive maintenance, change both the o-ring on the oil receiver and the oil pump. These two measures help to solve the problem with low oil pressure in the engine.