Oil System
General
The engines from the VEA family have an oil system with a variable oil pump, piston cooling and oil level sensor. Service interval depends on market and is wither 30 000 km or one year. The engine oil used is a fully synthetic oil with SAE 0W20 viscosity with designation VCC RBS0-2AE. The oil, which is specially developed for Volvo, must be used in all markets. The exception is the USA where, due to legal requirements on the market, ACEA A5/B5 5W30 is used instead. In order to optimize the engine's internal friction, the lubrication system has a fully variable oil pump. The oil pump's variable displacement contributes to reduced fuel consumption. None of the engines in the VEA family have a dipstick.
Oil pump
The oil pump is a vane pump where displacement can be varied steplessly as necessary. The oil pump is driven by the crankshaft via a chain. The chain is tensioned via a mechanical chain tensioner.
- Setting ring - vane pump
- Inner ring - vane pump
- Vanes (total of 6)
- Pressure spring
Variable oil pump
The oil pump is a vane pump where displacement can be continuously varied as necessary. Depending on the engine temperature, engine speed and torque output, the oil pump is controlled to an optimal pressure. Thereby, the power consumption from the oil pump can decrease, which eventually contributes to a reduction of fuel consumption and exhaust emissions.
The main component in the variable oil pump consists of a vane pump with an adjustable outer ring. Displacement of the pump changes according to the outer ring position. In its original position the pump produces its maximum flow and thus oil pressure, while when fully regulated it produces a reduced flow/pressure.
Control
Depending on engine temperature, engine speed (rpm) and torque output the oil pump is controlled to a current optimal pressure. Thereby, the power consumption from the oil pump can decrease, which eventually contributes to a reduction of fuel consumption and exhaust emissions. No control takes place at oil temperatures below 20 °C.
- <10 Nm
- 10-100 Nm
- 100-150 Nm
- 150-200 Nm
- >200 Nm
- Engine speed
- Oil pressure (bar)
Solenoid
Regulation of the outer ring is controlled by the engine control module (ECM) via a solenoid that is located in the oil pump housing. By controlling the flow of oil, the adjustment ring can be rotated, which changes the eccentricity and thus the vane pump's supply volume. The solenoid is controlled continuously via a PWM signal, where a fully regulated solenoid means a reduced displacement and an oil pressure of about 1.5 bar, while a solenoid in its second outer position provides a high displacement and an oil pressure of about 4.5 bar. If oil pump regulation should malfunction and the solenoid loses power, there is a safety system with a conventional ball and spring that regulates the oil pressure to a maximum of 6 bar.
Sensor, oil level
The engine does not have a conventional "mechanical" dipstick. Instead, the engine has an "electronic dipstick", i.e. an electric sensor. The sensor's measuring body consists of a wire made of an alloy consisting of iron, nickel and cobalt. This gives properties such as small expansion due to heat and little corrosion. The wire is placed in the sensor housing and is held in tension by a spring at the top. The measurement range of the sensor is 65 mm.
The image shows the measurement principle where different measurement ranges can be used for different information to the driver.
The principle is to close the circuit of the sensor for a short period. The oil's cooling effect affects the measurement wire's resistance. The higher the oil level, the greater the cooling effect. Level control occurs by means of the engine control module (ECM) applying a constant voltage of approx. 8V for a short period, approx. 750 ms. As the power supply to the measurement wire is constant, the current will vary depending on the sensor resistance. The current produces a corresponding voltage drop on a resistor connected in series with the measurement wire. The resistor is located in the engine control module (ECM). The voltage across the wire is registered at the beginning and end of the measurement. The difference in voltage corresponds to a certain level. When the oil level is low, the voltage difference is comparatively larger.
Measurement is carried out once per driving cycle, at the start of the driving cycle. The engine must be off for a certain amount of time to obtain the correct measurement result, i.e. nearly all of the oil must have run back to the oil pan.
The combined instrument panel (DIM) informs the driver about the current level and any action required via a graph and text message before the engine is started. See the owner's manual for further information. If the conditions for the measurement are not met, e.g. if the oil temperature has been too low, the tilt angle too large or the engine has not been switched off for long enough then the message "Not available" will appear.
Sensor oil pressure/oil temperature
The lubrication's pressure sensor is located in the engine block's intermediate section. The sensor is a combined oil pressure and oil temperature sensor. The sensor is powered with 5 V by the engine control module (ECM) and generates a PWM signal to the ECM. The PWM signal is split into three areas:
- Diagnosis
- Temperature
- Pressure
Inlet line with strainer
The plastic inlet line has a strainer that prevents large particles from reaching the oil pump.
Oil cooler
The oil passes via the oil cooler directly from the oil pump. The cooler is a plate oil cooler similar to that used on previous variants of Volvo engines where the area for oil and coolant is divided alternately through plates.