The 2.0L turbo-diesel engine (RPO LUZ) (Fig. 1) provides greater fuel economy than a comparably sized gasoline engine through greater thermal efficiency, a higher compression ratio and an unthrottled combustion process.

Fig 1

It features an iron cylinder block and a forged steel crankshaft, each designed to stand up to the greater cylinder pressures that come with a turbo-diesel engine.

A lightweight aluminum cylinder head and aluminum intake manifold contribute to the engine’s comparatively low weight of 408 pounds (185 kg). The engine has been designed to reduce the noise and vibration often associated with earlier generation diesel cars.

A precise Exhaust Gas Recirculation (EGR) control system features a high-capacity cooler and bypass feature that enable the engine to meet U.S. and Canadian diesel emissions regulations. The exhaust after-treatment system is similar to that used on Chevrolet’s heavy-duty trucks and vans equipped with the Duramax diesel.

Engine Oil

The Cruze Turbo Diesel uses dexos2. Oil meeting the requirements of the vehicle should have the dexos2 certification mark on the container. (Fig. 2) This certification mark indicates that the oil has been approved to the dexos2 specification.

 Fig 2

In the event that dexos2-approved engine oil is not available at an oil change or for maintaining proper oil level, it is acceptable to substitute engine oil that meets ACEA C3 of the appropriate viscosity grade.

Automatic Transmission

An AF40-6 transmission (RPO MDK) is used in the Cruze Turbo Diesel. It is an electronic 6-speed automatic transmission with lock-up. The transmission requires AW1 Transmision Fluid.

TIP: Do not use Dexron VI Automatic Transmission fluid as it is not compatible.

The transmission does not have an oil dipstick. The drain plug has an extra, central check plug for checking the level. (Fig. 3) It is connected to a rising tube that reaches up to the correct level in the transmission.

Fig 3

Fill the oil through the conventional oil filler plug until the level is correct and oil runs out of the check plug hole in the rising tube.

Diesel Emission Fluid (DEF)

The Cruze Turbo Diesel is equipped with a 4.9-gallon (18.5L) DEF tank that is accessible by lifting the load floor in the trunk. (Fig. 4) The fluid level in the DEF tank must be maintained for the vehicle to run correctly.

Fig 4

The DEF level indicator is displayed in the Driver Information Center (DIC).

When the DEF is getting low, the range will be displayed in the DIC. It is normal for the DEF range to vary based on vehicle and environmental driving conditions. When the low DEF message first displays at approximately 1,000 miles (1,600 km) of fluid range remaining, the fluid is approximately 3 gallons (11 liters) low.

The EXHAUST FLUID LOW SPEED LIMITED SOON message is displayed when the DEF range is less than 75 miles (120 km).

When the DEF tank is approaching empty, a EXHAUST FLUID EMPTY REFILL NOW message in the DIC will be displayed. If the DEF tank is not refilled, the ECM will begin to limit the vehicle to a maximum speed, starting at 65 mph (105 kph), and over time and mileage will reduce maximum speed to less than 10 mph (16 kph).

Only use DEF that is GM approved, or fluid containing the API certified or ISO 22241 label. The use of other fluids could damage the system, requiring costly repairs that will not be covered by the vehicle warranty.

Diesel Particulate Filter (DPF)

The Cruze Turbo Diesel DPF features a porous material that allows exhaust gas to pass through while trapping or filtering solid matter from the exhaust. Occasionally, depending on a number of factors monitored by the ECM, the DPF needs to be cleaned of accumulated solids. The ECM will initiate the cleaning process by warming the exhaust gas temperature. The accumulated particulate matter in the DPF will be safely converted to harmless gases, and the DPF will then be clean and ready again to trap or filter additional particulate matter.

Cleaning the DPF

When the ECM detects that the DPF is nearly full of particulates and that the vehicle is not being operated in a manner that would allow effective automatic DPF cleaning, the DIC displays DIESEL PARTIC FILTER IS FULL CONTINUE DRIVING or DIESEL PARTIC FILTER IS FULL CONTINUED DRIVING IS MANDATORY.

The driver is advised to follow the cleaning warning to prevent damage to the engine. The vehicle may need to operate continuously for up to 20 minutes and at speeds greater than 30 mph (48 kph) to clean the DPF effectively.

Fuel and Fuel Filter

The Cruze Turbo Diesel uses Ultra Low Sulfur Diesel Fuel (ULSF) only. The engine is equipped with a fuel filter to protect the engine from water and other diesel fuel contaminants. Water should be drained from the fuel filter when the DIC displays WATER IN FUEL CONTACT SERVICE.

Fuel filter cartridges must be replaced every 30,000 miles (48,000 km) or as indicated on the DIC. The fuel filter is located under the vehicle on the passenger side.

Auxiliary Electric Heater

A unique feature of the Cruze Turbo Diesel HVAC controls is the addition of an auxiliary electric heater that can be enabled by turning the temperature setting to full heat. This will improve the cabin heating in cold weather.

Engine Heater

The available engine heater can be used to provide easier starting and better fuel economy during warm-up in cold weather (at or below 0°F, -18°C). It should be plugged in at least four hours before starting. The electrical cord is located on the passenger side of the engine compartment.

– Thanks to Tod Stump