Volkswagen CBAB Specifications
| Engine Model: Volkswagen CBAB |
| Engine Type: 4-cycle 4-cylinder DOHC 16-valve turbocharged liquid-cooled diesel |
| Total Displacement: 120.1 cu.in (1.96 L) |
| Rated Engine Power: 138 Hp (103 kW) at 4200 rpm |
| Fuel System Type: Common rail direct injection |
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The Volkswagen CBAB is a 2.0-liter, turbocharged inline
four-cylinder diesel engine produced from approximately 2008 through 2011 as
part of the EA189 engine family. The CBAB represented a significant
technological shift for Volkswagen’s 2.0-liter TDI lineup, transitioning from
the unit injector (Pumpe-Duse or PD) system to common rail direct injection.
The engine’s 1,968 cc displacement is achieved through a bore of 81.0 mm and a
stroke of 95.5 mm, a long-stroke configuration that favors low-end torque
generation - a characteristic essential for diesel applications in passenger
vehicles. The DOHC valvetrain with four valves per cylinder provides efficient
cylinder filling, while the Bosch EDC17 common rail system operates at injection
pressures up to 1,800 bar, enabling precise control over injection timing and
quantity.
The variable-geometry turbocharger (VGT) adjusts turbine vanes to optimize boost
response across the engine speed range, contributing to the engine’s broad
torque plateau from 1,750 to 2,500 rpm. The engine’s cast iron cylinder block
and aluminum cylinder head provide durability while managing weight. The timing
belt-driven valvetrain requires periodic replacement, and the water pump is
integrated into the timing belt drive system.
The CBAB’s reputation is defined by its refined operation relative to earlier PD
engines, its fuel efficiency, and its suitability for the compact SUVs and
sedans in which it was installed. However, the engine is noted for specific
service considerations, including intake manifold flap actuator failure, oil
pump drive hex shaft wear in early production units, and EGR valve soot
accumulation.
Production Period: 2008-2011
Engine Code: CBAB
Configuration: Inline four-cylinder (I4)
Displacement: 1,968 cc (120.1 cu.in)
Bore: 81.0 mm (3.19 in)
Stroke: 95.5 mm (3.76 in)
Firing Order: 1-3-4-2
Compression Ratio: 16.5:1
Combustion System: Common rail direct injection
Aspiration: Turbocharged and intercooler
Valvetrain: DOHC, 16 valves (4 per cylinder)
Engine Management: Bosch EDC17
Maximum Engine Speed: 5,000 rpm (governed)
Maximum Power: 138 hp (103 kW / 140 PS) @ 4,200 rpm
Maximum Torque: 236 lb-ft (320 Nm) @ 1,750-2,500 rpm
Emissions Standard: Euro 5 with diesel particulate filter (DPF)
The CBAB cylinder block is manufactured from cast iron,
utilizing a closed-deck design at the top of the cylinder bores to provide
structural rigidity under the high cylinder pressures generated by the common
rail injection system. The block features a deep-skirt design that extends below
the crankshaft centerline, contributing to reduced vibration and improved main
bearing alignment.
Five main bearings support the crankshaft, with the bearing caps secured using
high-tensile steel bolts. The cylinder bores are cast directly into the block
and are finished with a precision-honed surface. The crankshaft is constructed
from forged steel to withstand the torsional stresses of turbocharged diesel
operation. The block incorporates oil galleries drilled to supply pressurized
lubricant to the crankshaft, connecting rods, and cylinder head.
Piston cooling oil jets are integrated into the block, directing a continuous
stream of oil to the underside of each piston crown to manage combustion
temperatures. The engine mounting points are cast into the block to accommodate
the transverse or longitudinal orientation depending on the vehicle platform.
The cylinder head is manufactured from cast aluminum
alloy and features a dual-overhead-camshaft (DOHC) arrangement with 16 valves.
The valvetrain utilizes hydraulic lash adjusters and roller finger followers,
eliminating the requirement for manual valve clearance adjustments. The
camshafts are driven by a timing belt, with a spring-loaded automatic tensioner
maintaining proper belt tension. The intake valves measure 32.0 mm (1.26 in) in
diameter, while the exhaust valves measure 28.0 mm (1.10 in).
The combustion chamber is a pent-roof design with centrally positioned
injectors, optimized for the common rail system. The cylinder head incorporates
the intake ports on one side and exhaust ports on the opposite side, with the
intake ports designed to generate swirl within the combustion chamber to enhance
air-fuel mixing. The cylinder head gasket is a multi-layer steel design to
withstand the high compression pressures and thermal cycling inherent in
turbocharged diesel operation.
The fuel system utilizes a Bosch common rail direct
injection system with solenoid-type injectors, operating at maximum injection
pressures of up to 1,800 bar (26,100 psi). A high-pressure pump, driven by the
timing belt, delivers fuel to the common rail, which serves as a high-pressure
accumulator. The rail pressure is regulated by a pressure control valve, with a
pressure sensor providing feedback to the engine control unit. The solenoid
injectors deliver fuel directly into the combustion chamber with precise timing
and quantity control.
The injectors are capable of performing multiple injection events per combustion
cycle, including pilot injections for reduced combustion noise, main injection
for power delivery, and post-injections for particulate filter regeneration. A
fuel filter with an integrated water separator is mounted in the supply line,
and a hand-priming pump facilitates system priming after filter changes. The
fuel system is designed to operate with low-sulfur diesel fuel to protect the
high-pressure components and the DPF.
The lubrication system employs a wet-sump design with a
gear-type oil pump mounted within the front of the engine, driven by a hex shaft
from the crankshaft. The pump incorporates a pressure relief valve to maintain
consistent oil pressure across the engine speed range. Early production CBAB
units (pre-2010) are noted for a service consideration involving the hex shaft
drive, where wear can result in reduced oil pressure.
The pump draws oil from the sump through a screened pickup tube and delivers it
through a full-flow spin-on oil filter mounted on the cylinder block. The
filtered oil is distributed through internal galleries to the crankshaft main
bearings, connecting rod bearings, camshaft bearings, and the hydraulic lash
adjusters. Piston cooling oil jets are supplied from the main oil gallery. A
water-to-oil heat exchanger is integrated into the system to maintain oil
temperature within the optimal range. Total system capacity, including the
filter and cooler, is 4.3 liters (4.5 qt).
The cooling system is a pressurized water-cooled design
utilizing a crossflow aluminum radiator with plastic end tanks, sized to manage
the thermal load of the turbocharged diesel engine. A centrifugal water pump,
driven by the timing belt, circulates coolant through the cylinder block,
cylinder head, and radiator. The water pump is a service item replaced in
conjunction with the timing belt. A wax-element thermostat is positioned in the
coolant outlet housing, with a nominal opening temperature of 87°C (189°F).
The system incorporates an expansion tank to accommodate coolant expansion and
to facilitate air removal. An electric cooling fan, controlled by the engine
control unit, provides airflow across the radiator during low-speed operation
and stationary idle. The cooling system is designed to provide rapid warm-up to
reduce friction and fuel consumption during cold-start operation, with the EGR
cooler and oil cooler integrated into the circuit. Coolant capacity is 7.0 to
8.0 liters (7.4 to 8.5 qt) depending on the vehicle application.
| Intake and Exhaust Systems |
Intake System: The intake system consists of an air
cleaner housing with a replaceable dry-type filter element, a mass airflow
sensor, and an intake manifold constructed from composite plastic. The intake
manifold incorporates swirl flaps that adjust airflow velocity to optimize
combustion under varying load conditions. The swirl flap actuator is a known
service consideration, as wear can result in fault code P2015 and reduced engine
performance.
Exhaust System: The exhaust system utilizes a cast iron exhaust manifold
designed to withstand the high temperatures of turbocharged diesel operation.
The system incorporates a diesel oxidation catalyst, a diesel particulate filter
(DPF) for Euro 5 compliance, and an exhaust gas recirculation (EGR) system with
an EGR cooler. The EGR valve is subject to soot accumulation, particularly in
vehicles used for short-distance urban driving.
The engine is equipped with a 12-volt electrical
system. The starter motor is a high-torque reduction-gear type. The alternator
is belt-driven from the crankshaft pulley and provides charging current for the
battery and vehicle electrical loads. The Bosch EDC17 engine control unit
manages fuel injection, boost pressure, EGR operation, and DPF regeneration.
The CBAB is equipped with a variable-geometry
turbocharger (VGT), featuring adjustable turbine vanes that optimize boost
response across the engine speed range. The VGT actuator is electronically
controlled by the engine control unit. An air-to-air intercooler is mounted in
the front of the vehicle to reduce intake air temperature, increasing charge
density and reducing thermal stress on the engine.
Overall Length: 670 mm (26.4 in)
Overall Width: 620 mm (24.4 in)
Overall Height: 710 mm (28.0 in)
Dry Weight (complete engine): 165 kg (364 lbs)
Engine Oil: Synthetic SAE 5W-30 meeting VW 507.00
specification.
Oil Capacity (with filter change): 4.3 L (4.5 qt).
Oil Change Interval: 15,000 km (9,300 mi) or 1 year under normal conditions.
Oil Change Interval: 10,000 km (6,200 mi) under severe service.
Timing Belt Replacement Interval: 120,000 km (75,000 mi) or 5 years recommended.
Timing Belt Replacement Interval: 210,000 km (130,000 mi) official interval.
Fuel Filter: Replace at 40,000 km (24,800 mi) intervals; water separator drain
as required.
Coolant Capacity: 7.0-8.0 L (7.4-8.5 qt) depending on vehicle platform.
Coolant Specification: G12++ or G13 antifreeze (silicate-free, phosphate-free).
Valve Clearance: Hydraulic lash adjusters; no adjustment required.
Engine Idle Speed: 800-850 rpm.
Connecting Rod Cap Bolts (M8 x 1): 30 Nm (22 lb-ft)
Main Bearing Cap Bolts (M10 x 1.5): 50 Nm (37 lb-ft)
Cylinder Head Bolts (M12), Stage 1: 40 Nm (30 lb-ft)
Cylinder Head Bolts (M12), Stage 2: 80 Nm (59 lb-ft)
Camshaft Bearing Caps: 15 Nm (11 lb-ft) for M6
Camshaft Bearing Caps: 23 Nm (17 lb-ft) for M8
Intake Manifold to Cylinder Head: 10 Nm (7 lb-ft)
Exhaust Manifold to Cylinder Head: 25 Nm (18 lb-ft)
Flywheel/Flexplate to Crankshaft: 90 Nm (66 lb-ft)
Injector Holders: 20 Nm (15 lb-ft)
Glow Plugs: 15 Nm (11 lb-ft)
Turbocharger Mounting Nuts: 35 Nm (26 lb-ft)
Volkswagen Tiguan (5N, 2008-2011): CBAB engine in the
Tiguan 2.0 TDI 4Motion variants.
Volkswagen Passat B6 (2008-2010): Passat 2.0 TDI with CBAB engine.
Volkswagen Passat CC (2008-2011): Passat CC 2.0 TDI variants.
Volkswagen Eos (2008-2011): Eos 2.0 TDI variants in select markets.
Volkswagen Golf Mk6 (2008-2011): Golf 2.0 TDI 4Motion variants.
Audi A3 (8P, 2008-2011): Audi A3 2.0 TDI with CBAB engine in certain markets.
Volkswagen Caddy (2008-2011): Selected 2.0 TDI variants in European markets.
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