Nissan CR12DE

The Nissan CR12DE is a 1.2 l (1,240 cc, 75.66 cu.in.) straight-four 4-stroke natural aspirated gasoline engine from Nissan CR-family.

The CR12DE features a lightweight aluminum block with five-bearings crankshaft and aluminum head with two camshafts (DOHC) and four valves per cylinder. The CR12DE engine has an electronic throttle, variable valve timing system VTC on the intake camshaft, EGR system and electronic ignition with individual coils on each spark plug.

Compression ratio rating is 9.8 or 9.9:1. Cylinder bore and piston stroke are 71.0 mm (2.795 in) and 78.3 mm (3.083 in), respectively. It produces from 80 to 110 PS (59-81 kW; 79-109 HP) of horsepower and 121 to 134 Nm (12.4-13.7 kg⋅m, 89.2-98.8 lb⋅ft) of torque.

The breakdown of the engine code is as follows:

• CR – Engine Family
• 12 – 1.2 Liter Displacement
• D – DOHC (Dual Overhead Camshafts)
• E – Multi Point Fuel Injection

General information

Cylinder block

The Nissan CR12DE has an aluminum block with a five-bearings crankshaft supported system. The cylinder bore is 71.0 mm (2.79 in), piston stroke is 78.3 mm (3.083 in) and compression ratio rating is 9.8:1 or 9.9:1. The CR12DE motor has two compression and single oil control rings.

The connecting rods center distance is 129.5 mm (5.098 in). The crankshaft main journal diameter is 44.97 mm (1.77 in) and crankpin diameter is 39.97 mm (1.53 in). The piston height is 34.3 mm (1.350 in).

Main bearing cap bolts tightening procedure and torque specs:

• Step 1: 24.5-30.3 Nm; 2.5-3.0 kg·m; 18-22 ft·lb
• Step 2: Turn all bolts 95-100°

After securing bearing cap bolts, make sure crankshaft turns smoothly by hand.

Connecting rod bearing nut

• Step 1: 13.7-15.7 Nm; 1.4-1.6 kg·m; 10-11.5 ft·lb
• Step 2: Turn nuts 45-50°

Crankshaft pulley bolt

• 132-152 Nm; 14-15 kg·m; 98-112 ft·lb

Flywheel (M/T) or Drive plate (A/T) fixing bolts

• Flywheel: 83-93 Nm; 8.5-9.5 kg·m; 61-69 ft·lb
• Drive plate: 93-103 Nm; 9.5-10.0 kg·m; 69-75 ft·lb

Cylinder head

The cylinder head is made of light aluminum alloy, each camshaft is supported by five bearings. The CR12DE engine is equipped with an intake valve timing controller (integral with cam sprocket) which continuously adjusts the phase of intake valve according to driving conditions, improves both low and mid-range engine torque and high-speed range engine output, and brings about low emission and low fuel consumption. The camshafts are driven by the timing chain.

Intake valves are 27.5 mm (1.083 in) in diameter, intake duration is 224°, and the exhaust valves are 22.5 mm (0.886 in), exhaust duration is 216°. The Nissan CR12DE motor does not have hydraulic lifters, so special valve lifters are used to adjust the valve clearance.

The engine has a plastic intake manifold. The CR12DE is equipped with EGR (Exhaust Gas Recirculation) system. This system returns a portion of the exhaust gas to the intake side to reduce fuel consumption and minimize emission.

Head tightening procedure and torque specs:

• Step 1: 61.7-71.7 Nm; 6.3-7.3 kg·m; 46-52 ft·lb
• Step 2: Loosen all bolts completely
• Step 3: 22.5-32.5 kg·m; 2.3-3.3 kg·m; 17-23 ft·lb
• Step 4: Turn all bolts 90-95°

Camshaft sprocket bolts

• 78-88 Nm; 8.0-9.0 kg·m; 58-65 ft·lb

Problems and malfunctions

The main problem of this engine is the loss of power, rough idle. It happens because of the front catalytic converters. They wear out because of poor quality fuel, and their ceramic dust through the EGR system is absorbed by the engine. As a result, it grinds the cylinder walls, and then the dust gets into the oil system and spreads all over the engine.

Maintenance data

Valve clearance adjustment data

Calculate the thickness of new adjusting valve lifter so valve clearance comes within specified values.

R = Thickness of removed valve lifter
N = Thickness of new valve lifter
M = Measured valve clearance

Intake:
N = R + [M – 0.30 mm (0.012 in)]
Exhaust:
N = R + [M – 0.33 mm (0.013 in)]

Valve lifters are available in 35 sizes range from 3.00 mm (0.1181 in) to 3.68 mm (0.1449 in), in steps of 0.02 mm (0.0008 in).

Example (intake valve):
R = 3.10 mm
M = 0.52 mm
N = 3.10 + (0.52 – 0.30) = 3.32 mm, so we need a valve lifter with identification mark 32.

Vehicle applications

Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.