Nissan VQ20DE

The Nissan VQ20DE is a 2.0 l (1,995 cc, 121.73 cu.in.) natural aspirated V6 60° 4-stroke gasoline engine from Nissan VQ-family.

The VQ20DE features a lightweight aluminum block with a fully balanced four-bearings crankshaft and two aluminum heads with two camshafts (DOHC) and four valves per cylinder. The Nissan VQ20DE engine is equipped with NISSAN EGI (ECCS) electrically controlled gasoline injection device and NDIS (Nissan Direct Ignition System) with individual coils on each spark plug.

Cylinder bore and piston stroke are 76.0 mm (2.992 in) and 73.3 mm (2.886 in), respectively. Compression ratio rating is 9.5:1 or 10:1.

There were three generations of VQ20DE:

• First generation (1994-1998): The Nissan VQ20DE engine produced 155 PS (114 kW, 153 HP) at 6,400 rpm and 186 Nm (18.9 kg⋅m, 137 lb⋅ft) at 4,400 rpm.
• Second generation (1998-2001): The engine produced 160 PS (117 kW, 157 HP) at 6,400 rpm and 197 Nm (20.0 kg⋅m, 145 lb⋅ft) at 4,000 rpm.
• Third generation (after 2001): It produced 150 PS (110 kW, 147 HP) at 6,400 rpm and 186 Nm (18.9 kg⋅m, 137 lb⋅ft) at 4,400 rpm.

After 1999 the Nissan VQ20DE engine received prefix “NEO”.

The breakdown of the engine code is as follows:

• VQ – Engine Family
• 20 – 2.0 Liter Displacement
• D – DOHC (Dual Overhead Camshafts)
• E – Multi Point Fuel Injection

General information

Cylinder block

The VQ20DE has an aluminum cylinder block with a four-bearings crankshaft supported system, forged steel connecting rods, a micro-finished one-piece forged crankshaft. The crankshaft journal diameter is 60 mm (2.36 in), the crankpin diameter is 45 mm (1.78 in).

The cylinder bore is 76.0 mm (2.992 in), piston stroke is 73.3 mm (2.886 in) and compression ratio rating is 9.5:1 or 10:1. The Nissan VQ20DE motor has two compression and one oil control rings. The connecting rod’s length are 147.7 mm (5.81 in)

Main bearing cap bolts tightening procedure and torque specs:

• Step 1: 32-38 Nm; 3.3-3.9 kg·m; 24-28 ft·lb
• Step 2: Turn all bolts 90-95°

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

Crankshaft pulley bolt

• Step 1: 39-49 Nm; 4.0-5.0 kg·m; 29-36 ft·lb
• Step 2: Put a paint mark on the crankshaft pulley
• Step 3: Again tighten by turning 60-65°, about the angle from one hexagon bolt head corner to another.

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

• 83-93 Nm; 8.5-9.5 kg·m; 61-69 ft·lb

Cylinder head

The cylinder head is made of strong, light aluminum alloy which gives it good cooling efficiency. The camshafts are driven by single primary and two secondary chains. The primary timing chain transmits the rotational movement from the crankshaft to the intake camshafts, the secondary chains connects intake and exhaust sprocket on each head respectively.

The intake valve diameter is 29.0 mm (1.14 in) and the exhaust valve diameter is 24.0 mm (0.94 in). The VQ20DE motor does not have hydraulic lifters, so special valve lifters are used to adjust the valve clearance.

Head tightening procedure and torque specs:

• Step 1: 98 Nm; 10.0 kg·m; 72 ft·lb
• Step 2: Loosen all bolts completely
• Step 3: 34-44 kg·m; 3.5-4.5 kg·m; 25-33 ft·lb
• Step 4: Turn all bolts 90-95°
• Step 5: Turn all bolts another 90-95°

Camshaft sprocket bolts

• 119-128 Nm; 12.1-13.1 kg·m; 88-95 ft·lb

Problems and malfunctions

The Nissan VQ20DE is reliable and durable. The engine has three timing chains, their service life is about 150,000 miles of mileage (200,000-250,000 km). The valve clearance needs to be adjusted every 60,000 miles of mileage (90,000 km). The Nissan VQ20DE life expectancy is 200,000 miles of mileage (300,000 km).

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 – 0.34 mm (0.013 in)]

Valve lifters are available in 55 sizes from 2.10 mm (0.0827 in) to 2.72 mm (0.1071 in).

Example (exhaust valve):
R = 2.20 mm
M = 0.52 mm
N = 2.20 + (0.52 – 0.34) = 2.38 mm, so we need a valve lifter with identification mark 238.

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.