VQ40DE Engine


nissan vq40de

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Nissan VQ is a 2.0-4.0L V6 piston motor, keeping aluminum block with dual overhead camshaft featuring 4 valves per cylinder plus aluminum heads. It’s supplied with the brand’s EGI/ECCS sequential multi-port fuel injection while its subsequent variations keep different modifications of variable valve timing and direct fuel injection. The latter are often referred as NEO-Di.

Motors of this lineup were built as alternatives to VQ line. Being rather successful, they were among 10 best engines for many years, according to Ward version.

 

Nissan VQ40DE Engine review

Nissan VQ40DE, released by Decherd Powertrain Plant in Tennessee, United States, is a 4.0L naturally aspirated V6 60°  four-cycle gasoline motor.

Keeping lightweight aluminum block with balanced 4-bearings crankshaft, motor features double overhead camshaft with 4 valves per cylinder. VQ40DE is provided with variable intake system, CVTC system on inlet part, Nissan Direct Ignition System with separate coils for every spark plug (keeping platinum tips) plus multi-point fuel injection system.

While cylinder bore is 95.5 mm (3.76 inches), piston stoke is 92.0 mm (3.62 inches). Compression index equals to 9.7.

Motor reaches output from 261 hp (265 PS or 196 kW) to 275 hp (279 PS or 205 kW) with torque from 381 Nm (38.8 kg/m or 281 lb/ft) to 390 Nm (39.8 kg/m or 288 lb/ft) depending on VQ40DE version.

VQ40DE specs

Manufacturer Decherd Powertrain Plant
Also called VQ40
Production 2005-present
Cylinder block alloy Aluminum
Configuration V6
Valvetrain DOHC
4 valves per cylinder
Piston stroke, mm (inch) 92 (3.62)
Cylinder bore, mm (inch) 95.5 (3.76)
Compression ratio 9.7
Displacement 3954 cc (241.3 cu in)
Power output 195 kW (265 HP) at 5,600 rpm
198 kW (269 HP) at 5,600 rpm
Torque output 381 Nm (281 lb·ft) at 4,000 rpm
390 Nm (288 lb·ft) at 4,000 rpm
Redline
HP per liter 67.0
68.0
Fuel type Gasoline
Weight, kg (lbs)
Fuel consumption, L/100 km (mpg)
-City
-Highway
-Combined
for Pathfinder
18.7 (13)
10.5 (22)
13.5 (17)
Turbocharger  Naturally aspirated
Oil consumption , L/1000 km
(qt. per miles)
up to 0.5
(1 qt. per 1200 miles)
Recommended engine oil 5W-30
5W-40
10W-30
10W-40
Engine oil capacity, L (qt.) 5.1 (5.4)
Oil change interval, km (miles) 5,000-10,000
(3,000-6,000)
Normal engine operating temperature, °C (F)
Engine lifespan, km (miles)
-Official information
-Real

400,000+ (250,000)
Tuning, HP
-Max HP
-No life span loss
400+



Applications

  • Nissan Pathfinder
  • Nissan Xterra
  • Nissan Frontier
  • Nissan NV
  • Suzuki Equator

Engine code meaning

  • VQ – Engine Family
  • 40 – 4.0 Liter Displacement
  • D – DOHC (Dual Overhead Camshafts)
  • E – Multi Point Fuel Injection

Cylinder Block

VQ40DE features aluminum cylinder block equipped with 4-bearings crankshaft supported system, forged steel rods, micro-finished monoblock forged crankshaft plus molybdenum covered pistons. Diameter of crankshaft main journal equals to 70 mm (2.75 inches) while the one of crankpin is 54 mm (2.12 inches).

Compression index of 9.7 is reached thanks to 95.5 mm (3.76 inches) cylinder bore and 92.0 mm (3.62 inches) piston stroke. Additionally, motor keeps 2 compression and 1 oil control rings plus 165.85 mm (6.53 inches) connecting rods.

Cylinder block alloy Aluminium
Compression ratio: 9.7:1
Cylinder bore: 95.5 mm (3.760 in)
Piston stroke: 92.0 mm (3.622 in)
Number of piston rings (compression / oil): 2 / 1
Number of main bearings: 4
Cylinder inner diameter (standard): 95.500-95.510 mm (3.7598-3.7602 in)
Piston skirt diameter (standard): 95.480-95.490 mm (3.7590-3.7594 in)
Piston pin outer diameter: 21.989-21.995 mm (0.8657-0.8659 in)
Connecting rod bushing inner diameter: 22.000-22.006 mm (0.8661-0.8664 in)
Connecting rod big end diameter: 57.000 mm (2.2441 in)
Connecting rod center distance: 165.82-165.92 mm (6.5283-6.5323 in)
Piston ring side clearance: Top 0.045-0.080 mm (0.0018-0.0031 in)
Second 0.030-0.070 mm (0.0012-0.0028 in)
Oil 0.065-0.135 mm (0.0026-0.0053 in)
Piston ring end gap: Top 0.23-0.33 mm (0.0091-0.0130 in)
Second 0.33-0.48 mm (0.0130-0.0189 in)
Oil 0.20-0.50 mm (0.0079-0.0197 in)
Crankshaft main journal diameter: 69.975 mm (2.7549 in)
Crankpin diameter: 53.974 mm (2.1250 in)
Crankshaft center distance: 45.96-46.04 mm (1.8094-1.8126 in)



Cylinder Head

Being built of sturdy but lightweight aluminum alloy, cylinder head provides motor with a great cooling effect. Intake camshafts keep hydraulically driven Continuous Variable Valve Timing Control. One primary and two secondary chains manage camshafts. Primary timing chain forwards rotational movement from the crankshaft to inlet camshafts while secondary ones unite intake and exhaust rag-wheel on every head.

Inlet valves are 37.0-37.3 mm (1.45-1.46 inches) while exhaust ones are 31.2-31.5 mm (1.22-1.24 inches). Camshafts duration is 240/244 degrees. Having no hydraulic tappets, VQ40DE regulates valve clearance with especial valve tappets.

Block head alloy Aluminium
Valve Arrangement: DOHC, chain drive
Cylinder head height: 126.3-126.5 mm (4.97-4.98 in)
Valves: 24 (4 valves per cylinder)
Intake valve timing
(Intake valve timing control-OFF):
240°
Exhaust valve timing: 244°
Valve head diameter: INTAKE 37.0-37.3 mm
EXHAUST 31.2-31.5 mm (1.228-1.240 in)
Valve length: INTAKE 96.46 mm (3.7976 in)
EXHAUST 93.99 mm (3.7004 in)
Valve stem diameter: INTAKE 5.965-5.980 mm (0.2348-0.2354 in)
EXHAUST 5.955-5.970 mm (0.2344-0.2350 in)
Valve spring free length: INTAKE 47.07 mm (1.8531 in)
EXHAUST 47.07 mm (1.8531 in)
Exhaust camshaft journal diameter: №1 25.935-25.955 mm (1.0211-1.0218 in)
№2, 3, 4, 5 23.445-23.465 mm (0.9230-0.9238 in)
Camshaft cam height: INTAKE 45.465-45.65 mm (1.7900-1.7974 in)
EXHAUST 45.075-45.265 mm (1.7746-1.7821 in)



VQ40DE engine problems and reliability

Being a pretty reliable motor, Nissan 4.0 V6 engine still may have some shortcomings:

  1. Excess oil consumption. Catalytic converter condition is very dependable on fuel quality. It may create ceramic dust able to damage cylinder sleeve along with piston rings. Consequently, motor will get decreased compression, exceeding the amount of fuel and oil consumed. This malfunction means that motor must be either repaired or substituted. The preventive measure is replacement of upper cat converters for a high flow cat converter. You will avoid this trouble though your vehicle will be less eco-friendly.
  2. Motor’s 3 timing chains may run for 150,000 miles (200,000-250,000 kilometers) with no faults. However, it’s important to regulate valve clearance after every 60,000 miles (90,000 kilometers) are run. Upon the whole, VQ40DE is able to serve for 200,000 miles (300,000 kilometers).



Dan Hoffman

Dan is a co-founder of Engineswork. He knows everything about internal combustion engines. Ask your questions in comments down below this article - he will be glad to help you anytime.

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