Nissan VK56DE Engine (VK56VD)
|Also called||Nissan VK56
|Cylinder block alloy||Aluminum|
4 valves per cylinder
|Piston stroke, mm (inch)||92 (3.62)|
|Cylinder bore, mm (inch)||98 (3.86)|
|Compression ratio||9.8 (VK56DE)
|Displacement||5552 cc (338.8 cu in)|
|Power output||224 kW (305 HP) at 4,900 rpm
239 kW (325 HP) at 5,200 rpm
298 kW (405 HP) at 5,800 rpm
300 kW (408 HP) at 6,000 rpm
|Torque output||522 Nm (385 lb·ft) at 3,500 rpm
533 Nm (393 lb·ft) at 3,400 rpm
560 Nm (413 lb·ft) at 4,000 rpm
550 Nm (406 lb·ft) at 4,400 rpm
|HP per liter||54.9
|Weight, kg (lbs)||227 (500)
|Fuel consumption, L/100 km (mpg)
|for Infiniti QX80
|Turbocharger|| Naturally aspirated
|Oil consumption , L/1000 km
(qt. per miles)
|up to 1.0
(1 qt. per 600 miles)
|Recommended engine oil||5W-30
|Engine oil capacity, L (qt.)||6.5 (6.9)|
|Oil change interval, km (miles)||5,000-10,000
|Normal engine operating temperature, °C (F)||–|
|Engine lifespan, km (miles)
-No life span loss
|The engine is installed in||Infiniti M56/Q70
VK56DE engine was introduced in 2003 on Armada and it was meant for US market. Moreover, it was produced in Decherd, Tennessee. VK56 was designed on basis of VK45DE, but its cylinder block was updated. Its height was enlarged to 232 mm, cylinder diameter – to 98 mm, also new crankshaft with 92mm piston stroke was installed, and VK56 connecting rods were 154.5 mm. Besides, new pistons were applied and compression ratio dropped to 9.8. All this let gaining displacement 5.6L, and along with that, the engine became more about low- and mid-range torque – the great advantage for the large cars.
There are two aluminium cylinder heads with 4 valves per cylinder on top. They use continuously variable valve timing control system (CVTCS) on intake camshafts. Also the engine is equipped with hydraulic lifters. Intake valves are 37 mm in diameter, and the exhaust are 31.5 mm.
VK56 cams have duration 232/230 deg, lift 8.8/8.8 mm. Timing chains on this engine may stretch eventually.
VK56 firing order is 1-8-7-3-6-5-4-2. OEM throttle body is 75 mm.
Later VK56VD engine appeared. It was noted for direct fuel injection system and continuous variable valve lift and timing system (VVEL) on all camshafts.
Along with it, other VK versions were produced, such as VK45DE and VK50VE.
Nissan VK56VD engine problems and malfunctions
1. Engine noise. More likely your right timing chain has stretched. You should watch it carefully, as such a problem may happen even if your car mileage is not high. Once it has appeared, change timing chain along with high pressure fuel pump, otherwise it will happen again. Changing the chain on VK56 is not an easy task. It involves disassembling the front of the car, what are extra expenses.
2. Loss of power, rough idle. This problem is similar to the one on VQ35, it happens because of the front catalytic converters. They wear out because of poor quality fuel, and their dust is absorbed by the engine. As the result, it grinds the cylinder walls, and then the dust gets into the oil system and spreads all over the engine. If it’s happened, you will have to buy new VK56 engine. In the countries with bad gasoline the problem is solved thanks to installing high flow cat converter and ECU reflash.
3. Loss of power, loss of dynamics. Once it has happened and these symptoms make progress, it means the fuel pump has probably failed. You should check it, and if this is the reason, purchase the new pump.
Early VK56DE engines were equipped with unreliable AC condenser radiator cooling fan. It might jam and cause overheating. Also the radiator should be washed every year to avoid overheating, otherwise cylinder head gaskets will break down. Besides, VK56 has not quite reliable high pressure fuel pump, usually it must be changed every 50,000-60,000 miles of mileage (80,000-90,000 km).
Sometimes air filter bodies may deform, and the dust and different small rubbish get into the engine and hasten its deterioration.
If you have unstable idling speed problem, then more likely you need to clean throttle body, it must help. Usually it is done after 60,000-70,000 miles of mileage (100,000-120,000 km).
After about 120,000 miles of mileage (200,000 km) your radiator may start leaking, that also happens.
To reduce the risk of such situations, use only high quality gasoline and engine oil, change the oil regularly and serve your car in time.
To gain more horsepower, you need to purchase JWT 256/256 cams, valve springs, cold air intake, 90 mm throttle body, headers and 3” performance exhaust system. Then adjust ECU aggressively, and you will gain about 340-350 horsepower.
If in addition to such aftermarket parts you will also equip the engine with Stillen supercharger kit, you will get more than 450 horsepower. Upon installing Stillen supercharger kit on stock engine, 430-440 HP and more than 640 NM torque will be available. This is the best option for large SUV.