Nissan VQ37VHR

The Nissan VQ37VHR is a 3.7 l (3,696 cc, 225.53 cu.in.) V6 4-stroke natural aspirated gasoline engine from Nissan VQ-family. The engine is producted on Nissan’s Iwaki factory since 2007. The VQ37VHR engine was honored by Ward’s 10 Best Engines list in 2008.

The VQ37VHR 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 VQ37VHR engine is equipped with CVTC (eVTC), VVEL system and NDIS (Nissan Direct Ignition System) with individual coils on each spark plug.

Compression ratio rating is 11:1. Cylinder bore and piston stroke are 95.5 mm (3.76 in) and 86.0 mm (3.38 in), respectively. It produces from 330 PS (242 kW, 325 HP) at 7000 rpm on the European version of Infiniti FX37 and EX37 up to 355 PS (261 kW, 350 HP) at 7600 rpm on Nissan Fairlady Z (Nismo version). The maximum torque is 374 Nm (38.13 kg·m, 275.8 lb·ft) at 5200 rpm.

The breakdown of the engine code is as follows:

• VQ – Engine Family
• 37 – 3.7 Liter Displacement
• V – VVL (Variable Valve Lift)
• HR – High Response and High Revolution

General information

Cylinder block

The VQ37VHR has an aluminum block with a four-bearings crankshaft supported system. The crankshaft journals are finished with a polishing tape to produce a mirror-like finish. The result is a thorough reduction in friction on these bearing surfaces of key engine components. Pistons have asymmetrical skirts with molybdenum coating.

The cylinder bore is 95.5 mm (3.760 in), piston stroke is 86.0 (3.386 in) mm and compression ratio rating is 11:1. The Nissan VQ37VHR motor has two compression and one oil control rings. The connecting rod’s length is 149.5 mm (5.88 in)

Cylinder head

The cylinder head is made of strong, light aluminum alloy which gives it good cooling efficiency. The engine is equipped with CVTC (Continuous Variable Valve Timing Control) and VVEL (Variable Valve Event and Lift) systems.

VVEL operation principle: A rocker arms and two types of links open the intake valves by transferring the rotational movement of a drive shaft with an eccentric cam to the output cam. The movement of the output cam is varied by rotating the control shaft with a stepper motor and changing the fulcrums of the links. This makes the continuous adjustment of the amount of the valve’s lift, during the intake valve event in the four-stroke cycle, possible. CVTC and VVEL systems together control the valve phases and its valve events, allowing free-control of the valve timing and lift.

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 valves are 36.6 mm in diameter and the exhaust valves are 30.2 mm. The VQ37VHR 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: 105 Nm; 11.0 kg·m; 77 ft·lb
• Step 2: Loosen all bolts completely
• Step 3: 40 kg·m; 4.1 kg·m; 30 ft·lb
• Step 4: Turn all bolts 95°
• Step 5: Turn all bolts another 95°

Camshaft sprocket bolts

• Intake: 103 Nm; 11 kg·m; 76 ft·lb
• Exhaust: 123 Nm; 13 kg·m; 91 ft·lb

Problems and malfunctions

The Nissan VQ37VHR is reliable and durable, but sometimes the following problems can happen:

• High oil consumption. The VQ37VHR has a catalytic converter and it is very sensitive to the fuel quality. They produce ceramic dust, which damaging the cylinders sleeve and piston rings. As a result, the engine has low compression, high fuel, and oil consumption. Such an engine requires repair or replacement.
  To prevent this problem, you need to change the upper catalytic converters for high flow catalytic converter. It will decrease the ecological standard, but this problem will not happen.

• Engine overheating. This is not a common problem, but it happens from time to time. Check the radiator condition and expansion tanks of the cooling system for any leaks.

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 VQ37VHR motor life expectancy is 200,000 miles of mileage (300,000 km) or more.

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 27 sizes to range from 7.88 mm (0.3102 in) to 8.40 mm (0.3307 in), in steps of 0.02 mm (0.0008 in).

Example (exhaust valve):
R = 7.90 mm
M = 0.52 mm
N = 7.90 + (0.52 – 0.34) = 8.08 mm, so we need a valve lifter with identification mark 808.

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.