Nissan QG18DD

Nissan QG18DDThe Nissan QG18DD Neo Di is a 1.8 liter (1,769 cc, 107.94 cu in) straight-four 4-stroke natural aspirated gasoline engine from Nissan QG-family.

The Nissan QG18DD has a cast-iron cylinder block and aluminum alloy cylinder head with two overhead camshafts (DOHC). The engine uses a direct fuel injection system; a variable valve timing system on the intake side (CVCT); an electronic ignition system with individual ignition coil for each cylinder; an electronic throttle body.

An 80.0 mm (3.15 in) cylinder bore and 88.0 mm (3.46 in) piston stroke give the QG18DD engine a total of 1769 cc of displacement. The compression ratio rating is 11.0:1. The Nissan QG18DD engine produced 133 PS (97 kW; 130 HP) at 6,000 rpm of maximum output power and 174 N·m (17.7 kg·m, 128.2 ft·lb) at 2,800 rpm of peak torque.

The breakdown of the engine code is as follows:

  • QG – Engine Family
  • 18 – 1.8 Liter Displacement
  • D – DOHC (Dual Overhead Camshafts)
  • D – Direct Fuel Injection

General information

Engine Specifications
Engine codeQG18DD NEO Di
LayoutFour stroke, Inline-4 (Straight-4)
Fuel typeGasoline
Displacement1.8 L, 1,769 cm3 (107.94 cu in)
Fuel systemDirect Fuel Injection
Power adderNone
Power output133 PS (97 kW; 130 HP) at 6,000 rpm
Torque output174 N·m (17.7 kg·m, 128.2 ft·lb) at 2,800 rpm
Firing order1-3-4-2
Dimensions (L x H x W):

Cylinder block

The QG18DD motor has a cast-iron cylinder block, cylinder bore is 80.0 mm (3.15 in) and the piston stroke is 88.0 mm (3.46 in). The pistons are each fitted with two compression rings and a single oil ring. The compression ratio is 11.0:1.

The engine uses forged-steel connecting rods with 140.5 mm (5.53 in) length (center distance). The crankshaft main journal diameter is 49.95 mm (1.966 in) and pins journal diameter is 39.97 mm (1.57 in).

Cylinder block
Cylinder block alloyCast iron
Compression ratio:11.0:1
Cylinder bore:80.0 mm (3.150 in)
Piston stroke:88.0 mm (3.465 in)
Number of piston rings (compression / oil):2 / 1
Number of main bearings:5
Block Height:213.95-214.05 mm (8.4232-8.4271 in)
Cylinder inner diameter (standard):80.000-80.010 mm (3.1496-3.1500 in)
Piston skirt diameter (standard):79.965-79.975 mm (3.1482-3.1486 in)
Piston pin outer diameter:18.989-19.001 mm (0.7476-0.7481 in)
Piston ring side clearance:Top0.040-0.080 mm (0.0016-0.0031 in)
Second0.040-0.080 mm (0.0016-0.0031 in)
Oil0.010-0.185 mm (0.0004-0.0073 in)
Piston ring end gap:Top0.200-0.390 mm (0.0079-0.0154 in)
Second0.200-0.390 mm (0.0079-0.0154 in)
Oil0.200-0.690 mm (0.0079-0.0272 in)
Connecting rod center distance:140.45-140.55 mm (5.5295-5.5335 in)
Connectin rod small end inner diameter:19.000-19.012 mm (0.7480-0.7485 in)
Connectin rod big end inner diameter:43.000-43.013 mm (1.6929-1.6934 in)
Crankshaft journal diameter:49.956-49.964 mm (1.9668-1.9671 in)
Crankpin diameter:39.968-39.974 mm (1.5735-1.5738 in)
Crankshaft center distance:43.95-44.05 mm (1.7303-1.7342 in)

Cylinder head

The engine has an aluminum cylinder head with two chain-driven overhead single-piece cast camshafts and sixteen valves (four per cylinder). The QG18DD has a single timing chain. Intake valves are 30.0 mm (1.18 in) in diameter and the exhaust valves are 25.0 mm (0.99). This engine does not have hydraulic lifters, so special shims are used to adjust the valve clearance.

Cylinder head
Cylinder head alloyAluminum
Cylinder head height:118 mm (4.6456 in)
Valve Arrangement:DOHC, chain drive
Intake duration:
Exhaust duration:
Valve head diameter:INTAKE29.9-30.2 mm (1.177-1.189 in)
EXHAUST24.9-25.2 mm (0.980-0.992 in)
Valve length:INTAKE88.25 mm (3.4744 in)
EXHAUST88.62 mm (3.489 in)
Valve stem diameter:INTAKE5.465-5.480 mm (0.2152-0.2157 in)
EXHAUST5.445-5.460 mm (0.2144-0.2150 in)
Cam height:INTAKE40.705 mm (1.6026 in)
EXHAUST40.410 mm (1.5909 in)
Outer camshaft journal diameter:№127.935-27.955 mm (1.0998-1.1006 in)
№2-523.935-23.955 mm (0.9423 – 0.9431 in)

Head tightening procedure and torque specs:

  • Step 1: 29.4 Nm; 3.0 kg·m; 22 ft·lb
  • Step 2: 58.8 Nm; 6.0 kg·m; 43 ft·lb
  • Step 3: Loosen all bolts completely
  • Step 4: 29.4 Nm; 3.0 kg·m; 22 ft·lb
  • Step 5: Turn main bolts 50-55° or 58.8 Nm; 6.0 kg·m; 43 ft·lb

Maintenance data

Valve clearance (HOT)
Intake valve0.32-0.40 mm (0.013-0.016 in)
Exhaust valve0.37-0.45 mm (0.015-0.018 in)
Compression pressure
Standard13.8 kg/cm2 / 350 rpm
Minimun11.8 kg/cm2 / 350 rpm
Compression differential limit between cylinders1 kg/cm2 / 350 rpm
Oil system
Oil consumption , L/1000 km (qt. per miles)up to 0.5 (1 qt. per 1200 miles)
Recommended engine oil 5W-30
Oil type APISE, SF, SG, SH or SJ
Engine oil capacity (Refill capacity) With filter change 2.7 l
Without filter change 2.5 l
Oil change interval, km (miles)10,000 (6,000)
Oil Pressure, kPa (bar, kg/cm2 , psi) Idle speed: More than 98 (0.98, 1.0, 14)
2,000 rpm: More than 294 (2.94, 3.0, 43)
6,000 rpm: More than 392 (3.92, 4.0, 57)
Ignition system
Spark plug Standard: BKR5E-11 (NGK), RC10YC4 (Champion)
Hot: BKR4E-11 (NGL)
Cold: BKR6E-11 (NGK)
Spark plug gap1.0 – 1.1 mm (0.039 – 0.043 in)
Spark plug torque19.6-29.4 Nm (2.00-3.00 kg⋅m, 14.3-21.7 lb·ft)

Valve clearance adjustment data

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

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

N = R + [M – 0.37 mm (0.0146 in)]
N = R + [M – 0.40 mm (0.0157 in)]

Shims are available:

  • 11 sizes from 2.00 mm (0.0787 in) to 2.20 mm (0.0866 in), in steps of 0.02 mm (0.0008 in).
  • 46 sizes from 2.21 mm (0.0870 in) to 2.66 mm (0.1047 in), in steps of 0.01 mm (0.0004 in).
  • 50 sizes from 2.68 mm (0.1055 in) to 2.98 mm (0.1173 in), in steps of 0.02 mm (0.0008 in).

Example (intake valve):
R = 2.10 mm
M = 0.52 mm
N = 2.10 + (0.52 – 0.37) = 2.25 mm.

For adjustingFor checking
Intake0.32-0.40 mm (0.013-0.016 in)0.25-0.33 mm (0.010-0.013 in)0.21-0.49 mm (0.008-0.019 in)
Exhaust0.37-0.45 mm (0.015-0.018 in)0.32-0.40 mm (0.013-0.016 in)0.30-0.58 mm (0.012-0.023 in)

*: At a temperature of approximately 20°C (68°F)

Whenever valve clearances are adjusted to cold specifications, check that the clearances satisfy hot specifications and adjust again if necessary.

Vehicle applications

ModelYears Produced
Nissan Sunny (B15)1999-2006
Nissan Primera (P11)1999-2002
Bluebird Sylphy (N16)2000-2005
Nissan Primera (P12)2001-2007
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.

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1 Comment

  1. What other nissan models automatic gearbox can also be used on nissan primera QG18 DD? Please advise.

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