Nissan QR25DE Specifications
| Engine Model: Nissan QR25DE |
| Engine Type: 4-cycle inline 4-cylinder DOHC 24-valve CVTC liquid-cooled gasoline |
| Total Displacement: 151.8 cu.in (2.49 L) |
| Rated Engine Power: 165-180 Hp (122-133 kW) at 6000 rpm |
| Fuel System Type: Multi-point electronic fuel injection |
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The Nissan QR25DE engine is a 2.5-liter,
inline-four, four-stroke, water-cooled gasoline engine forming part of
Nissan’s QR-series. Introduced in the early 2000s, the QR25DE replaced
the earlier KA24DE in many markets and soon became one of Nissan’s most
widely used mid-displacement engines. It powers a broad range of
vehicles including the Nissan Altima, Sentra SE-R Spec V, Rogue,
X-Trail, Teana, and various global-market models.
The QR25DE emphasizes fuel economy, mid-range torque, emissions control,
and long-term reliability. It features an aluminum block and head, DOHC
architecture, continuously variable valve timing, multi-point fuel
injection, and a robust timing-chain-driven valvetrain. Designed to
handle both commuter driving and moderate performance use, the engine
delivers stable power output while maintaining low maintenance
requirements.
The early QR25DE engines (particularly 2002-2006 models) experienced
issues related to catalytic converter breakdown and intake-system
resonance, but later revisions strengthened internal components,
optimized port design, upgraded pistons and rings, improved
counterbalance shafts, and refined engine control mapping. The improved
structure made later QR25DE releases exceptionally durable. The engine
is widely regarded as a dependable workhorse with a long service life
when serviced properly.
The QR25DE displaces 2,488 cc (151.8 cu in). Bore is approx. 89.0 mm
(3.50 inches), stroke is approx. 100.0 mm (3.94 inches), giving it a
long-stroke profile tailored for torque production at low and mid rpm.
Compression ratio varies by model year and market but ranges between
9.5:1 - 10.5:1. Idle speed is 700-750 rpm. The firing order is 1-3-4-2.
Redline varies by calibration, generally 6,200-6,500 rpm.
Factory output values vary:
- Standard QR25DE: 165-175 hp at 5,600-6,000 rpm
- Nissan SE-R Spec V versions: 175-180 hp at 6,000-6,200 rpm
- Torque: 170-180 lb-ft (230-245 Nm) at 4,000 rpm
The engine block is aluminum with cast-in steel cylinder liners. The
long-stroke configuration emphasizes torque delivery. The crankshaft is
forged steel and supported by five main bearings.
Connecting rods are forged steel, and pistons are aluminum alloy with
molybdenum-coated skirts. The piston crowns are optimized for efficient
combustion, supporting clean burn and strong torque.
Later QR25DE revisions strengthened:
- Piston rings
- Rod design
- Counterbalance shaft assembly
- Timing-chain tensioner
- Crankcase ventilation
These improvements significantly increased long-term reliability. The
deep-skirt block design ensures rigidity under load.
The QR25DE uses an aluminum DOHC cylinder head with four valves per
cylinder.
Features include:
- Dual overhead camshafts
- Continuously Variable Valve Timing Control (CVTC) on the intake cam
- Timing chain with oil-pressure-operated tensioner
- Roller rocker arms
- Hydraulic valve-lash adjusters
The combustion chamber is designed for efficient swirl and tumble.
Intake and exhaust ports are shaped to maintain mixture velocity for
strong mid-range output. CVTC improves torque, throttle response, and
emissions control by optimizing intake timing across load conditions.
The QR25DE uses a multi-point electronic fuel injection (MPFI) system.
Major components:
- Electric in-tank fuel pump
- High-pressure fuel rail
- Multi-hole injectors
- Mass-airflow (MAF) sensor
- Electronic throttle body (drive-by-wire on most models)
- Fuel-pressure regulator (returnless systems used on many variants)
Fuel-pressure range: approx. 51-58 psi depending on the system.
The ECU controls injection based on:
- Crank-angle sensor
- Camshaft-angle sensor
- Throttle-position sensor
- Intake-air temperature sensor
- Coolant-temperature sensor
- Oxygen sensors (upstream and downstream)
- Knock sensor
The mixture is finely tuned for fuel economy and emissions compliance.
The lubrication system is a full-pressure wet-sump system.
Specifications:
- Oil capacity: 4.3-4.6 liters (4.5-4.9 US qt)
- Oil pressure: approx. 45-65 psi at 3,000 rpm; approx. 15-20 psi at
idle
- Recommended oil: 5W-30 or 0W-20 synthetic depending on climate and
revision
A crankshaft-driven trochoid oil pump circulates oil through crankshaft
bearings, camshaft journals, timing-chain components, piston cooling
jets, and valvetrain. Later revisions improved oil-control rings and
crankcase ventilation to reduce oil consumption. A spin-on full-flow oil
filter is used.
The QR25DE uses a liquid cooling system
consisting of:
- Belt-driven centrifugal water pump
- Aluminum-core radiator
- Electrically controlled cooling fans
- Thermostat
- Coolant passages in block and head
Specifications:
- Thermostat begins opening: approx. 82°C (180°F)
- Fully open: approx. 95°C (203°F)
- Cooling-system capacity: 6.5-7.0 liters (6.8-7.4 US qt)
The system is designed for tight thermal control to support emissions
and efficiency.
| Intake and Exhaust Systems |
The induction system includes:
- Air-filter housing
- Paper air filter
- Intake snorkel
- Mass-airflow sensor
- Electronic throttle body
- Long-runner plastic intake manifold
The intake manifold geometry promotes torque-rich mid-range performance.
Resonance tuning varies between performance and economy versions.
The exhaust layout includes:
- Exhaust manifold (stainless or cast depending on version)
- Close-coupled catalytic converter
- Underfloor catalytic converter
- Oxygen sensors (pre- and post-cat)
- Muffler system
Earlier QR25DE engines had issues with catalytic material breaking down
and being ingested into the combustion chamber; later designs
strengthened the catalyst and altered intake routing to prevent this.
The ignition system is electronically controlled and uses coil-on-plug
technology.
Components include:
- Four individual ignition coils
- Platinum or iridium-tipped spark plugs
- Crankshaft position sensor
- Camshaft position sensor
- ECM ignition mapping
Spark-plug gap measures approx. 0.9-1.1 mm (0.035-0.043 inches). Spark
timing is dynamically adjusted for knock prevention and efficiency.
- Length: 680-720 mm (26.8-28.3 in)
- Width: 600-630 mm (23.6-24.8 in)
- Height: 650-700 mm (25.6-27.6 in)
Dry weight: 135-155 kg (298-342 lb) depending on configuration and
accessories
Recommended intervals:
- Oil and filter: every 5,000-10,000 km (3,000-6,000 mi)
- Air filter: every 20,000 km (12,000 mi)
- Spark plugs: every 60,000-100,000 km
- Coolant: every 2-3 years
- Drive belts: inspect every 20,000-30,000 km
- Fuel filter: non-serviceable in most models (in-tank)
Compression readings:
- Approx. 160-190 psi
- Cylinder variation: less than 10 percent
Idle speed: approx. 700-750 rpm. Proper maintenance helps avoid CVTC and
chain-tensioner issues.
- Cylinder-head bolts: approx. 75-85 lb-ft (102-115 Nm)
- Main-bearing-cap bolts: approx. 55-65 lb-ft (75-88 Nm)
- Connecting-rod bolts: approx. 28-35 lb-ft (38-48 Nm)
- Flywheel bolts: approx. 75-85 lb-ft (102-115 Nm)
- Intake-manifold bolts: approx. 18-22 lb-ft (24-30 Nm)
- Exhaust-manifold nuts: approx. 25-30 lb-ft (34-40 Nm)
- Oil-drain plug: approx. 25-30 lb-ft (34-40 Nm)
- Spark plugs: approx. 15-20 lb-ft (20-27 Nm)
The QR25DE engine powers many Nissan
vehicles including:
- Nissan Altima
- Nissan Sentra SE-R Spec V
- Nissan X-Trail T30 and T31
- Nissan Rogue (early generations)
- Nissan Serena (global variants)
- Nissan Teana (regional models)
- Nissan Frontier (select markets)
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