Nissan QR25DE 2.5L L4 Remanufactured Engine – 2005-2006 FWD

Description

Stabilize connecting rod bearing clearances and maintain dynamic combustion chamber sealing under 175 lb-ft continuous torque demands across severe front-wheel-drive fleet transit rotations with the Nissan QR25DE FWD Remanufactured Engine. Tailored for 2005 to 2006 Altima and Sentra commercial chassis, this 16-valve DOHC inline-four powerplant provides reliable acceleration and endurance across heavy metropolitan schedules.

Die-cast aluminum block architecture integrates centrifugally cast iron dry sleeves finished to an Ra 25 micro-inch deck surface specification. A precision-balanced forged steel crankshaft rotates within a structural lower bedplate, driving forged steel connecting rods and graphite-coated hypereutectic pistons. Sump capacity measures 4.8 quarts in a cast aluminum pan, while high-velocity oil passages ensure prompt lubrication distribution across an overall dry engine mass of 290 lbs.

Key Features of Nissan QR25DE FWD

Commercial parcel fleets buy Nissan QR25DE FWD remanufactured engine packages to ensure sustained route punctuality and lower routine operating expenses. Counterbalance shaft synchronization eliminates unwanted engine vibrations to enhance vehicle drivability under heavy payloads.

• Continuous intake variable valve timing advances camshaft overlap for rapid off-the-line vehicle acceleration
• Double overhead camshafts operate sixteen valves via direct-acting bucket tappets for valve stability
• Multi-layer steel cylinder head gaskets maintain combustion seals against continuous thermal cycles
• Plateau diamond honed cylinder bores eliminate piston ring blow-by and oil vapor emissions
• High-flow internal trochoid oil pump provides 55 PSI cruising lubrication to protected bearings
• Dual counterbalance shafts cancel secondary vibrations to preserve front transaxle mount integrity
• Nissan QR25DE FWD long block units pass rigid non-destructive ultrasonic flaw testing

Dynamic Power Thermal Boundaries

This motor outputs 175 horsepower at 6000 RPM alongside 180 lb-ft continuous torque at 4000 RPM using an exact 9.5:1 compression ratio. Dynamic cylinder cranking compression tests between 175 and 185 PSI across all four cylinders. Normal coolant operating temperatures hold between 185°F and 205°F, supported by 18 PSI hot idle oil pressure and 55 PSI cruising pressure. Radiator thermal rejection capacity measures 2750 BTU per minute under Severe Commercial Fleet duty cycle standards.

Driveline Crankshaft Interface Parameters

The rear crankshaft flange uses a six-bolt flywheel mounting pattern with an engineered 0.826-inch pilot counterbore diameter. Front crankshaft snout measures 1.102 inches with a machined Woodruff keyway slot for timing sprocket retention. Dial indicators measure crankshaft axial thrust endplay between 0.003 and 0.007 inches across all finished builds.

Break-In Protocol Servicing Rules

Technicians must prime internal engine oil passages with an external pressure tank before turning the ignition key to protect fresh bearing surfaces from dry friction. Conduct a twenty-minute cam run-in procedure at 2000 RPM using high-zinc break-in lubricant. This engine is not engineered for aftermarket turbochargers, nitrous systems, or trailer towing weights exceeding vehicle chassis ratings.

• Inspect fluid reservoirs and accessory belts each shift
• Change motor oil and replace spin-on filter every 4500 miles
• Inspect cooling system hoses and radiator every twelve months

Commercial Guarantee Container Contents

Protected by our 3-Year 100000-Mile commercial fleet warranty for verified transport operations. The heavy wooden container holds the remanufactured long block engine, high-capacity oil pump, complete engine install gasket kit, spark plug tube seals, and a certified dynamometer qualification inspection report.