Eliminate chronic coolant contamination and valvetrain clicking by choosing this Pontiac Grand Prix 3.1L Remanufactured Engine long block. Engineered for front-wheel drive sedans, this 3.1L 6-Cylinder 12-Valve OHV powertrain restores factory vacuum and compression. A mandatory trade-off demands immediate cooling system vacuum bleeding to prevent hot spots and head gasket failure during initial thermostat opening cycles.

Cast iron engine block casting carries identifiers 227, 737, 150, 093, or 089 stamped on the driver side. Iron cylinder heads feature casting numbers 170 or 487 with SMOG holes positioned above 2 exhaust ports on each bank. Crated envelope dimensions measure 36in length by 36in width by 36in height with an engine weight of 267 lbs. Rotating hardware includes crank casting 981, nodular connecting rods, and a 4.5-quart oil pan.

Key Features of Pontiac 3.1L

Automotive repair facilities buy Pontiac 3.1L remanufactured engine assemblies to restore dependable transportation for suburban commuter sedans. This drop-in long block cures recurring lower intake manifold failures and provides balanced rotating operation across all 6 cylinders.

- Precision CNC deck surfacing creates an Ra 25 finish to ensure leak-free head gasket retention
- Diamond plateau cylinder honing creates uniform cross-hatch angles that seat piston rings within 500 miles
- Crankshaft casting 981 is precision micro-polished to hold 0.0003in TIR journal concentricity
- Align-honed main bearing saddles maintain 0.0012in oil clearance to protect bottom-end bearings
- Integrated air injection SMOG ports over exhaust runners maintain factory emissions compliance
- Reconditioned hydraulic roller lifters and pushrods eliminate valvetrain noise and maintain lift
- Rebuilt 12-Valve cylinder heads feature multi-angle cut valve seats holding 0.001in concentricity

Dyno Load Precision Machining Tolerances

Automated dynamometer spin testing verifies 175 HP output at 5,200 RPM and 195 ft-lbs continuous torque at 4,000 RPM under operational conditions. Machine shop tolerances enforce crankshaft journal runout below 0.0003in TIR and connecting rod bearing oil clearances at 0.0012in. Plateau-honed cylinder walls deliver compression between 175 PSI and 180 PSI across all 6 combustion chambers. Hot engine oil pressure measures 50 PSI at 2,500 RPM while regulated coolant operating temperatures hold steady at 195°F to verify water jacket flow integrity.

Vehicle Fitment Drivetrain Guide

This remanufactured long block fits 2003 Buick Century, Chevrolet Malibu, and Pontiac Grand Prix models equipped with the 3.1L 3135cc V6 engine and VIN code J. Mates to front-wheel drive transaxles paired with 4-Speed Automatic transmissions. Drivetrain note: this engine features air injection SMOG holes above 2 exhaust ports on each head and crank casting 981. It does not fit non-SMOG variations, larger 3.4L or 3.8L models, or 2004 newer chassis.

Installation Protocol Service Schedules

Install new aluminum-frame lower intake manifold gaskets and torque bolts to revised factory specifications to eliminate oil contamination. Flush heater cores and radiator passages to remove aged coolant sediment before ignition. Never operate this non-turbo long block in towing configurations exceeding vehicle gross weight limits or in custom boost setups without upgraded internal fasteners.

- Fill crankcase with 4.5 quarts of SAE 5W-30 break-in oil before running the starter
- Drain initial break-in lubricant and install a fresh oil filter after 500 miles
- Perform recurring synthetic blend motor oil and filter changes every 3,000 miles or 5,000 miles

Warranty Terms Core Return Policy

Every remanufactured GM engine includes our 3-Year Unlimited-Mile parts warranty for reliable consumer and commercial protection. Our freight department provides prepaid return shipping tags for your rebuildable core within an authorized 30-day window. Each crate delivers the long block, oil pan, front timing cover, valve covers, and complete installation guidelines.