2002 Chevrolet Express / GMC Savana 4.3L Van Service Manual

• Covers 2002 Chevrolet Express and GMC Savana 4.3L V6 engine unit repair, with separate intake-manifold disassembly and assembly procedures for the L35 and LU3 fuel-meter configurations.
• Documents complete internal repair work: engine-block inspection, cylinder boring and honing, piston and connecting-rod service, crankshaft and bearing checks, and final lower-end assembly.
• Details cylinder-head disassembly, valve-guide reaming, valve and seat grinding, spring testing, valve-train inspection, and left- and right-bank head installation with tightening-sequence illustrations.
• Handles camshaft and balance-shaft work in depth, including bearing removal and installation, timing-chain and sprocket service, shaft indexing, crankshaft reluctor-ring placement, and distributor alignment.
• Includes oil-pump overhaul, oil-pan and filter-adapter service, rear-main-seal installation, water-pump and exhaust-manifold repair, thread repair, and L35/LU3 intake-system inspection.
• Provides a 513-page PDF with 422 numbered figures, three fastener-tightening specification tables, three engine-mechanical specification charts, and dedicated sealer, adhesive, lubricant, and special-tool references.

This manual covers bench-level repair of the 2002 4.3L V6 used in Chevrolet Express and GMC Savana vans. It is suited to professional engine builders and experienced technicians with an approved engine stand and lifting device, precision measuring equipment, torque wrenches, and a torque-angle meter. The material starts with engine identification for Tonawanda- and Romulus-built units, then follows the engine from external component removal through inspection, machining, assembly, and final component installation.

Internal Engine Repair and Machining

The lower-end sections go well beyond routine gasket replacement. They cover block cleaning and inspection, cylinder-bore measurement, boring and honing, piston-pin and ring service, connecting-rod alignment checks, crankshaft journal inspection, main- and rod-bearing clearance measurement, and crankshaft end play. Separate procedures address camshaft bearings, the balance-shaft bearing and bushing, crankshaft rear oil seal and housing, oil-gallery and core plugs, and oil-pump disassembly, pressure-relief-valve inspection, and reassembly.

Cylinder-head coverage includes teardown, deck and spring inspection, valve-stem and guide measurement, guide reaming, valve and seat grinding, stem-seal installation, and reassembly. The valve-train material covers hydraulic roller lifters, pushrods, one-piece rocker-arm supports, and roller-pivot rocker arms. A 2002 new-product section identifies the revised water-pump seal and thermostat, the change from ball-pivot to roller-pivot rocker arms, and cylinder heads with dry rocker-bolt holes.

L35 and LU3 Intake Configurations

The intake-manifold chapters separate the L35 Central SFI poppet-nozzle arrangement from the LU3 MFI injector arrangement. Each variant receives its own fuel-meter-body, injector or nozzle, fuel-pipe, MAP sensor, EGR valve, throttle-body, thermostat outlet, and upper-manifold disassembly and assembly coverage. The LU3 section also identifies the bracket change required when converting from the L35 SFI layout and illustrates the injector-line routing needed to avoid upper-manifold interference.

Figures, Tools, and Reference Data

Useful drawings include the Upper & Lower Intake Manifold View, Measuring Crankshaft Bearing Clearance, Installing Balance Shaft Using J 36996 & J 8092, Tightening Cylinder Head Bolts in Proper Sequence, Aligning Distributor Rotor Segment with Number 6 Pointer, and Engine Lubrication. The tool appendix illustrates factory tools and equivalents such as J 33049 Camshaft Bearing Service Kit, J 38834 Balance Shaft Service Kit, J 23523-F Balancer Remover and Installer, J 35621-B Rear Main Seal Installer, J 36660-A Torque Angle Meter, and J 43690 Rod Bearing Clearance Checking Tool.

The specification material supplies component-specific torque data, torque-angle strategies, mechanical dimensions, wear limits, clearance checks, sealant selection, and tightening sequences. It also flags non-reusable fasteners, gaskets, seals, O-rings, and retainers where applicable.

The repair cautions are specific. Abrasive pads or power tools used on gasket surfaces can leave grit that the oil filter cannot remove, causing internal engine damage. The manual also warns that mismatched connecting-rod caps or reused valve-train parts installed in the wrong locations can disrupt established wear patterns, while sealant in blind bolt holes can hydraulically lock a fastener and damage the fastener or casting.

This is an engine unit-repair manual, not a complete vehicle service manual. It does not cover engine removal from the van, chassis systems, wiring diagrams, or full fuel-system diagnosis. Because the work involves a stripped engine, compressed valve springs, heated connecting rods, compressed air, and heavy components, use the specified protective equipment and verify that the engine stand and lifting device are properly rated before beginning repair work.