Engine Mechanical - 5.0l v8 - VIN [M] Chevrolet Chevy Van G2500

ENGINE IDENTIFICATION

Engine is identified by eighth character of Vehicle Identification Number (VIN). VIN is stamped on a metal tag on top left end of instrument panel, near windshield. See ENGINE IDENTIFICATION CODES table.

Engine can also be identified by engine identification (ID) number. Number is stamped on front of cylinder block, immediately forward of right cylinder head or on left side of cylinder block, on engine-to-transmission mating flange.

ENGINE IDENTIFICATION CODES

VALVE CLEARANCE ADJUSTMENT

Note. Although valve clearance adjustment is not usually required (engine uses hydraulic valve lifters), perform the following procedure after servicing valve train.

1. Rotate crankshaft until cylinder No. 1 is at TDC of compression stroke. Loosen rocker arm adjusting nut on intake valve of cylinder No. 1 until lash is present. Tighten adjusting nut until lash is removed, then tighten adjusting nut one full turn.
2. Adjust remaining specified valves. See «VALVE CLEARANCE ADJUSTMENT»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. Rotate crankshaft 360 degrees to bring cylinder No. 6 to TDC of compression stroke. Adjust remaining specified valves.

VALVE CLEARANCE ADJUSTMENT

SHIFT CABLE ADJUSTMENT

Note. When installing shift cable, DO NOT pull shift lever ball stud forward of transmission shift lever ball stud.

"C" & "K" Pickup, Express, Savana, Sierra

1. Ensure transmission shift lever is in mechanical park position. Rotate control lever clockwise until it reaches it's final stop position. Apply parking brake. Raise and support vehicle.
2. Slide Black retaining clip forward on shift cable end far enough to allow White lock button to be pushed out. Push White lock button on shift cable end out far enough to free metal core adjust body inside cable end. DO NOT push White lock button completely out.
3. Inspect metal core adjust body on shift cable end for dirt or debris that may restrict its travel. If travel of metal core adjust body remains restricted, shift cable assembly must be replaced. Lower vehicle. Ensure parking brake is applied.
4. Turn ignition switch to ON position. Move transmission shift lever from Park to One and back to Park position 10 times. Place shift lever to Park. Turn ignition switch to OFF position. Raise and support vehicle. Ensure transmission control lever is in mechanical park position.
5. Rotate control lever clockwise until it reaches it's final stop position. Push White lock button in to secure core adjuster body inside shift cable end. Slide Black retainer clip rearward over shift cable end until it covers White lock button and locks in place over shift cable end. Ensure parking brake is applied. Lower vehicle.

TROUBLE SHOOTING

Note. To trouble shoot mechanical engine components, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

REMOVAL & INSTALLATION

Note. For reassembly reference, label all electrical connectors, vacuum hoses and fuel lines before removal. Also place mating marks on engine hood and other major assemblies before removal.

FUEL PRESSURE RELEASE

Disconnect battery terminals. Loosen fuel tank cap to relieve tank pressure. When ignition is turned off, an internal constant bleed in injection unit relieves fuel system pressure. No further pressure relief is required.

COOLING SYSTEM BLEEDING

1. Fill radiator to base of filler neck. Start engine. Place A/C-heater control in any position except MAX. Select highest temperature setting. Idle engine until lower radiator hose is hot.
2. Increase engine speed to 3000 RPM and then back to idle. Do this 5 times to expel any air trapped in system. Fill radiator as necessary. Install radiator cap. Allow engine to cool. Fill coolant recovery reservoir as necessary.
3. Crush and add 2 Coolant Sealant Pellets (GM P/N 3634621) or equivalent to radiator (if reservoir is not pressurized) or coolant reservoir (if reservoir is pressurized).

POWER STEERING BLEEDING

Note. If air was introduced into hydraulic system during servicing, bleed system. Aerated fluid, which appears Light Tan in color, results in poor steering performance and will cause pump damage.

1. Turn ignition off. Raise and support vehicle with front wheels off ground. Using steering wheel, turn wheels fully to left. Add power steering fluid to FULL COLD mark on dipstick. Turn wheels from side to side at least 20 times, but DO NOT touch steering stops. Add fluid as necessary to maintain level at FULL COLD mark.
2. Start engine. With engine idling, check fluid level. Add fluid as necessary to bring fluid level to FULL COLD mark. Return wheels to center position. Lower vehicle. Continue to run engine for 2 to 3 minutes to raise temperature of fluid and eliminate trapped air. Turn steering wheel in both directions.
3. Road test vehicle. Check for leaks. Ensure fluid level is at FULL HOT mark when fluid is stabilized at operating temperature.

Removal & Installation ("C" & "K" Pickup, Sierra)

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m__fuel-pressure-release) . Remove hood. Drain cooling system.
2. Remove air cleaner, accessory drive belt, fan and water pump pulley. Remove radiator and fan shroud. Disconnect heater hoses from engine. Disconnect fuel lines, electrical connectors, vacuum hoses, coolant hoses and control cables as necessary. Remove generator.
3. Remove A/C compressor and power steering pump with hoses attached and position aside (if equipped). Raise and support vehicle. Drain crankcase. Disconnect exhaust pipes from manifolds. Remove strut rods (if equipped). Remove flywheel cover and starter. Remove torque converter bolts (A/T).
4. Lower vehicle. Support transmission. Attach engine hoist. Remove bellhousing bolts. Remove engine mount through-bolts. Remove engine.

Installation ("C" & "K" Pickup, Sierra)

To install, reverse removal procedure. Fill crankcase and cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Removal (Commercial Van)

1. This procedure involves removing the engine and transmission as an assembly through side door. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m__fuel-pressure-release) . Drain cooling system. Remove engine cover and floor panel sections from inside vehicle.
2. Remove air cleaner, duct and exhaust heat stove pipe. Remove distributor cap and position aside. Disconnect all engine harness electrical connectors and position harness aside. Disconnect fuel lines from injection unit. Remove fuel line clamps from transmission and position fuel lines aside.
3. Disconnect hydraulic line from clutch slave cylinder. Disconnect ground strap from rear end of left cylinder head. Disconnect all transmission harness electrical connectors and position harness aside. Remove transmission shift lever (M/T).
4. Remove upper radiator hose, all accessory drive belts, fan, fan pulley, fan shroud and lower radiator hose. Remove engine oil filler tube. Raise and support vehicle. Disconnect exhaust pipes from manifolds. Disconnect battery cable from clamp on cylinder block.
5. Disconnect drive shaft from transmission. Remove transmission mount. Disconnect oil cooler lines from oil filter adapter. Disconnect oil cooler line clamps from engine. Attach engine hoist.
6. Remove engine mount through-bolts. Remove engine and transmission assembly through side door.

Installation (Commercial Van)

To install, reverse removal procedure. Fill crankcase and cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Removal (Express & Savana)

1. This procedure involves removing the engine and transmission as an assembly. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m__fuel-pressure-release) . Remove engine cover. Drain cooling system. Remove coolant recovery reservoir. Remove bumper headlight assemblies. Remove grille, lower grille valance, radiator hoses, upper radiator support and radiator. Remove engine cooling fan.
2. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove A/C condenser and radiator. Remove power steering pump with hoses attached and position aside (if equipped). Remove engine cover, air cleaner and injection unit. Remove generator and bracket.
3. Disconnect fuel lines, electrical connectors, vacuum hoses, coolant hoses and control cables as necessary. Remove fuel lines and bracket at rear of engine. Remove thermostat housing and oil filler tube. Remove generator and bracket. Remove intake manifold.
4. On A/T, remove transmission oil level indicator. On all vehicles, raise and support vehicle. Disconnect exhaust pipes from manifolds. Disconnect drive shaft from transmission. Disconnect transmission shift linkage and vehicle speed sensor connector from transmission.
5. If equipped, remove engine oil cooling lines from retaining blocks. Drain crankcase. Remove transmission mount bolts. Support engine with jack. Remove strut rods at engine mounts. Remove front engine mounts and place wood blocks between cylinder block and frame. On A/T, remove torque converter bolts. On all vehicles, lower vehicle. Remove bell housing to engine bolts. Attach engine hoist. Remove engine.

Installation (Express & Savana)

To install, reverse removal procedure. Fill crankcase and cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Removal

Note. Manufacturer does not provide a torque sequence for upper intake manifold.

1. Disconnect negative battery cable. Remove air cleaner assembly. Remove the wiring harness connectors and brackets and move aside. Disconnect cruise control cable (if equipped) and throttle cable at throttle body. Remove throttle cable bracket from upper intake manifold and move aside.
2. Remove the fuel lines from the intake to the rear of the block. Disconnect PCV hose at the upper intake manifold. Disconnect and remove the ignition coil and bracket. Disconnect and remove purge solenoid and bracket. Reference mark location of upper intake manifold studs for reassembly reference. Remove the upper intake manifold bolts/studs and upper intake manifold.

Installation

1. Using care not to pinch the injector lines between the upper and lower intake manifolds, install upper intake manifold using NEW upper intake manifold gasket. Note the marks made at disassembly for proper stud location. Install the two corner studs first in order to help align the two halves.
2. Tighten upper intake manifold bolts/studs in 2 steps, to specification, in a criss-cross pattern. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. To complete installation, reverse removal procedure.

1. Remove distributor cap. Mark distributor rotor in relation to distributor housing. Mark base of distributor housing in relation to intake manifold. Remove distributor.
2. Drain cooling system. Disconnect upper radiator hose at thermostat housing. Disconnect water pump by-pass hose and heater hose at intake manifold.
3. Remove EGR valve. Disconnect fuel lines at rear of lower intake manifold. Disconnect wiring harness.
4. Disconnect throttle cable and cruise control cable (if equipped). Unbolt throttle cable bracket from intake manifold. Move throttle cable bracket aside, with cables attached.
5. Unbolt transmission dipstick tube and remove/move aside as necessary. Remove PCV valve and disconnect vacuum hoses as necessary.
6. Remove serpentine belt. Unbolt A/C compressor/accessory bracketry and move aside as necessary to allow removal of intake manifold.
7. Remove lower intake manifold bolts, lower intake manifold and gaskets.

1. Apply a 3/16" (5 mm) bead of RTV (GM P/N 1052289) or equivalent to 4 sealing corners of block. (Scheme 36) Extend bead 1/2" (13 mm) up each cylinder head.
2. Apply Loctite® 242 (GM P/N 12345382) or equivalent to lower intake manifold bolt threads. Tighten bolts in sequence to specification. (Scheme 37) See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table.
3. To complete installation, reverse removal procedure. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m__cooling-system-bleeding).

Scheme 36

Scheme 37

Remove engine cover or floor panel. Remove negative battery cable. Remove oil level indicator tube and EGR inlet pipe. Remove spark plugs and spark pug heat shields. Remove exhaust pipe at manifold. Remove exhaust manifold bolts and exhaust manifold.

Install manifold. Tighten bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure.

Remove negative battery cable. Remove engine cover or floor panel. Remove intake manifold. See appropriate intake manifold section. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment and remove A/C compressor and bracket (if equipped). Remove generator and brackets. Remove spark plugs.

1. Clean gasket surfaces, bolt threads and bolt holes. If using steel head gasket, thinly coat both sides of gasket with sealant. DO NOT apply sealant to composite (steel/asbestos) head gaskets. Position head gasket on cylinder block. Ensure all holes align. Coat head bolt threads with GM Sealant (1052080).
2. Install cylinder head with bolts finger-tight. Tighten head bolts in sequence to specification. (Scheme 38) See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. Lubricate valve tip, rocker arm pivot and push rod socket with Molykote.
3. To complete installation, reverse removal procedure. Adjust valves. See «VALVE CLEARANCE ADJUSTMENT»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m__valve-clearance-adjustment) under ADJUSTMENTS.

Scheme 38

Remove negative battery cable. On Commercial Van, remove engine cover of floor panel. Remove PCV valve and tube. Remove EGR inlet tube. Remove purge solenoid and spark plug wires. Remove valve cover. Remove rocker arm bolts. If pushrods are to be replaced only, back off valve rocker arm bolts until valve rocker arm can be swung away from pushrod and remove pushrod.

Coat bearing surfaces with High Viscosity Oil/Zinc (GM P/N 12345501). Valve cover gaskets are reusable. Replace gaskets only if damaged. Tighten to specification. See TORQUE SPECIFICATIONS table. To install remaining components, reverse removal procedure.

1. Remove negative battery cable. If equipped, remove engine cover or floor pan. Remove upper fan shroud. Remove engine cooling fan. Remove accessory drive belt(s) and water pump pulley.
2. Raise and support vehicle. Remove lower fan shroud. Remove crankshaft balancer bolt. Remove crankshaft pulley bolts and crankshaft pulley.
3. Using Damper Puller/Installer (J-23523-F), remove crankshaft balancer. Carefully pry oil seal from front cover.

1. Coat crankshaft front cover oil seal lips with clean engine oil. Using Seal Installer (J-35468), install NEW seal in front cover with seal lip facing engine. Apply RTV sealant to Woodruff keyway in crankshaft balancer.
2. Using Damper Puller/Installer (J-23523-F), install crankshaft balancer. Tighten fasteners to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. To install remaining components, reverse removal procedure.

Note. DO NOT reinstall original composite front cover. Always install a NEW front cover. Reinstalling original front cover can lead to oil leaks.

1. Remove negative battery cable. If equipped, remove engine cover or floor pan. Remove upper fan shroud. Remove engine cooling fan. Remove accessory drive belt(s) and water pump pulley.
2. Raise and support vehicle. Remove lower fan shroud. Remove crankshaft balancer bolt. Remove crankshaft pulley bolts and crankshaft pulley.
3. Using Damper Puller/Installer (J-23523-F), remove crankshaft balancer. Remove water pump. See «WATER PUMP»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m__water-pump) .
4. Disconnect Crankshaft Position (CKP) sensor harness connector. Remove CKP sensor bolt and CKP sensor. Loosen or remove oil pan as necessary for removal of front cover.
5. Remove front cover bolts, front cover and gasket.

1. Install NEW front cover and gasket. Tighten front cover bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table.
2. Install CKP sensor. Tighten CKP sensor holddown bolt to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table.
3. Apply RTV sealant to Woodruff keyway in crankshaft balancer. Using Damper Puller/Installer (J-23523-F), install crankshaft balancer. Tighten fasteners to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. To install remaining components, reverse removal procedure.

1. Remove front cover. See «FRONT COVER»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m).
2. Remove Crankshaft Position (CKP) sensor reluctor ring. (Scheme 39) Rotate crankshaft until timing marks on camshaft and crankshaft sprockets are aligned. (Scheme 40) Remove camshaft sprocket and timing chain. To remove crankshaft sprocket, use Sprocket Puller (J-5825-A).

1. Install Woodruff key in crankshaft (if removed). Using Crankshaft Sprocket Installer (J-5590), install crankshaft sprocket. Install camshaft sprocket and timing chain. Ensure timing marks on sprockets are aligned. (Scheme 40)
2. Balance shaft drive gear, driven gear and gear bolt are serviced as a set. Install and tighten camshaft sprocket bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table.
3. Install and align CKP sensor reluctor ring. (Scheme 39) Install NEW front cover and gasket. Tighten front cover bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table.
4. Install CKP sensor. Tighten CKP sensor holddown bolt to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table.
5. Apply RTV sealant to Woodruff keyway in crankshaft balancer. Using Damper Puller/Installer (J-23523-F), install crankshaft balancer. Tighten fasteners to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. To install remaining components, reverse removal procedure.

Scheme 39

Scheme 40

ROCKER ARM STUDS

1. Rocker arm studs are pressed into cylinder head. Install Stud Remover (J-5802-01) over stud. Install flat washer and nut. Tighten nut to remove stud from cylinder head.
2. If stud is loose in cylinder head, ream stud bore for oversize stud using Reamer (J-5715). Ream stud bore for .003" (.08 mm) oversize stud or (J-6036) for .013" (.33 mm) oversize stud.
3. Coat press-fit area of stud with hypoid axle lubricant. Using Stud Driver (J-6880), drive stud into bore until driver bottoms against cylinder head.

Remove upper and lower intake manifold. See appropriate intake manifold section. Remove valve covers. Remove push rods. See ROCKER ARMS & PUSH RODS . Remove stuck valve lifter using Valve Lifter Remover (J-9290-01).

Coat lifter base or roller (if equipped) and body with High Viscosity Oil/Zinc (12345501) or equivalent. Install lifters in original location. To complete installation, reverse removal procedure. Replace oil and filter, and add High Viscosity Oil/Zinc (GM P/N 12345501) or equivalent.

1. Drain coolant and remove radiator. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment and remove A/C condenser (if equipped) and grille.
2. Remove timing chain and camshaft sprocket. See «TIMING CHAIN & SPROCKETS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) . Remove balance shaft gear (if equipped). Remove thrust plate. If necessary, raise engine. Remove camshaft.

Coat camshaft lobes and bearing journals with High Viscosity Oil/Zinc (12345501). Ensure bearing oil holes align with oil holes in block. On engines where oil holes are difficult to see, use a piece of 3/32" rod to check alignment. Install outer camshaft bearing first. Install camshaft. To complete installation, reverse removal procedure. Evacuate and recharge A/C system.

Remove transmission. On A/T, see TRANSMISSION REMOVAL & INSTALLATION article in TRANSMISSION SERVICING. On M/T see appropriate article in CLUTCH . Remove flywheel. Pry seal from housing.

1. Lubricate inner and outer diameter of seal with engine oil. Place seal on Seal Installer (J-35621). Position seal against crankshaft as indicated in illustration. (Scheme 41)
2. Thread attaching screws into crankshaft flange and tighten with screwdriver. This squares seal with crankshaft. Rotate seal installer handle until it bottoms. Remove seal installer. Install flywheel, clutch (M/T) and transmission.

Scheme 41

WATER PUMP

Note. DO NOT immerse water pump in solvent. Solvent may cause premature bearing failure.

Disconnect battery. Drain cooling system. Remove all drive belts, coolant hoses and mounting brackets attached to water pump. If necessary, remove fan shroud. Remove fan and pulley. Remove water pump and gaskets.

Install water pump with NEW gaskets. Tighten water pump bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure.

1. Disconnect battery. Raise and support vehicle. Drain crankcase. Remove exhaust crossover pipe, strut rods, strut rod brackets and flywheel cover.
2. Remove starter. Remove or disconnect engine oil cooler lines and/or transmission fluid lines as necessary. Remove oil pan bolts, oil pan and gasket.

Note. If transmission and oil pans are removed at same time. Transmission pan must be installed before oil pan.

1. Apply RTV sealant to front cover-to-cylinder block junction and rear main bearing-to-cylinder block junction.
2. Install oil pan. Tighten oil pan bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. To complete installation, reverse removal procedure. Fill crankcase.

Valve Springs

1. Measure valve spring free length, installed height and pressure (tension). Replace valve spring if measurement is not within specification. See «VALVES & VALVE SPRINGS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table under ENGINE SPECIFICATIONS.
2. Measure installed height between cylinder head spring seat (or top of shim, if shimmed) and top of spring shield. If installed height exceeds specification, install shims as necessary to bring installed height to specification.

Valve Stem Oil Seals

1. Intake and exhaust valves use upper "O" ring seal and lower umbrella seal.
2. When installing umbrella seal, seat seal against valve guide boss on cylinder head. If equipped, coat upper "O" ring seal with engine oil before installation and ensure seal is not twisted when installed. A gap of.040-.080" (1-2 mm) must exist between edge of oil seal and valve guide. (Scheme 42)

Valve Guides

Valve guides are part of cylinder head (not replaceable). Measure valve guide oil clearance. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. If not within specification, ream valve guide and install valves with oversize stems.

Valves

Replace valve if margin is less than .031" (.8 mm).

Scheme 42

Rocker Arm Assembly

Clean push rods, rocker arms, balls and nuts with solvent and blow dry. Inspect rocker arms and balls at mating surface. Surface should be smooth and free of damage. Inspect push rods for bends or wear. Ensure oil passages are clear.

Piston & Rod Assembly

1. Mark piston in relation to cylinder bore before removal. Piston pin is press-fit in connecting rod. Mark piston in relation to connecting rod before separating components.
2. Replace piston and piston pin as matched set. Install piston in bore with notch on top of piston toward front of engine.

Fitting Pistons

1. Measure piston diameter at 90-degree angle to piston pin, on piston pin center line. Measure cylinder bore diameter 2 1/2" below cylinder block deck. Determine piston clearance.
2. If piston clearance is not within specification, replace piston and/or machine cylinder bore as necessary. See «CYLINDER BLOCK»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) and «PISTONS, PINS & RINGS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) tables under ENGINE SPECIFICATIONS.

Piston Rings

Measure piston ring end gap and side clearance. If measurement is not within specification, replace piston and/or rings as necessary. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS. Install rings with mark on ring facing upward. Position ring end gaps around circumference of piston as shown. (Scheme 43)

Scheme 43

Rod Bearings

1. Measure rod bearing journal out-of-round, taper and oil clearance. If measurement is not within specification, replace rod bearings and/or machine crankshaft. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table under ENGINE SPECIFICATIONS.
2. Ensure rod side play is within specification. See «CONNECTING RODS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table under ENGINE SPECIFICATIONS.

Crankshaft & Main Bearings

1. Mark bearing caps for reassembly. Measure journal diameter, out-of-round, taper and oil clearance. If measurement is not within specification, replace main bearings and/or machine crankshaft. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table under ENGINE SPECIFICATIONS.
2. Align thrust bearing surfaces, and measure crankshaft end play. See «THRUST BEARING»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m__thrust-bearing) . Main bearing caps are press fit. Using Tool (J-6125-B and J-41348), carefully remove caps for service. Install main bearings and main caps. Tap bearing caps into cylinder block cavity using a brass, lead, or leather mallet before installing attaching bolts.
3. DO NOT use cap bolts to pull crankshaft bearing caps into seats. Tighten NEW main cap bolts evenly.

Thrust Bearing

1. Install main bearing caps (except rear), and tighten cap bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. Install rear main bearing cap and tighten cap bolts to 10 ft. lbs. (14 N.m).
2. Tap crankshaft rearward then forward to align thrust surfaces. Tighten rear main bearing cap bolts to specification. Measure crankshaft end play at forward thrust surface of rear main bearing cap. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table under ENGINE SPECIFICATIONS.

Cylinder Block

Measure cylinder bore out-of-round and taper. If measurement is not within specification, machine cylinder bore and/or replace piston. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS. Finish bore with a 45-65 degree cross-hatch pattern.

ENGINE LUBRICATION SYSTEM

Gear-type oil pump delivers full pressure lubrication through full-flow oil filter to main oil gallery. Main oil gallery feeds crankshaft and camshaft bearings through drilled passages in block.

Valve lifter oil gallery feeds valve lifters. From lifters, oil is routed through hollow push rods to upper valve train components. Timing chain and sprockets are lubricated by oil drainage from No. 1 camshaft bearing. Pistons and piston pins are lubricated by oil splash. Non-adjustable oil pressure regulator is located in oil pump body.

Crankcase Capacity

Crankcase capacity is 5.0 qts (4.7L), including oil filter.

Oil Pressure

Measure oil pressure with engine at operating temperature and specified RPM. See OIL PRESSURE SPECIFICATIONS table.

OIL PRESSURE SPECIFICATIONS (1)

Removal & Disassembly

Note. Pick-up tube is serviceable; however, unless tube is damaged, DO NOT remove tube from pump body.

1. Remove oil pan. See «OIL PAN»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) under REMOVAL & INSTALLATION. Remove oil pump bolt. Remove pump and extension shaft. If necessary, remove pick-up tube.
2. Remove pump cover. Mark relationship between gears at a meshing point for reassembly. Remove gears. Remove pressure regulator valve retaining pin. Remove pressure regulator valve and spring. Remove oil pump-to-rear crankshaft bearing cap bolt. Remove oil pump, retainer and driveshaft from rear crankshaft bearing cap.

Inspection

Inspect pump body and cover for cracks or excessive wear. Inspect pump gears for damage or wear. Check drive gear shaft for looseness in pump body. Check pressure regulator valve for fit in bore. Replace entire pump assembly if damaged. Inspect inlet tube and screen assembly for damage.

Reassembly & Installation

1. Install pump gears into pump body with marked gear teeth indexed. If pick-up tube was removed, apply sealant to tube end. Tap tube end into pump using plastic hammer. Reassemble remaining components in reverse order of disassembly.
2. Prime oil pump with engine oil. Install pump and extension shaft, ensuring slot on top of extension shaft engages with drive tang on end of distributor shaft. Tighten oil pump bolt to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g2500/1996-1998/remont/mechanical/#engine-mechanical-50l-v8-vin-m) table. Install oil pan.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL SPECIFICATIONS

GENERAL SPECIFICATIONS

CRANKSHAFT, MAIN BEARINGS & CONNECTING ROD BEARINGS SPECIFICATIONS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CONNECTING RODS SPECIFICATIONS

CONNECTING RODS

PISTONS, PISTON PINS & PISTON RINGS SPECIFICATIONS

PISTONS, PINS & RINGS

CYLINDER BLOCK SPECIFICATIONS

CYLINDER BLOCK

ENGINE VALVES & VALVE SPRINGS SPECIFICATIONS

VALVES & VALVE SPRINGS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD

CAMSHAFT SPECIFICATIONS

CAMSHAFT

See also:
• ENGINE IDENTIFICATION CODES
• FUEL PRESSURE RELEASE
• COOLING SYSTEM BLEEDING
• POWER STEERING BLEEDING
• SHIFT CABLE ADJUSTMENT
• VALVE CLEARANCE ADJUSTMENT
• WATER PUMP
• THRUST BEARING