Engine Mechanical - 3.1l v6 - VIN [M] Chevrolet Malibu V

VEHICLE IDENTIFICATION NUMBER (VIN)

VIN is stamped on a metal tab, which is attached to top left end of instrument panel, near windshield. If eighth character of VIN is "M", vehicle is factory-equipped with a 3.1L V6 SFI engine. If tenth character of VIN is "W", vehicle is a 1998 model year. If tenth character of VIN is "X", vehicle is a 1999 model year.

ENGINE CODE & PARTIAL VIN

An engine code (3 characters) and a partial VIN (9 characters) are stamped on cylinder block, in one of the following places

1. Top of cylinder block, above front cover.
2. On cylinder block flange, where engine mates to transaxle (may be on either side of engine).

Engine code L82 identifies 3.1L V6 SFI engine.

VALVE CLEARANCE (LASH) ADJUSTMENT

Valve rocker arms are mounted to cylinder head by non-adjustable pedestals and bolts. Although valve lash is not adjustable, if cylinder head has been resurfaced or valves and seats reground, rocker arm pedestals may be shimmed to compensate. No further information is available from manufacturer.

TROUBLE SHOOTING

Note. To trouble shoot mechanical engine components, see ENGINE MECHANICAL in BASIC 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 negative battery cable. Loosen fuel tank filler cap. Connect Fuel Pressure Gauge (J-34730-1) to fuel line fitting (wrap shop towel around fitting to absorb leakage). Place gauge bleed hose into container. Open bleed valve to release pressure.

COOLING SYSTEM BLEEDING

Fill radiator and coolant reservoir. Leave radiator cap and coolant reservoir cap off. Open the coolant air bleed valve. The coolant air bleed valve (if equipped) is located on the top of the thermostat bypass pipe/heater pipe assembly. Close the valve once a continuous stream of coolant is expelled from the valve. Run engine until upper radiator hose starts to become hot. Ensure radiator is full. Install and tighten radiator cap and coolant reservoir cap.

Note. After servicing the cooling system, and if the vehicle is equipped with an intermittent low coolant light, an occasional low coolant light may be encountered during some extreme driving maneuvers. This complaint should be eliminated by removing the surge tank cap and adding coolant to a level just at or above the full cold line when the system is cold.

DRIVE BELT

Note. Removal and installation procedure given on these vehicles only due to the complicated procedure involved.

Removal (Cutlass & Malibu Only (3.1L & 3.4L))

Note. Tools Required: J-39914 Drive Belt Tension Wrench.

1. Disconnect the negative battery cable. Using the J-39914, rotate the belt tensioner. (Scheme 30)
2. Remove the drive belt from the generator pulley. Support the engine by the oil pan.
3. Remove the engine mount assembly from the engine mount bracket support. (Scheme 31) Remove the auxiliary bracket.
4. Lower the engine in order to remove the drive belt. (Scheme 32) Remove the drive belt.

Installation (Cutlass & Malibu Only (3.1L & 3.4L))

1. Using the J-39914, rotate the belt tensioner and install the drive belt.
2. Install the auxiliary bracket. Install the auxiliary bracket fasteners. Tighten the fasteners to 37 ft. lbs. (50 N.m).
3. Install the engine mount assembly to the engine mount bracket support bolts.
4. Remove the floor jack. Connect the negative battery cable.

Scheme 30

Scheme 31

Scheme 32

Note. Remove engine and transaxle as an assembly through bottom of engine compartment.

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__fuel-pressure-release) . Remove top half of air cleaner assembly. Remove throttle body duct. Drain cooling system. Disconnect control cables, coolant hoses, electrical connectors, vacuum hoses, and fuel lines as necessary.
2. Remove serpentine drive belt. Remove generator. Disconnect power steering lines from pump. Remove radiator fan. Remove vent tube from transaxle. Support engine from above with Engine Support Fixture (J-28467) and Adapter Leg (J-36462). Loosen, but DO NOT remove, top 2 A/C compressor bolts. Raise and support vehicle. Remove front wheels.
3. Remove left and right splash shields. At timing chain end of engine, remove engine mount strut near crankshaft balancer. Disconnect electrical connectors from ABS wheel speed sensors (if equipped) and suspension supports.
4. Separate ball joint studs from steering knuckles. Remove stabilizer shaft from control arms and suspension supports. Remove bolts securing left suspension support to body. Lower the suspension support and control arm as an assembly. Use same procedure to remove right suspension support and control arm assembly.
5. Disengage drive axles from transaxle, then support them with wire. See appropriate FWD AXLE SHAFTS article in DRIVE AXLES. Remove oil filter and adapter. Remove torque converter cover (A/T) or flywheel access cover (M/T). Remove starter.
6. Remove A/C compressor (leave hoses connected). Disconnect exhaust pipe from manifold. Remove engine mount strut bracket from engine (near crankshaft balancer). On A/T models, disconnect transaxle cooler lines from radiator. Remove transaxle dipstick tube.
7. On all models, put a suitable support table (such as a heavy table on rollers) under engine and transaxle assembly. Lower vehicle until engine and transaxle assembly just begins to rest on table. Remove remaining engine and transaxle mounts. Raise vehicle, leaving engine and transaxle assembly on table. Separate engine from transaxle. To install, reverse removal procedure. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__cooling-system-bleeding) .

Removal

See INTAKE MANIFOLD (LOWER) .

Installation

Clean gasket surfaces. Install NEW gaskets onto cylinder heads. Ensure all holes are aligned. For correct installation, observe reference marks on gaskets (if present). Install upper intake manifold. (Scheme 33) Using crisscross pattern, tighten bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. Fill and bleed cooling system if it was drained. See COOLING SYSTEM BLEEDING.

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__fuel-pressure-release). Remove top half of air cleaner assembly. Remove throttle body duct. Drain cooling system. Disconnect EGR pipe from exhaust manifold. Remove serpentine drive belt.
2. Disconnect power brake vacuum hose from manifold. Disengage power steering lines from retainers at generator bracket. Remove generator. Disconnect spark plug wires. Remove ignition coil pack and EVAP solenoid as an assembly. Disconnect vacuum lines, coolant hoses and electrical connectors as necessary.
3. Remove MAP sensor. Remove bolts securing upper intake manifold to lower intake manifold. Remove upper intake manifold and throttle body as an assembly. Disconnect fuel lines from fuel rail. Support engine from above with Engine Support Fixture (J-28467-A) and Adapter Leg (J-36462). Remove engine mount assembly. Remove power steering pump (leave hoses connected).
4. Remove coolant outlet housing. Remove rocker arm covers. Remove bolts securing lower intake manifold to cylinder heads. (Scheme 33) Remove lower intake manifold. If necessary, loosen rocker arms and remove push rods to remove gaskets.

1. Clean all gasket mating surfaces. Install lower intake manifold gaskets. Ensure all holes are aligned. For correct installation, observe reference marks on gaskets (if present).
2. With the gaskets in place, apply a 0.31-0.39" (8-10 mm) drop of GM® RTV sealer (12346286 US; 10953472 Canada) or equivalent to the 4 corners of the intake manifold-to-block joint. (Scheme 33) Connect the drops at both ends on the ridge where the front and rear of lower intake manifold contacts the block with a bead of RTV sealer that is 0.31-0.39" (8-10 mm) wide and 0.12-0.20" (3.0-5.0 mm) thick.
3. Intake push rods (marked Orange) are shorter than exhaust push rods (marked Blue). Install push rods and rocker arms in original locations. If applicable, adjust valve lash. See «VALVE CLEARANCE (LASH) ADJUSTMENT»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__valve-clearance-lash-adjustment) under ADJUSTMENTS. Install lower intake manifold.
4. Tighten lower intake manifold vertical bolts in sequence to specification, then tighten lower intake manifold diagonal bolts in sequence to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) table. (Scheme 34)
5. To complete installation, reverse removal procedure. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__cooling-system-bleeding).

Scheme 33

Scheme 34

1. Disconnect negative battery cable. Remove top half of air cleaner assembly. Remove throttle body duct. Partially drain cooling system. Disconnect upper radiator hose from thermostat housing. Disconnect coolant by-pass pipe from water pump and exhaust manifold.
2. Remove heat shield from exhaust crossover pipe. Disconnect exhaust crossover pipe from manifold. Disconnect spark plug wires. Remove heat shield, nuts and exhaust manifold.

Reverse removal procedure using NEW gasket. Tighten exhaust manifold fasteners to specification. See TORQUE SPECIFICATIONS table. Fill and bleed cooling system. See COOLING SYSTEM BLEEDING .

1. Disconnect negative battery cable. Remove top half of air cleaner assembly. Remove throttle body duct. Remove heat shield from exhaust crossover pipe. Disconnect exhaust crossover pipe from manifold. Remove oxygen sensor. Disconnect EGR pipe from manifold.
2. Raise and support vehicle. Remove transaxle oil fill tube (A/T). Disconnect exhaust downpipe from manifold. Disconnect exhaust pipe from catalytic converter flange. Support catalytic converter. Remove torque converter heat shield from body. Remove heat shield and exhaust manifold nuts. Remove exhaust manifold through bottom of engine compartment.

Reverse removal procedure using NEW gasket. Tighten exhaust manifold fasteners to specification. See TORQUE SPECIFICATIONS table. Fill and bleed cooling system. See COOLING SYSTEM BLEEDING .

Removal (Left)

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__fuel-pressure-release) . Drain cooling system. Remove lower intake manifold. See «INTAKE MANIFOLD (LOWER)»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) . Remove exhaust crossover pipe.
2. Remove rocker arm covers. Remove rocker arm nuts, rocker arms, and push rods. Remove oil dipstick tube. Remove cylinder head bolts, cylinder head and gasket.

Removal (Right)

Disconnect negative battery cable. Release fuel system pressure. See FUEL PRESSURE RELEASE . Drain cooling system. Remove lower intake manifold. See INTAKE MANIFOLD (LOWER) . Remove exhaust crossover pipe. Remove rocker arm covers. Remove rocker arm nuts, rocker arms, and push rods. Remove cylinder head bolts, cylinder head and gasket.

Inspection (Left & Right)

If warpage ofValve rocker arms are mounted to cylinder head by non-adjustable bolts. Although valve lash is not adjustable, if cylinder head has been resurfaced, rocker arm pedestals may be shimmed to compensate. No further information is available from manufacturer. If cylinder head gasket surface exceeds specification, machine surface. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. DO NOT remove more than .010" (.25 mm) of material from original surface.

Installation (Left & Right)

1. Clean cylinder head bolt threads and cylinder block holes. Install gasket on cylinder block with THIS SIDE UP mark up (if equipped). Ensure all holes align with cylinder block. Install cylinder head. Apply GM Sealant (1052080) to head bolt threads.
2. Tighten cylinder head bolts to specification in sequence. See «TORQUE SPECIFICATIONS»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m). (Scheme 35) To complete installation, reverse removal procedure. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__cooling-system-bleeding).

Scheme 35

1. Disconnect negative battery cable. Drain cooling system. Support engine from above with Engine Support Fixture (J-28467) and Adapter Leg (J-36462). Remove engine mount assembly. Remove engine mount bracket support. Remove serpentine drive belt.
2. Remove power steering pump (leave hoses connected). Loosen top 2 A/C compressor bolts. Raise and support vehicle. Remove right front wheel and inner splash shield. Remove flexplate/flywheel cover. Remove bolt and washer securing crankshaft balancer. Use a puller to remove crankshaft balancer.
3. Remove serpentine drive belt tensioner. Remove engine mount strut between top of radiator panel and left side of engine. Disconnect electrical connectors from ABS front wheel speed sensors (if equipped) and suspension supports. Separate right ball joint stud from steering knuckle. Disconnect stabilizer shaft from right control arm and right suspension support. Remove bolts, then remove right suspension support and control arm as an assembly.
4. Remove bolts securing A/C compressor to oil pan. Remove oil filter and adapter. Remove engine mount strut bracket. Remove brace between engine and transaxle. Drain crankcase. Remove starter. Remove oil pan. See «OIL PAN»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) . Remove crankshaft sensor. Remove lower bolts from front cover. Lower vehicle. Remove coolant by-pass pipe. Disconnect radiator hose from coolant outlet housing. Remove upper bolts and front cover. Remove oil seal from front cover.

1. Apply RTV sealant to sealing surface of front cover. Install NEW front cover oil seal. See «FRONT COVER OIL SEAL»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) . Apply RTV sealant to keyway in crankshaft and crankshaft damper.
2. Install crankshaft damper using Damper Installer (J-29113). Ensure damper installer threads are inserted at least .20" (5.1 mm) into crankshaft. To complete installation, reverse removal procedure.

Remove serpentine drive belt. Raise and support vehicle. Remove right front wheel and inner fender splash shield. Remove flexplate/flywheel cover. Prevent crankshaft from turning, and remove crankshaft balancer bolt. Remove crankshaft balancer with a puller. Remove crankshaft balancer key. Pry seal out of front cover with a large screwdriver.

Lubricate seal with engine oil. Using Seal Installer (J-35468), install seal with open end toward engine. To complete installation, reverse removal procedure.

Note. If camshaft sprocket does not come off easily, lightly strike lower edge of sprocket with a plastic mallet.

Rotate crankshaft until cylinder No. 1 is at TDC of compression stroke (align timing mark on crankshaft balancer with mark on front cover). Disconnect negative battery cable. Remove front cover. See FRONT COVER . Remove camshaft sprocket bolt. Remove camshaft sprocket and timing chain. Remove crankshaft sprocket with Crankshaft Sprocket Remover (J-5825-A).

1. Install crankshaft sprocket (if removed) using Installer (J-38612). If camshaft or crankshaft was rotated during removal of chain or sprockets, rotate camshaft and/or crankshaft as necessary to align timing marks. (Scheme 36)
2. Install timing chain onto camshaft sprocket. Hold camshaft sprocket vertically with chain hanging down. Install timing chain onto crankshaft sprocket, then camshaft sprocket onto camshaft. Install and tighten camshaft sprocket bolt to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) table. Lubricate timing chain with engine oil. To complete installation, reverse removal procedure.

Scheme 36

Disconnect negative battery cable. Remove lower intake manifold. See INTAKE MANIFOLD (LOWER) . Remove rocker arms and push rods. Remove bolts and lifter guide. Remove lifters. Mark component locations for installation reference.

If installing old lifters, lubricate lifters and bores with engine oil. If replacing lifters, lubricate lifter and bores with Prelube (1052365). Install lifters. To complete installation, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS table.

1. Disconnect negative battery cable. Remove engine. See «ENGINE»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) . Remove lower intake manifold. See «INTAKE MANIFOLD (LOWER)»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) . Remove rocker arms and push rods. Remove bolts and lifter guide. Remove lifters. Mark component locations for installation reference. Remove front cover. See «FRONT COVER»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) .
2. Remove timing chain and camshaft sprocket. See «TIMING CHAIN»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) . Remove oil pump drive assembly from top rear of cylinder block (held in place with a bolt and clamp like a distributor). Remove camshaft thrust plate. Remove camshaft. If necessary, remove camshaft bearings using Remover/Installer (J-33049).

Inspection

If journal runout, lobe lift or oil clearance is not within specification, replace camshaft. See CAMSHAFT table under ENGINE SPECIFICATIONS.

Lubricate camshaft bearings and lobes with engine oil. Install camshaft. To complete installation, reverse removal procedure. Ensure timing marks are aligned. (Scheme 36) Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS table.

1. Disconnect negative battery cable. Remove transmission. See appropriate REMOVAL & INSTALLATION - A/T article in TRANSMISSION SERVICING.
2. On M/T models, mark clutch pressure plate and flywheel for installation reference. Remove pressure plate, clutch disc and flywheel. On A/T models, remove flexplate and retainer.
3. On all models, careful pry seal from housing (DO NOT damage sealing surfaces). Note direction of seal installation.

1. Coat inner and outer seal surfaces with engine oil. Install seal on mandrel of Seal Installer (J-34686) until dust lip bottoms against seal installer collar. (Scheme 37)
2. Install seal installer onto crankshaft, aligning dowel pin on seal installer with alignment hole in crankshaft flange. To install seal in seal bore, tighten seal installer handle until collar on seal installer is even with cylinder block.
3. To complete installation, reverse removal procedure. Align reference marks on pressure plate and flywheel (M/T models). Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) table.

Scheme 37

RADIATOR (ACHIEVA, GRAND AM & SKYLARK - 1998)

Note. When adding coolant, it is important that you use GM Goodwrench DEX-COOL™ coolant. If coolant other than DEX-COOL™ is added to the system, the engine coolant will require change sooner: at 30,000 miles (50 000 km) or 24 months.

1. Disconnect the negative battery cable
2. Drain the cooling system. Recover the coolant.
3. Remove the air intake duct assembly by removing the air cleaner outlet resonator mounting screws. Disconnect the air cleaner outlet resonator clamp at throttle body. Remove the air cleaner outlet duct from air cleaner outlet resonator and air cleaner assembly. Disconnect the crankcase vent hose from the air cleaner outlet resonator. Remove the air cleaner outlet resonator.
4. Disconnect the upper transaxle oil cooler line from the radiator (Automatic Transmission).
5. Disconnect the radiator inlet hose and the clamp from the radiator
6. Raise the vehicle. See «JACKING & HOISTING»(/chevrolet/malibu/v-1996-2000/remont/wheel-alignment/#wheel-alignment-specifications-adjustment-procedures) in SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.
7. Disconnect the lower transaxle oil cooler line from the radiator.
8. Remove the cooling fan by removing the cooling fan bracket bolt. Disconnect the wiring harness connector from the fan motor. Remove the cooling fan assembly.
9. Remove the splash shield that is below the radiator outlet hose.
10. Disconnect the radiator outlet hose from the radiator.
11. Lower the vehicle.
12. Remove the retaining clip from the condenser line
13. Remove the condenser to radiator bolts.
14. Disconnect the surge tank inlet hose and the clamp from the radiator.
15. Remove the radiator retaining bolts and the mounts.
16. Remove the radiator.

1. Install the radiator
2. Install the radiator mounts and the bolts Tighten the bolts to 89 INCH lbs. (10 N.m).
3. Connect the surge tank inlet hose and the clamp to the radiator
4. Install the radiator to condenser bolts. Install the retaining clip to the condenser line.
5. Raise the vehicle.
6. Connect the radiator outlet hose and the clamp to the radiator.
7. Install the splash shield that is below the radiator outlet hose.
8. Install the cooling fan.
9. Connect the lower transaxle oil cooler line to the radiator (Automatic Transmission). Tighten the transaxle oil cooler line fitting to 22 ft. lbs. (30 N.m).
10. Lower the vehicle.
11. Connect the radiator inlet hose and the clamp to the radiator.
12. Connect the upper transaxle oil cooler line to the radiator (Automatic Transmission). Tighten the transaxle oil cooler line fitting to 22 ft. lbs. (30 N.m).
13. Connect the air intake duct assembly.
14. Fill the cooling system. Bleed cooling system and check for leaks. See «COOLING SYSTEM BLEEDING»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__cooling-system-bleeding) . NOTE: After servicing the cooling system, an intermittent low coolant lamp may illuminate during extreme driving maneuvers. In order to eliminate this condition, remove the surge tank cap and add coolant to a level at or above the split line of the tank when the system is cold.

Note. When adding coolant, it is important that you use GM Goodwrench DEX-COOL™ coolant. If coolant other than DEX-COOL™ is added to the system, the engine coolant will require change sooner: at 30,000 miles (50 000 km) or 24 months.

1. Remove the negative battery cable.
2. Evacuate and recover the A/C system refrigerant. See «A/C SYSTEM GENERAL SERVICING»(/chevrolet/malibu/v-1996-2000/remont/general-servicing-all-makes/#hvac-system-general-servicing) article in HEATING & AIR CONDITIONING.
3. Drain the cooling system.
4. Remove the upper radiator hose.
5. Remove the upper transaxle cooler line.
6. Remove the coolant surge tank hose.
7. Remove the condenser inlet fitting from discharge hose.
8. Remove the lower transaxle cooler line.
9. Disconnect the cooling fan electrical connection.
10. Raise and suitably support the vehicle. See «JACKING & HOISTING»(/chevrolet/malibu/v-1996-2000/remont/wheel-alignment/#wheel-alignment-specifications-adjustment-procedures) in SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.
11. Remove the lower closeout panel.
12. Remove the lower radiator hose from the radiator.
13. Remove the evaporator line from the condenser outlet.
14. Remove the Lower Radiator Mounting Panel.
15. Remove the CRFM from the vehicle.
16. Remove the condenser from the radiator.
17. Remove the fan shroud from the radiator.

1. Install the fan shroud to the radiator
2. Install the condenser to the radiator. Tighten the bolt to 44 INCH lbs. (5 N.m).
3. Install the CRFM to the vehicle.
4. Install the lower radiator mounting panel. Tighten the bolts to 89 INCH lbs. (10 N.m).
5. Install the condenser outlet to the evaporator line. Tighten the bolt to 18 ft. lbs. (25 N.m).
6. Install the lower radiator hose to the radiator.
7. Install the lower closeout panel.
8. Lower the vehicle. Install the cooling fan electrical connection.
9. Install the lower transaxle cooler line. Tighten the bolt to 22 ft. lbs. (30 N.m).
10. Install the condenser inlet fitting to the discharge hose. Tighten the bolt to 18 ft. lbs. (25 N.m).
11. Install the coolant surge tank hose.
12. Install the upper transaxle cooler line. Tighten the bolt to 22 ft. lbs. (30 N.m).
13. Install the upper radiator hose.
14. Connect the negative battery cable. Tighten the bolt to 12 ft. lbs. (16 N.m).
15. Refill the cooling system.
16. Recharge the A/C system. See «CHARGING A/C SYSTEM»(/chevrolet/malibu/v-1996-2000/remont/general-servicing-all-makes/#hvac-system-general-servicing__charging-ac-system) in A/C SYSTEM GENERAL SERVICING article in HEATING & AIR CONDITIONING.
17. Bleed cooling system if necessary. See «COOLING SYSTEM BLEEDING»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__cooling-system-bleeding) . Inspect for leaks.

Note. After servicing the cooling system, and if the vehicle is equipped with an intermittent low coolant light, an occasional low coolant light may be encountered during some extreme driving maneuvers. This complaint should be eliminated by removing the surge tank cap and adding coolant to a level just at or above the full cold line when the system is cold.

1. Drain the cooling system.
2. Remove the air cleaner.
3. Remove exhaust crossover pipe.
4. Disconnect the surge tank line fitting from the coolant outlet.
5. Remove the thermostat housing to intake manifold bolts. (Scheme 38)
6. Remove the thermostat housing outlet and thermostat.

Scheme 38

1. Install the thermostat and housing outlet. NOTE: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
2. Install the thermostat housing bolts. (Scheme 38) Tighten: Tighten the thermostat housing bolts to 25 N.m (18 lb ft).
3. Install exhaust crossover pipe.
4. Connect the surge tank line fitting to the coolant outlet. Tighten: Tighten the surge tank line fitting to 21 N.m (15 lb ft).
5. Install the air cleaner.
6. Fill the cooling system. Refer to «COOLING SYSTEM BLEEDING»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m__cooling-system-bleeding).
7. Inspect the system for leaks.

Disconnect negative battery cable. Drain cooling system. Remove air cleaner (if necessary). Loosen water pump pulley bolts. Remove serpentine drive belt. Remove water pump pulley bolts and pulley. Note position of locator tab on top of water pump for installation reference. Remove bolts, water pump and gasket.

Apply thread sealant to water pump bolts. Install water pump and NEW gasket. Ensure locator tab on top of water pump housing is positioned vertically. Tighten bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. Fill and bleed cooling system. See COOLING SYSTEM BLEEDING .

1. Disconnect negative battery cable. Remove serpentine drive belt. Loosen, but DO NOT remove, A/C compressor upper bolts. Raise and support vehicle. Drain crankcase. Remove right front wheel and inner splash shield. Remove engine mount strut near crankshaft balancer. Disconnect ABS wheel speed sensor connector.
2. Separate right ball joint stud from steering knuckle. Disconnect stabilizer shaft link from right control arm and suspension support. Put an adjustable floor stand under right suspension support. Remove bolts securing right suspension support to body. Lower right suspension support and control arm as an assembly.
3. Remove A/C compressor lower bolts, and position A/C compressor aside with hoses attached. Remove engine mount strut bracket. Remove brace between engine and transaxle. Remove oil filter, starter, and flexplate/flywheel cover. Remove oil pan side bolts, oil pan bottom bolts, and oil pan.

Clean gasket surfaces of oil pan and cylinder block. Apply RTV sealant to tab grooves in rear main bearing. Install oil pan and NEW gasket. Tighten oil pan bottom bolts to specification, then tighten oil pan side bolts. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. Fill crankcase.

Gasket Surface

If warpage of gasket surface exceeds specification, machine cylinder head. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. DO NOT remove more than .010" (.25 mm) of material from original surface of cylinder head.

Valve Springs

Replace spring if free length, out-of-square, pressure or installed height is not as specified. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS.

Valve Stem Oil Seals

If oversize valves are installed, use oversize seals. Ensure seal is fully seated on guide. Intake and exhaust seals are different.

Valve Guides

If valve stem-to-guide oil clearance is not within specification, ream valve guide and install oversize valve. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. DO NOT knurl valve guides.

Valve Seats

If valve seat width or runout is not within specification, machine or replace valve seat as necessary. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. Valve seat replacement procedure is not available from manufacturer.

Valves

If valve margin is not within specification, replace valve. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS.

Valve Seat Correction Angles

If seat contact is too low (too close to stem) or too wide, use a 70-degree stone to raise or narrow seat.

Piston & Rod Assembly

Mark piston with cylinder number for installation in original location. Replace rod if bend or twist exceeds specification. See CONNECTING RODS table under ENGINE SPECIFICATIONS. Install piston with arrow on top of piston toward front of engine.

Fitting Pistons

1. Measure cylinder bore diameter at top and center of bore. Measure piston diameter at 90-degree angle to piston pin bore, 1/4" below center line of piston pin bore.
2. If piston clearance is not within specification, machine cylinder bore and install oversize piston as necessary. See «PISTONS, PINS & RINGS»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) table under ENGINE SPECIFICATIONS. DO NOT machine oversize piston to fit cylinder bore, or engine balance will be affected.

Piston Rings

If piston ring end gap or side clearance is not within specification, replace piston rings and/or piston as necessary. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS. Install piston rings with identification mark on ring land facing top of piston. Properly position end gaps of piston rings around circumference of piston. (Scheme 39)

Rod Bearings

If rod bearing oil clearance is not within specification, machine crankshaft and replace bearings. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS.

Crankshaft & Main Bearings

Measure crankshaft main bearing oil clearance, out-of-round and taper. If measurements are not within specification, machine crankshaft and replace bearings. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS.

Thrust Bearing

Measure crankshaft end play (thrust bearing clearance). See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS. If not within specification, replace bearing and/or repair or replace crankshaft.

Cylinder Block Deck Surface

If deck surface warpage exceeds specification, machine surface. DO NOT remove more than .010" (.25 mm) of material from original deck surface.

Valve Lifter Bores

Oversize valve lifters are available. If oversize lifters are installed, stamp oversize on cylinder block near lifter bore to indicate oversize lifters have been installed.

Scheme 39

ENGINE LUBRICATION SYSTEM

A camshaft-driven, gear-type oil pump provides pressurized lubrication through oil filter to main gallery above left side of camshaft center line. (Scheme 40) This gallery provides lubrication to valve lifters on left bank, camshaft bearings, crankshaft and right gallery.

Right gallery supplies oil to valve lifters on right bank. Rocker arms are lubricated by passages in push rods. Slot in front camshaft bearing provides lubrication to camshaft sprocket thrust face. Pressure regulator valve is mounted in oil pump body.

Crankcase Capacity

Engine oil capacity is about 4 qts. (3.8L) without filter change. More oil may be necessary when replacing oil filter.

Oil Pressure

Minimum allowable oil pressure is 15 psi (1 kg/cm 2 ) at 1100 RPM.

Scheme 40

Removal & Disassembly

1. Remove oil pan. See «OIL PAN»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) under REMOVAL & INSTALLATION. Remove oil pump bolt, oil pump and extension shaft from rear main bearing cap.
2. To disassemble, remove pump cover. DO NOT remove pick-up tube from cover unless loose or broken. If pick-up tube is loose, bent or has been removed, replace pick-up tube and pump cover.
3. Remove gears from pump body. Remove cotter pin securing spring and pressure regulator valve. Remove valve and spring.

1. Inspect components for damage. Using straightedge and feeler gauge, measure gear end clearance. Measure housing pocket depth and diameter. Measure gear diameter and length (thickness). Measure side clearance between gear tooth and housing.
2. Measure gear lash clearance between gear teeth. Check clearance between pressure regulator valve and bore. Replace components or entire assembly if not within specification. See «OIL PUMP SPECIFICATIONS»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) table.

OIL PUMP SPECIFICATIONS

Reassembly & Installation

Note. Use only original equipment gaskets for oil pump service, as gasket thickness is critical.

1. Coat all components with engine oil. To reassemble, reverse disassembly procedure using NEW pump cover gasket. If installing new pick-up tube, apply Sealant (1050026) to pick-up tube. Install pick-up tube into pump cover using Suction Pipe Installer (J-21882) and plastic hammer.
2. To install, reverse removal procedure. Ensure pump extension shaft is fully engaged. Tighten oil pump bolt to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/malibu/v-1996-2000/remont/mechanical/#engine-mechanical-31l-v6-vin-m) table.

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

CAMSHAFT SPECIFICATIONS

CAMSHAFT

ENGINE VALVES & VALVE SPRINGS SPECIFICATIONS

VALVES & VALVE SPRINGS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD

See also:
• ENGINE MECHANICAL
• COMPUTER RELEARN PROCEDURES
• JACKING & HOISTING
• A/C SYSTEM GENERAL SERVICING
• CHARGING A/C SYSTEM
• FUEL PRESSURE RELEASE
• COOLING SYSTEM BLEEDING
• INTAKE MANIFOLD (LOWER)
• VALVE CLEARANCE (LASH) ADJUSTMENT