5.7L v8 - VIN [8] Chevrolet Corvette C4

ENGINE IDENTIFICATION

Note. For engine repair procedures not covered in this article, see ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article in the GENERAL INFORMATION section.

Engine may be identified using Vehicle Identification Number (VIN) stamped on a metal pad, located near lower left corner of windshield. The eighth character identifies the engine model. See ENGINE IDENTIFICATION CODES table.

Engine identification code, located on cylinder block below cylinder head, may be required when ordering replacement parts. See ENGINE IDENTIFICATION CODES .

ENGINE IDENTIFICATION CODES

VALVE ARRANGEMENT

E-I-I-E-E-I-I-E (Front-to-rear, both banks).

VALVE CLEARANCE ADJUSTMENT

Note. Hydraulic valve lifters are used. Under normal use, no valve adjustment is required.

1. Place number one cylinder on TDC of compression stroke. Ensure timing mark on damper and front cover are aligned. Refer to «VALVE ADJUSTMENT SEQUENCE»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8) . Back off adjusting nut until lash is felt at pushrod. Rotate pushrod while tightening adjusting nut until lash is removed. With lash removed, tighten adjusting nut 3/4 to 1 1/4 additional turn.
2. Rotate crankshaft one revolution and align timing marks. No. 6 cylinder will be on TDC. Adjust remaining valves in same manner.

VALVE ADJUSTMENT SEQUENCE

TROUBLE SHOOTING

Note. To trouble shoot engine mechanical 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

Loosen fuel tank filler cap. Connect Fuel Gauge (J-34730-1) to fuel pressure connection mounted on fuel rail, on right side of fuel pressure regulator. Wrap shop towel around fitting during installation to avoid spillage. Install bleed hose. Turn gauge valve and drain fuel into an appropriate container.

COOLING SYSTEM BLEEDING

1. With engine off, fill radiator until level is even with base of filler neck. Fill coolant recovery reservoir to COLD mark. Add coolant to high-fill reservoir until level is at base of filler neck.
2. Install coolant recovery reservoir cap. Run engine until radiator inlet hose is hot. Add coolant to high-fill reservoir to maintain level at base of filler neck. Install cap. Fill coolant recovery reservoir to HOT mark.

Removal

1. Release fuel pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__fuel-pressure-release) . Drain coolant from radiator. Remove air cleaner and serpentine belt. Remove brackets at back of A/C compressor. Disconnect wires at the A/C compressor.
2. Remove plenum extension (if equipped). Disconnect and cap fuel lines at front fuel hose-to-fuel line connections. Remove A/C compressor mounting bracket nuts and bolts. Disconnect heater hoses. Disconnect upper radiator hose at thermostat outlet.
3. Remove A/C compressor-to-mounting bracket bolt and move compressor aside. Remove mounting bracket. Disconnect Port Fuel Injection (PFI) harness at engine. Disconnect cruise, detent and accelerator cables.
4. Label and remove spark plug wires from spark plugs. Remove distributor cap and spark plug wires as an assembly. Mark position of distributor for installation reference. Remove distributor assembly. Disconnect detent cable bracket at intake. Remove cowl screen. Remove nut from wiper motor and remove wiper motor. Disconnect wires at oil pressure sending unit. Disconnect vacuum hoses.
5. Remove power steering pump, and wire aside. Remove crankshaft pulley. Disconnect bulkhead connector and necessary connectors. Disconnect Air Injection Reaction (AIR) hose at converter check valve. Move fuel lines aside.
6. Disconnect radiator hose at water pump. Disconnect upper radiator hose at power steering reservoir bracket. Raise and support vehicle. Drain engine oil and remove oil filter. Remove oil cooler adapter at engine. Disconnect AIR pipe at exhaust manifold. Remove AIR converter pipe.
7. Disconnect "Y" pipe hanger. Disconnect heat shields at "Y" pipe and converter. Disconnect oxygen sensor wire. Remove "Y" pipe. Remove flexplate/flywheel cover.
8. On A/T models, remove torque converter bolts. On all models, remove transmission-to-bellhousing bolts.
9. Loosen motor mount through bolts. Remove motor mount-to-engine block bolts. Disconnect knock sensor wire. Disconnect ground cable at engine. Disconnect positive battery cable at battery and harness.
10. Lower vehicle. Support transmission with floor jack. Install engine lift. Carefully lift engine out of vehicle, disconnecting wire from bracket at left rear of engine.

Installation

To install, reverse removal procedure. Tighten fasteners to specification. See TORQUE SPECIFICATIONS . Fill and bleed cooling system. See COOLING SYSTEM BLEEDING .

1. Disconnect negative battery cable and drain cooling system. Relieve fuel pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__fuel-pressure-release). Remove air intake duct assembly. Disconnect accelerator, throttle valve and cruise control cables (if equipped). Mark and disconnect necessary electrical connectors and vacuum hoses.
2. Remove heater hoses. Remove bolts attaching left runners to upper and lower intake manifold. (Scheme 1) Remove PCV valve and hose. Remove bolts attaching right runners to upper and lower intake manifold. Remove EGR valve, pipe and solenoid.
3. Remove lower manifold-to-runner bolts on each side. Right-side bolt is located near engine front, and left-side bolt is located near rear of engine. Remove upper intake manifold and runners. Remove and discard gaskets.
4. Disconnect injector harness and fuel lines. Remove fuel rail and injectors as an assembly. Mark and remove spark plug wires at distributor. Mark position of distributor for installation reference. Remove distributor assembly. Disconnect necessary cooling system hoses. Remove lower intake manifold bolts. Remove lower intake manifold and gaskets.

1. Clean all gasket surfaces. Apply 3/16" bead of RTV Sealer (1052289) on front and rear of cylinder block, and apply 1/2" onto each cylinder head. Install NEW gaskets. Install lower intake manifold.
2. Apply Loctite (1052624) to lower intake manifold bolts. Tighten bolts to specifications in sequence. (Scheme 1) See «TORQUE SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__torque-specifications). To complete installation, reverse removal procedure. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__cooling-system-bleeding).

Scheme 1

EXHAUST MANIFOLD

1. Disconnect negative battery cable. Remove air cleaner as necessary. Remove Air Injection Reaction (AIR) hoses and crossover pipe as necessary. Mark and disconnect spark plug wires at spark plugs.
2. Remove necessary accessory brackets. Separate inlet pipe from exhaust manifold. Remove exhaust manifold bolts. Remove exhaust manifold and gaskets (if equipped). To install, reverse removal procedure. Tighten bolts and nuts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__torque-specifications) .

VALVE COVERS

1. Disconnect negative battery cable. Drain cooling system. Remove heater hose to upper intake manifold before removing right-side valve cover.
2. Mark and disconnect spark plug wires at spark plugs. Remove necessary Air Injection Reaction (AIR) hoses and air cleaner. Mark and remove necessary electrical connectors.
3. Remove necessary accessories and brackets. Remove valve cover bolts. Use a block of wood and rubber mallet to loosen valve cover (if necessary). Remove valve cover and gasket. To install, reverse removal procedure. Tighten fasteners to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__torque-specifications) .

ROCKER ARMS & PUSH RODS

1. Remove valve covers. See «VALVE COVERS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__valve-covers) . Keep components in order for installation in original location and position.
2. Remove rocker arm nuts, balls, rocker arms and push rods. To install, reverse removal procedure. Tighten fasteners to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__torque-specifications) . Apply Prelube (3755008) to rocker arm and ball mating surface.

ROCKER ARM STUD

1. Remove rocker arm studs with Stud Remover (J 5802-01). Ream stud bore to replacement size of oversize stud. Oversize studs are available in .003" (.08 mm) and .013" (.33 mm).
2. Coat press-fit area of stud with hypoid axle lubricant. Install rocker arm stud with Stud Installer (J 6880) until it bottoms out on cylinder head.

CYLINDER HEAD

Note. Check and record compression before removing cylinder head. Remove cylinder head when engine is cold.

1. Remove intake manifold, exhaust manifold and valve covers. See «INTAKE MANIFOLD»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8), «EXHAUST MANIFOLD»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__exhaust-manifold) and «VALVE COVERS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__valve-covers).
2. Drain cooling system. Ensure components are kept in order for installation reference. Remove cylinder head bolts in 3 steps, in reverse order of tightening sequence. (Scheme 2) Remove cylinder head and gasket.

Inspection

Clean all carbon and gasket material from mating surfaces. Check cylinder head for warpage or cracks. Clean and tap cylinder head bolt holes and threads.

1. Coat steel-type head gaskets with sealer. DO NOT coat composition-type head gaskets with sealer. Install NEW head gasket on cylinder block. Install cylinder head. Coat head bolts with Sealing Compound (1052080).
2. Install head bolts finger tight. Tighten head bolts to specifications in 3 steps, in proper sequence. (Scheme 2) See «TORQUE SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__torque-specifications). To complete installation, reverse removal procedure.

Scheme 2

FRONT COVER & OIL SEAL

Note. It is not necessary to remove timing cover to replace timing cover seal.

1. Remove negative battery cable and serpentine drive belt. Remove crankshaft pulley bolts and remove pulley. Remove harmonic balancer-to-crankshaft bolt. (Scheme 3) Remove harmonic balancer using Harmonic Balancer Remover/Installer (J 23523-E).
2. Remove water pump. See «WATER PUMP»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__water-pump). Loosen or remove oil pan as necessary. See «OIL PAN»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8).
3. Remove Air Injection Reaction (AIR) assembly and A/C compressor mounting bracket. Remove front-cover-to engine bolts. Remove cover and gasket. Carefully pry seal from timing cover using a large screwdriver.

1. Install NEW oil seal in timing cover. Coat timing cover gasket with sealant and position on timing cover. Install timing cover and bolts. (Scheme 3) Tighten bolts finger tight.
2. Tighten bolts alternately and evenly to specifications. See «TORQUE SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__torque-specifications). Apply sealant to area where oil pan, cylinder block and timing cover join. To complete installation, reverse removal procedure.

Scheme 3

1. Remove front timing cover. See «FRONT COVER & OIL SEAL»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__front-cover-oil-seal). Rotate crankshaft until camshaft gear and crankshaft gear timing marks align when No. 6 cylinder is at TDC of compression stroke. (Scheme 4)
2. Remove 3 camshaft gear retaining bolts. Remove camshaft gear and chain as an assembly. (Scheme 3) If replacing crankshaft gear, use Gear Remover (J 5825-A) to pull gear off crankshaft.

Drive crankshaft gear on crankshaft, with timing mark facing out. Align timing marks on camshaft gear and crankshaft gear. When timing marks are properly aligned, No. 6 cylinder should be on TDC of compression stroke. (Scheme 4) Install camshaft gear and chain as an assembly. Tighten fasteners to specification. See TORQUE SPECIFICATIONS. To complete installation, reverse removal procedure.

Scheme 4

CAMSHAFT

Note. Rotate crankshaft in direction of normal operation only. Keep components in order for installation reference.

1. Remove valve covers. See «VALVE COVERS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__valve-covers) . Remove rocker arms but DO NOT remove push rods at this time. See «ROCKER ARMS & PUSH RODS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__rocker-arms-push-rods) . Measure lobe lift of camshaft with push rods installed.
2. To measure lobe lift, attach dial indicator to cylinder head. Position indicator pointer on tip of a push rod. Rotate crankshaft until push rod is at lowest point. Zero indicator and rotate crankshaft until push rod is at highest point. Record reading and repeat procedure for remaining lobes.
3. After lobe lift is measured, remove push rods. See «ROCKER ARMS & PUSH RODS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__rocker-arms-push-rods) . Remove intake manifold. See «INTAKE MANIFOLD»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8) . Remove timing chain and timing gears. See «TIMING CHAIN»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8) . Remove radiator and hoses.
4. Using approved refrigerant recovery/recycling equipment, discharge A/C system and remove condenser (if equipped). Remove valve lifters and camshaft retaining plate. Using three 5/16" x 18" x 4" bolts, pull camshaft from engine. Carefully remove camshaft without damaging camshaft bearings. Remove rear camshaft plug. Remove bearings with standard bearing remover.

Check camshaft for scratches, pits or loose fitting in bearings. Check camshaft journal diameter and lobe lift. See CAMSHAFT SPECIFICATIONS under ENGINE SPECIFICATIONS. Replace camshaft if damaged or not to specifications.

1. Install front and rear camshaft bearings first. Position No. 1 camshaft bearing oil holes at 1 o'clock and 5 o'clock positions. Position oil hole of No. 5 camshaft bearing at 12 o'clock position.
2. Position oil holes of camshaft bearings No. 2-4 at 5 o'clock position. Install rear camshaft plug flush and .031" (.79 mm) deep in block. Use sealant on camshaft plug.
3. If replacing camshaft, replace lifters, engine oil and filter. Apply Camshaft Prelube (3755008) to camshaft lobes. Apply engine oil to bearings and camshaft bearing journals. To complete installation, reverse removal procedure.

Remove transmission. On A/T equipped models, see REMOVAL & INSTALLATION - A/T article in AUTOMATIC TRANSMISSIONS. On M/T equipped models, see CLUTCHES article. On all models, remove flywheel/flexplate. Pry out seal with screwdriver, using notches in seal retainer. (Scheme 5)

1. Coat entire seal with engine oil. Install seal with Seal Installer (J 35621) until installer bottoms. (Scheme 5) Align crankshaft dowel to proper flywheel hole (if equipped).
2. Install and tighten flywheel/flexplate-to-crankshaft bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__torque-specifications). To complete installation, reverse removal procedure.

Scheme 5

WATER PUMP

Note. For additional cooling system information, see ENGINE COOLING article.

1. Disconnect negative battery cable and drain cooling system. Remove air cleaner and intake duct assembly. Disconnect MAF sensor electrical connector (if equipped). Remove accessory drive belt(s).
2. Remove fan assembly. Remove water pump damper (if equipped) and water pump pulley. Relieve fuel pressure and remove fuel lines as necessary for access. See «FUEL PRESSURE RELEASE»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8__fuel-pressure-release) . Remove accessories as necessary. Remove coolant hoses from water pump. Remove water pump bolts, water pump and gasket.

To install, reverse removal procedure. Tighten fasteners to specification. See TORQUE SPECIFICATIONS . Fill and bleed cooling system. See COOLING SYSTEM BLEEDING .

1. Disconnect negative battery cable. Raise vehicle and drain crankcase. Remove oil filter. Remove oil filter adapter at block. On A/T models, remove flexplate cover. On M/T models, remove starter and bellhousing cover.
2. On all models, remove oil cooler pipe at oil pan. Remove Electronic Spark Control (ESC) shield. Remove front crossmember braces. Remove oil pan bolts. Remove oil pan.

To install, reverse removal procedure. Apply Sealant (1052914) to front cover and cylinder block mating surfaces. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS .

GENERAL NOTE

Note. Mark components and keep together for installation to original location and position.

VALVE GUIDES

Check and service guides before servicing valve and seat. Guide replacement information is not available from manufacturer. Valve guides may be reamed to .003" (.08 mm), .015" (.38 mm) or .030" (.76 mm) oversize for installation of oversize valve.

VALVE SEAT

Valve seat replacement information is not available from manufacturer. Follow instructions of tool manufacturer for servicing valve seats. If seats are serviced, valves must be serviced or replaced.

VALVES

Check valves before servicing. Replace valves as necessary. See VALVES & VALVE SPRINGS under ENGINE SPECIFICATIONS. Valves may be machined to specifications.

VALVE SEAT CORRECTION ANGLES

If seat is too wide after grinding, use a 20-degree stone to lower, or a 70-degree stone to raise seat.

PISTON & ROD ASSEMBLY

1. Mark rod and rod cap with matching cylinder number. Before disassembling, match mark piston to rod for reassembly reference. Notch or dot on piston top should face front of engine. Piston pin is a press fit.
2. When measuring, pin bore and piston pin must be free of varnish or scuffing. If piston-to-pin clearance exceeds .001" (.03 mm), replace piston and pin as an assembly.

PISTON RINGS

Rings are marked and must be installed properly. Marked side of ring must face toward top of piston. Top compression ring is chrome or molybdenum faced. Second compression ring has a tapered face. Oil ring is a 3-piece type. Ensure end gaps are positioned properly on piston. (Scheme 6)

Scheme 6

FITTING PISTONS

Ensure notch or dot on piston top faces front of engine. Check pistons for wear or damage. Replace pistons as necessary. Check piston-to-cylinder bore clearance. If one cylinder must be bored, all cylinders must be bored to same oversize.

ROD BEARINGS

Ensure bearing cap bolt holes and mating surfaces are clean and dry. Use connecting rod stud protectors on all rod cap bolts. Install inserts in connecting rod and cap. Lubricate bearings and crank pin. Install bearing cap. Tighten rod bearing cap bolts.

CRANKSHAFT & MAIN BEARINGS

1. If bearing clearance is greater than specifications, replace upper and lower bearings. Service bearings are available in .001, .002, .009, .010 and .020" (.03, .05, .23, .25 and .51 mm) undersize. Ensure arrow on main bearing caps face engine front.
2. Tighten main bearing caps, except rear main cap, to 80 ft. lbs. (109 N.m). Tighten rear main cap to 12 ft. lbs. (15 N.m). Tap crankshaft rearward, then forward with lead hammer. This will align rear main bearing and crankshaft and thrust surfaces. Retighten all main bearing caps to 80 ft. lbs. (109 N.m).

THRUST BEARING

Check crankshaft end play by forcing crankshaft to extreme front position. Measure end play at front end of rear main bearing with a feeler gauge. If end play is not within specifications, replace thrust bearing. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS under ENGINE SPECIFICATIONS.

CYLINDER BLOCK

1. Check cylinder bore for wear, taper, out-of-round and piston fit. Cylinders with less than .005" (.13 mm) wear or taper may be honed.
2. Cylinders with greater than .005" (.13 mm) wear or taper must be bored to smallest oversize piston that will permit complete resurfacing of all cylinders. Machine cylinder or replace as necessary. See «CYLINDER BLOCK SPECIFICATIONS»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8) under ENGINE SPECIFICATIONS.

ENGINE OILING SYSTEM

A gear-type oil pump provides full pressure lubrication through full-flow oil filter. Oil pump is bolted to bottom of cylinder block, inside oil pan. Intermediate (drive) shaft is splined into the distributor and oil pump. Distributor is camshaft driven.

CRANKCASE CAPACITY

Crankcase capacity is 4 qts. (3.8L) without oil filter, and 5 qts. (4.7L) with oil filter.

MINIMUM OIL PRESSURE

Oil pressure with engine at normal operating temperature should be 6 psi (0.4 kg/cm 2 ) at 1000 RPM, 18 psi (1.3 kg/cm 2 ) at 2000 RPM and 24 psi (1.7 kg/cm 2 ) at 4000 RPM.

Removal & Disassembly

1. Remove oil pan. See «OIL PAN»(/chevrolet/corvette/c4-1984-1998/remont/mechanical/#57l-v8-vin-8) under REMOVAL & INSTALLATION. Remove oil pump retaining bolts and remove pick-up screen. Remove oil pump and intermediate shaft.
2. Remove oil pump cover screws and remove cover. Mark gear teeth for reassembly. Remove idler gear, drive gear and shaft. Remove pressure regulator pin, spring and valve from cover. Remove pick-up screen and pipe from cover only if replacing.

Check oil pump body and gears for cracks, wear and damage. Check oil pump shaft for looseness in housing. Check inside of cover for wear which would permit oil leakage. Replace oil pump assembly as necessary. Oil pump specifications are not available from manufacturer.

Reassembly & Installation

Clean all parts in solvent and dry using compressed air. To reassemble, reverse disassembly procedure. Tighten fasteners to specification. See TORQUE SPECIFICATIONS . To install, reverse removal procedure. See OIL PAN under REMOVAL & INSTALLATION.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

BEARING SPECIFICATIONS

CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECIFICATIONS

CONNECTING ROD SPECIFICATIONS

CONNECTING ROD SPECIFICATIONS

PISTON/PIN/RING SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS

CYLINDER BLOCK SPECIFICATIONS

CYLINDER BLOCK SPECIFICATIONS

VALVE/VALVE SPRING SPECIFICATIONS

VALVES & VALVE SPRINGS SPECIFICATIONS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

See also:
• ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
• REMOVAL & INSTALLATION - A/T
• CLUTCHES
• ENGINE IDENTIFICATION CODES
• FUEL PRESSURE RELEASE
• TORQUE SPECIFICATIONS
• COOLING SYSTEM BLEEDING
• VALVE COVERS
• EXHAUST MANIFOLD
• WATER PUMP
• FRONT COVER & OIL SEAL
• ROCKER ARMS & PUSH RODS
• CAMSHAFT SPECIFICATIONS