3.8l v6 - VIN [3] Buick Electra VI

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 from Vehicle Identification Number (VIN) stamped on metal tab located on top of instrument panel at lower left of windshield. The VIN number code also appears as part of production or unit number stamped on left rear of cylinder block on all models. The VIN number contains 17 characters. The 8th character identifies engine. The 10th character identifies model year.

ENGINE IDENTIFICATION CODES

VALVE CLEARANCE ADJUSTMENT

Hydraulic lifters are used, no valve adjustments are required.

TROUBLE SHOOTING

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

ENGINE

Refer to the ENGINE REMOVAL article in this section.

Removal

1. Disconnect battery negative cable. Remove mass airflow sensor and air intake duct. Drain cooling system. Disconnect upper radiator hose and heater hose. Remove serpentine accessory drive belt, alternator and bracket.
2. Disconnect Computer Controlled Coil Ignition (C(3)I) module and wiring. Remove and label vacuum lines and wiring connectors as necessary. Remove throttle, cruise control and T.V. cables from throttle body.
3. Remove fuel lines, fuel rail and injectors. Remove spark plug wires. Remove intake manifold bolts. Remove intake manifold and gasket.

Note. Clean gasket surfaces on intake manifold and cylinder heads.

Installation

Install new intake manifold gaskets and position new rubber seals on front and rear rails on cylinder block. Ensure that pointed end of seal fits tightly against block and heads. Apply RTV sealer to ends of seals. Install intake manifold and tighten bolts in sequence. To complete installation, reverse removal procedure. (Scheme 1)

Intake Manifold Tightening Sequence Note position of mounting studs. Scheme 1

Removal (Bonneville/Century/Cutlass Ciera/Riviera/Toronado)

1. Disconnect battery negative cable. On right side manifold, remove pinch bolt at intermediate shaft. Separate intermediate shaft from rack and pinion stub shaft. CAUTION: Failure to separate intermediate shaft from rack and pinion stub shaft can result in damage to the steering gear. A damaged steering gear can cause loss of steering control and may result in vehicle crash.
2. Raise and support vehicle. Remove 2 bolts attaching exhaust pipe to manifold. Lower vehicle. Disconnect upper engine support strut. Place a jack under front crossmember of cradle and raise jack until vehicle begins to rise.
3. Remove 2 front body mount bolts. Remove body mount bolt cushions and thread body mount bolts and retainers into cage bolts at least 3 turns. Release jack slowly. Remove power steering pump and bracket from cylinder head and exhaust manifold.
4. On left side of engine, remove upper engine support strut. Remove 2 nuts attaching crossover pipe to manifold. Remove exhaust manifold bolts and manifolds.

Note. If replacing an exhaust manifold, transfer O2 sensor and/or exhaust pipe seal to new manifold.

Clean sealing surfaces of exhaust manifolds and cylinder heads. Install manifolds by reversing removal procedure. Tighten exhaust manifold bolts and check for exhaust leaks.

Removal - Left Side (Delta 88/Electra/Lesabre/Ninety-Eight)

1. Disconnect battery negative cable. Remove mass airflow sensor, air intake duct and PCV pipe. Remove 2 nuts attaching crossover pipe to manifold. Remove spark plug wires.
2. If necessary, remove oil level indicator and tube to provide additional clearance. Remove exhaust manifold bolts and manifolds.

Installation - Right Side

1. Disconnect battery negative cable. Remove mass airflow sensor, air intake duct and PCV pipe. Disconnect IAC wiring at throttle body. Remove spark plug wires and O2 sensor lead.
2. Remove heater inlet pipe from manifold studs. Remove 2 nuts attaching crossover pipe to manifold. Remove front alternator support bracket. Remove exhaust manifold bolts and manifolds.

Note. If replacing an exhaust manifold, transfer oxygen sensor and/or exhaust pipe seal to new manifold.

Clean sealing surfaces of exhaust manifolds and cylinder heads. Install manifolds by reversing removal procedure. Tighten exhaust manifold bolts and check for exhaust leaks.

CYLINDER HEAD

Note. Before removing valve covers and intake manifold, clean dirt from head and adjacent areas.

Removal (Bonneville/Century/Cutlass Ciera/Riviera/Toronado

1. Disconnect battery negative cable and remove serpentine drive belt. Remove alternator, power steering pump and mounting bracket from right side cylinder head.
2. Remove oil dipstick, air pump and mounting bracket from left side cylinder head. Remove spark plug wires and exhaust manifold bolts. Remove intake manifold. See INTAKE MANIFOLD REMOVAL in this article.
3. Remove valve covers, rocker arms and pushrods. Index mark all parts for reassembly reference. Remove cylinder head bolts and cylinder heads. Discard used cylinder head bolts.

1. Clean cylinder block head bolt threads. Position new head gasket on block deck. Place head on head gasket. Coat new head bolts with sealer and install.
2. Tighten head bolts evenly in sequence to 25 ft. lbs. (35 N.m). (Scheme 2) Tighten bolts in sequence an additional 90 degrees without exceeding maximum torque specification of 60 Ft. Lbs. (81 N.m). Again tighten bolts in sequence an additional 90 degrees without exceeding maximum torque specification. CAUTION: Should you reach maximum torque, tightening procedure should be stopped. Replace or repair part(s) as necessary.
3. Reverse removal procedure to complete installation. Check for fluid leaks and verify fluid levels are correct.

Note. Before removing valve covers and intake manifold, clean dirt from head and adjacent areas.

Removal (Delta 88/Electra/Lesabre/Ninety-Eight)

1. Disconnect battery negative cable and drain coolant. Remove intake and exhaust manifolds as previously described. Remove alternator, power steering pump and brackets.
2. Remove rocker arms and pushrods. Index mark all parts for reassembly reference. Remove cylinder head bolts and cylinder heads.

Note. Install new cylinder head bolts whenever cylinder head and/or gasket is removed.

Scheme 2

1. Position head on block. Coat head bolts with sealer and install. Tighten head bolts evenly in sequence, using 4 steps. (Scheme 2) (Scheme 2): Cylinder Head Tightening Sequence Tighten head bolts in 4 steps.
2. Reverse removal procedure to complete installation. Check fluid levels and for fluid leaks.

Raise car and suitably support. Support weight of engine at forward edge of oil pan. Remove mount to cylinder block bolts. Raise engine slightly. Remove mount to mount bracket bolt and nut. Remove mount.

Install mount to cylinder block bolts and tighten. Lower engine. Install mount to mount bracket bolt and tighten to. Remove frame support and lower car.

Inspection

Inspect for proper completion of repair and for mount alignment

Engine Mounting. Scheme 3

VALVE ARRANGEMENT

E-I-E-I-I-E (left side, front-to-rear).

E-I-I-E-I-E (right side, front-to-rear).

VALVE GUIDE SERVICING

If valve stem clearance is excessive, replace valve. Some valves with oversize stems are used in production and can be identified by stamped number on back side of valve head. Oversize valve guides and valve guide reamers are available in .003" (.08 mm), .006" (.15 mm), and .010" (.25 mm) oversize. When reconditioning, always use next oversize reamer and replacement valve.

VALVE STEM OIL SEALS

Valve stem oil seals are installed on intake valve guides. A new seal should be installed whenever valve spring is removed. To install new seals, carefully slide seal over valve stem and push down until it contacts valve guide. Push seal onto guide until seal bottoms against guide.

Note. If "UMBRELLA" type oil seals are used, seat them on valve guides and use oversize seals with oversize valves. If "O" ring type oil seals are used, ensure they are properly seated and not twisted.

With cylinder head removed, compress valve spring with spring compressor and remove valve keepers. Release spring compressor and remove spring retainer and spring. Remove valve stem oil seal from intake valves.

Check valve springs in a valve spring tester and replace as necessary. Both intake and exhaust valve springs may be installed with either end up. Reverse removal procedure to complete installation.

Remove valve cover, rocker arm retaining bolts, pedestal retainer, rocker arm and pedestal. Inspect rocker arms for wear, scoring, or damage. Replace components as necessary. (Scheme 4)

Note. Place rocker arm assemblies on a clean surface and note component locations for correct reassembly.

Reverse removal procedure to assemble rocker arms. Rocker arms must be installed in original locations.

Rocker Arm Assemblies Install rocker arm assemblies in original locations. Scheme 4

HYDRAULIC VALVE LIFTER ASSEMBLY

If hydraulic valve lifters are being removed, mark or identify lifters to ensure that they are installed in original position. The lifters are serviced as complete assemblies only. If lifter is damaged or worn, complete lifter must be replaced. If lifters are disassembled for cleaning and inspection, after reassembly they should be tested using a leak-down rate tester.

Exploded View of Hydraulic Lifter Assembly. Scheme 5

Bonneville

Disconnect negative battery cable. Raise and support vehicle. Drain crankcase. Remove flywheel access cover and crossover pipe. Disconnect engine mounts. Raise and support engine. Remove oil pan bolts and oil pan.

Century

Disconnect negative battery cable. Raise and support vehicle. Drain crankcase and remove flywheel access cover. Remove oil pan bolts and oil pan.

Electra, Lesabre, Regal, & Skylark

Disconnect negative battery cable. Raise and support vehicle. Drain crankcase. Remove flywheel access cover and crossover pipe. Disconnect engine mounts. Raise and support engine. Remove oil pan bolts and oil pan.

Riviera

1. Disconnect negative battery cable. Remove upper final drive bolt and support engine. Raise and support vehicle. Disconnect idler arm at frame.
2. Lock steering against left-turn stop. Remove final drive unit, splash shield, starter and flywheel access cover. Drain crankcase, remove oil pan bolts and oil pan.

Cutlass Ciera, Delta 88, 98, & Toronado

Disconnect negative battery cable. Raise and support vehicle. Drain crankcase and remove oil filter. Remove flywheel access cover, oil pan bolts, oil pan tensioner spring and oil pan.

1. With cylinder heads removed, check top of cylinder bore for ridge. With piston at bottom of stroke and covered with cloth to catch cuttings, remove ridge using a ridge reamer. Mark or identify pistons to cylinders to ensure that they are installed in original position.
2. With oil pan removed, rotate engine until number 1 piston is down. Remove rod nuts and cap. Install thread protectors on rod bolts and push piston and rod assembly out through top of cylinder bore. Follow same procedure to remove remaining piston and rod assemblies. Install rod caps on rods from which they were removed.

Scheme 6

1. Position rings on piston. (Scheme 6) Clean cylinder bores, pistons, and bearing journals thoroughly. Coat bearing surfaces, pistons, and cylinder bores with engine oil. Rotate crankshaft until rod journal of piston and rod assembly being installed is down. (Scheme 6): Piston Ring Gap Positioning
2. Place bearing insert in rod and install thread protectors on rod bolts. Using a ring compressor, compress piston rings. Position piston in bore so that notch in top of piston is facing toward front of engine. Push piston into bore, carefully guiding rod over crankshaft until bearing is seated against journal. Remove thread protectors and install rod cap and bearing. Tighten rod cap nuts.

FITTING PISTONS

1. With piston and rod assembly removed, thoroughly clean cylinder bore. Inspect bore for taper or out-of-round.
2. If cylinder tapers more than .005" (.13 mm) or is out-of-round more than .003" (.076 mm), cylinder must be bored and an oversize piston and rings installed.
3. Measure piston diameter at 90° angle to piston pin and .25" (6.35 mm) below oil ring groove. If clearance between piston and cylinder is excessive, cylinder must be bored and oversize pistons and rings installed.

FITTING RINGS

1. Position a ring in cylinder bore where it will be used. Push ring down to a point in bore to where ring wear is not encountered. Use head of piston to position ring squarely in bore.
2. Measure gap between ends of ring using a feeler gauge. If not to specification, file ends of rings carefully using a smooth file to obtain proper ring gap. (Scheme 7)

Checking Piston Ring End Gap Place ring at bottom of piston travel. Scheme 7

Note. Use care to avoid damage to ring and/or cylinder bore.

PISTON PIN INSTALLATION

1. Piston pin is a press fit in connecting rod. Using a Piston Pin Remover/Installer (J-24086) and a press, remove piston pin and separate piston and rod. (Scheme 8)
2. Inspect pin for wear and/or scoring. Check clearance of pin in piston. If clearance is excessive, piston and pin assembly must be replaced.
3. Place connecting rod in correct position for bank in which piston and rod are being installed. Lubricate piston pin and press it into piston and rod, using Piston Pin Remover/Installer (J-24086) and press used during removal process. (Scheme 8)

Piston Pin Removal & Installation. Scheme 8

CONNECTING ROD BEARINGS

Note. The ends of bearings must never be filed flush with parting surfaces of rod cap or cylinder block and cap.

1. With connecting rod cap removed, inspect bearings for flaking or wear. Check connecting rod journal for scoring or grooves. Measure rod journal with a micrometer and check journal for out-of-round. Journal out-of-round should not exceed .0015" (.038 mm).
2. Check bearing-to-journal clearance using Plastigage method. If clearance exceeds .003" (.08 mm), select fit undersize bearing may be installed to obtain correct clearance.
3. If clearance is excessive, crankshaft must be reconditioned or replaced. Measure rod side clearance using a feeler gauge. The clearance should be .005-.026" (.13-.66 mm).

MAIN BEARINGS

Note. The ends of bearings must never be filed flush with parting surfaces of rod cap or cylinder block and cap.

1. The upper bearing halves are grooved to supply oil to connecting rod bearings. The lower cap bearing halves are not grooved. With main bearing cap removed, inspect bearing for flaking or scoring.
2. Inspect main bearing journal for wear or grooves. Check journal for out-of-round conditions with a micrometer. If journal is out-of-round more than .0015" (.038 mm), crankshaft must be replaced. NOTE: To remove upper bearing, place a cotter pin in crankshaft oil hole and rotate crankshaft. When installing bearing caps, arrows must point to front of engine.
3. Check bearing-to-journal clearance using Plastigage method. If clearance exceeds .003" (.08 mm), select fit undersized bearing may be installed to obtain correct clearance. If clearance is excessive, crankshaft must be reconditioned or replaced.

REAR MAIN BEARING OIL SEAL

Note. The upper half of seal can only be replaced if crankshaft is removed. A seal that leaks can be repaired without being replaced.

Oil Seal Replacement

1. With crankshaft removed, pry old seals out of cylinder block and main bearing cap. Apply RTV sealer to seal groove. Within 1 minute, install a new rope seal and insert Seal Installer (J-28693/BT-2318) against one end of seal in block.
2. Pack seal until it is tight, by driving against seal with installer. The seal should be packed approximately .25" to .75" (6 to 19 mm) above edge of cylinder block. Repeat same procedure on bearing cap.
3. Measure amount that is packed into groove and add .062" (1.6 mm). Measure total distance on seal that was removed from main bearing cap and cut off same amount. Cut off same amount for opposite side. Replace crankshaft. Apply RTV sealer to mating surface of rear bearing cap and install bearing caps.

Main Bearing Cap Side Seals

Neoprene seals are placed on sides of bearing cap. The seals are slightly undersize when newly installed (and may leak) since neoprene composition swells in presence of heat and oil. The seals are slightly longer than grooves in cap, but should not be cut off.

Soak seals in light oil or kerosene for 5 minutes before installation. After seals are installed, tap them into cap with hammer handle. Apply sealant to mating surface of main bearing cap before installing.

THRUST BEARING ALIGNMENT

With thrust bearing cap bolts finger tight, move crankshaft rearward, then forward. Tighten main bearing cap bolts and rotate crankshaft. Be sure there is no excessive drag. Using a dial indicator, check crankshaft end play, it should be .003-.009" (.08-.23 mm).

1. Disconnect battery negative cable. Drain cooling system and disconnect radiator hoses and heater hose at water pump. Loosen water pump pulley and bolts. Remove serpentine drive belt. Remove water pump pulley. Raise vehicle and support. Remove right tire and wheel assembly.
2. Remove right, inner fender splash shield. Drain engine oil. Remove crankshaft balancer and oil filter. Remove water pump and crankshaft sensor. Remove oil pan and front cover.

Note. Whenever front cover is removed, the oil pump may lose its prime. Remove oil pump cover and pack petroleum jelly tightly around oil pump gears.

To install, reverse removal procedure. Ensure gasket surfaces are clean, and use a new gasket. Use sealer on bolt threads.

Engine Front Cover Assembly. Scheme 9

Disconnect battery negative cable. Remove serpentine belt. Raise vehicle and support. Remove right tire and wheel assembly. Remove inner fender splash shield. Remove crankshaft balancer and bolt. Pry out seal with screwdriver. Avoid damage to seal bore or seal contact area.

Install new seal using Seal Installer (J-35354). Coat seal surface with lubricant (GM 1050169). Install crankshaft balancer and bolt. Reverse removal procedure to complete installation.

With front cover removed, rotate engine until timing marks on sprockets are aligned. (Scheme 10) Remove camshaft thrust button and spring. Remove camshaft sprocket bolts, camshaft sprocket and chain. Remove crankshaft sprocket.

Timing Chain Sprocket Alignment. Scheme 10

1. Ensure that No. 1 piston is at TDC and align camshaft timing marks. Carefully install timing chain and sprockets without disturbing alignment of marks.
2. Install camshaft sprocket bolts and tighten. Install camshaft thrust spring, button, and timing chain dampers. Install front cover, bolts and tighten bolts.

Removal (In Vehicle)

1. Disconnect the negative battery cable. Remove serpentine belt from crankshaft. Raise and support vehicle. Remove right front tire and wheel assembly. Remove right inner fender access cover.
2. Using a 28mm socket, remove harmonic balancer retaining bolt. Remove harmonic balancer. Disconnect the crankshaft sensor electrical connector.
3. Remove the crankshaft sensor retaining and pinch bolts. (Scheme 11) Remove the crankshaft sensor and mounting bracket as an assembly from engine block. Remove the crankshaft sensor from its mounting bracket.

1. Loosely install the crankshaft sensor onto its mounting bracket. Position the sensor/bracket assembly onto the Alignment Tool (J-37089). Position the Alignment Tool onto the crankshaft.
2. Install and tighten the crankshaft sensor retaining bolts to 22 Ft. Lbs. (30 N.m). Install and tighten the mounting bracket pinch bolt to 89 INCH Lbs. (10 N.m). Remove the Alignment Tool from the crankshaft sensor/bracket assembly. Place the Alignment Tool onto the harmonic balancer and turn the harmonic balancer.
3. If any vane of the harmonic balancer touches the Alignment tool, replace the balancer assembly. Install the balancer onto the crankshaft. Tighten the harmonic balancer retaining bolt to 219 Ft. Lbs. (298 N.m). Install inner fender shield.
4. Install the right front tire and wheel assembly. Tighten the lug nuts to 100 Ft. Lbs (140 N.m). Lower vehicle and install the serpentine belt.

Removing/Installing Crankshaft & Camshaft Sensors. Scheme 11

Disconnect the negative battery cable. Remove water pump pulley retaining bolts. Remove serpentine belt. Remove water pump pulley. Remove the weather pack connector. Remove the camshaft sensor retaining bolt. (Scheme 11) Pull and twist the sensor to remove it from the engine front cover.

Lubricate the camshaft sensor "O" ring. Push and twist the camshaft sensor to install. Install the sensor retaining bolt, weather pack connector, water pump pulley, and serpentine belt. Tighten the camshaft sensor retaining bolt to 75 INCH Lbs. (8.5 N.m). Install and tighten the water pump pulley retaining bolts to 115 INCH Lbs. (13 N.m). Reconnect the negative battery cable.

Remove intake manifold, rocker arm assemblies, push rods, and lifters. Mark or identify push rods and lifters for installation in original position. Remove front engine cover and timing chain with sprockets. Carefully slide camshaft out to avoid damaging camshaft bearings or lobes.

Thoroughly clean and inspect camshaft. Lubricate journals and camshaft lobes. Carefully insert camshaft taking care not to damage bearings or camshaft lobes. Reverse removal procedures to complete installation.

CAMSHAFT BEARINGS

1. Remove camshaft and rear cover plug. Using Camshaft Bearing Remover/Installer (J6098-01), remove inner bearings first. The front bearings are removed by using a spacer between engine block and puller plate are removed from rear. NOTE: DO NOT reuse camshaft bearings once they have been removed.
2. Reverse removal procedures to install bearings and carefully pull them into place using Camshaft Bearing Remover/Installer (J6098-01). Be sure oil holes in bearings and journal are aligned. Apply RTV sealer to camshaft rear cover before installation.

Disconnect battery negative cable. Loosen water pump pulley and bolts. Remove serpentine belt. Drain cooling system and remove hoses from water pump. Remove water pump attaching bolts and water pump.

If installing a new water pump, transfer pulley from old pump. Clean all sealing surfaces. Apply sealant to water pump sealing surface. While sealer is tacky, install water pump and tighten attaching bolts. To complete installation, reverse removal procedure.

Note. For further information on cooling system capacities and other cooling system components, see ENGINE COOLING SYSTEMS article in this section.

CRANKCASE CAPACITY

Crankcase capacity is 5 quarts (4.7L) with filter change; 4 quarts (3.8L) without.

NORMAL OIL PRESSURE

Normal oil pressure should be 37 psi (2.60 kg/cm 2 ) at 2400 RPM.

PRESSURE REGULATOR VALVE

Pressure regulator valve is located in oil filter adapter and is non-adjustable.

ENGINE OILING SYSTEM

The lubrication is a force-feed type. The oil is supplied under full pressure to crankshaft, connecting rods, camshaft bearings, and valve lifters. A controlled volume of oil is supplied to rocker arms and push rods. All other moving parts are lubricated by splash or gravity flow.

Engine Oiling System. Scheme 12

Remove engine front cover. Remove oil filter adapter, pressure regulator valve and valve spring. Remove oil pump cover attaching screws and cover. Remove pump gears.

Thoroughly clean all components and inspect for wear or damage. Check fit of valve in bore. If clearance is excessive, replace valve and/or cover. Place a straightedge across gears and measure clearance between straightedge and gasket surface with a feeler gauge. The specified clearance is .001-.0035" (.025-.089 mm). If clearance is less than .001" (.025 mm), check gear pocket for wear.

Lubricate gears with oil. Assemble gears in housing. Pack pump cavity with petroleum jelly and install pump cover. Install pressure regulator valve spring and valve. Install oil filter adapter using new gasket. Tighten oil filter adapter bolts. Install front cover on engine.

Oil Pump and Components. Scheme 13

OIL PUMP SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

GENERAL SPECIFICATIONS

VALVE SPECIFICATIONS

VALVE SPECIFICATIONS

PISTON/PIN/RING SPECIFICATIONS

PISTONS, PINS, RINGS

BEARING SPECIFICATIONS

CRANKSHAFT MAIN & CONNECTING ROD BEARINGS

VALVE SPRING SPECIFICATIONS

VALVE SPRINGS

CAMSHAFT SPECIFICATIONS

CAMSHAFT

See also:
• ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION