3.8l v6 - Vins [c,3 & 7] Buick LeSabre 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). VIN is 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

TROUBLE SHOOTING

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

ENGINE

See the ENGINE REMOVAL article in this section.

Removal (Non-turbo)

1. Disconnect negative battery 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 and cruise control 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 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. Scheme 1

Removal (Century, Cutlass Ciera, & Cutlass Cruiser)

1. Disconnect negative battery 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 steering gear. A damaged steering gear can cause loss of steering control and can result in vehicle being unsafe to drive.
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 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.

Removal - Left Side (All Others)

1. Disconnect negative battery cable. On Riviera and Toronado, remove engine strut and engine cooling fan. On all models, 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.

Removal - Right Side (All Others)

1. Disconnect negative battery cable. Remove spark plug wires oxygen sensor lead and EGR pipe. Remove transaxle oil level indicator tube.
2. Remove 2 nuts attaching exhaust crossover pipe to manifold. Remove exhaust manifold heat shield upper bolts (if equipped). Remove manifold bolts and manifold.

Note. If replacing exhaust manifold, transfer oxygen sensor and 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

1. Disconnect negative battery cable. Remove valve covers and intake manifold. Disconnect or remove exhaust manifolds. Remove ignition module, ignition wires, alternator bracket and A/C bracket.
2. Remove power steering pump, belt tensioner assembly and fuel line heat shield. Remove rocker arm assemblies, guide plate and pushrods. Remove or disconnect any remaining components interfering with head removal. Remove cylinder head bolts and cylinder head.

Inspection

Check cylinder head for damage. If more than .054" (.39 mm) must be removed from cylinder head to restore mounting surface flatness, replace cylinder head.

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 60 Ft. Lbs (81 N.m) at any time in step 2, you should stop at this point. Do not complete the balance of the 90° turn.
3. Reverse removal procedure to complete installation. Check for fluid leaks and verify fluid levels are correct.

Cylinder Head Tightening Sequence. Scheme 2

1. Disconnect negative battery 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 and support vehicle. 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, 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 3

Disconnect negative battery cable. Remove serpentine belt. Raise and support vehicle. 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 4) Remove camshaft thrust button and spring. Remove camshaft sprocket bolts, camshaft sprocket and chain. Remove crankshaft sprocket.

Timing Chain Sprocket Alignment. Scheme 4

1. Ensure 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 and tighten bolts.

1. Remove timing chain cover, balance shaft drive gear bolt, camshaft sprocket and timing chain. Remove balance shaft retainer bolts, retainer and balance shaft gear. Using Slide Hammer (J 6125-B), remove balance shaft.
2. Remove balance shaft rear plug. Using bearing driver (J 33049), drive balance shaft bearing out toward bellhousing side of engine. Inspect balance shaft rear bearing and journal for wear or scoring, replace parts as necessary.

Note. Always replace front bearing whenever balance shaft is removed.

1. Lubricate balance shaft rear bearing in clean engine oil. Using Installer (J 36995), install rear bearing. Install rear balance shaft plug. Using Driver (J 36996), install balance shaft. Install bearing shaft retainer and tighten bolts.
2. To complete installation, reverse removal procedure. Ensure balance shaft and camshaft marks are aligned properly. (Scheme 5)

Aligning "3800" Balance Shaft & Camshaft Marks. Scheme 5

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 6) 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 6

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 6) 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. Remove camshaft gear and balance shaft gear (if equipped). 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 procedure to complete installation.

Removal & Installation

1. Remove camshaft and rear cover plug. Using Camshaft Bearing Remover/Installer (J6098-01), remove inner bearings first. The front bearings are removed from rear by using a spacer between engine block and puller plate. NOTE: Once camshaft bearings have been removed, they can NOT be reused.
2. Reverse removal procedure 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.

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.

Inspection & Installation

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 7)

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

Rocker arms must be installed in original locations. Reverse removal procedure to complete assembly.

Rocker Arm Assemblies. Scheme 7

OIL PAN

Note. See OIL PAN REMOVAL article in this section.

1. With cylinder heads and oil pan removed, check top of cylinder bore for ridge. Remove ridge using a ridge reamer. Mark or identify pistons to ensure they are installed in original cylinders.
2. Remove rod nuts and cap. Remove piston and rod assemblies. Install rod caps on rods from which they were removed.

Scheme 8

1. Position rings on piston. (Scheme 8) Clean cylinder bores, pistons, and bearing journals thoroughly. Coat bearing surfaces, pistons, and cylinder bores with engine oil. (Scheme 8): Piston Ring Gap Positioning
2. Place bearing insert in rod. Position piston in bore so notch in top of piston is facing front of engine. Push piston into bore, carefully guiding rod over crankshaft until bearing is seated against journal. Install rod cap and bearing. Tighten rod cap nuts.

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.

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 & Components (1 of 2). Scheme 9

Oil Pump & Components (2 of 2). Scheme 10

OIL PUMP SPECIFICATIONS

Disconnect negative battery 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 the following articles in the ENGINE COOLING section

Cooling System Specifications

See appropriate article

COOLING SYSTEM SPECIFICATIONS - Century/Cutlass Ciera

COOLING SYSTEM SPECIFICATIONS - Electra/Park Avenue/98

COOLING SYSTEM SPECIFICATIONS - LeSabre/Delta 88/Bonneville

COOLING SYSTEM SPECIFICATIONS - Reatta

COOLING SYSTEM SPECIFICATIONS - Regal

COOLING SYSTEM SPECIFICATIONS - Riviera & Toronado

Serpentine Drive Belts

See appropriate article

DRIVE BELT ROUTING - Century/Cutlass Ciera

DRIVE BELT ROUTING - Electra/Park Avenue/98

DRIVE BELT ROUTING - LeSabre/Delta 88/Bonneville

DRIVE BELT ROUTING - Reatta

DRIVE BELT ROUTING - Regal

DRIVE BELT ROUTING - Riviera/Toronado

Electric Cooling Fan

See appropriate article

ENGINE COOLING FAN - Century/Cutlass Ciera

ENGINE COOLING FAN - Electra/Park Avenue/98

ENGINE COOLING FAN - LeSabre/Delta 88/Bonneville

ENGINE COOLING FAN - Reatta

ENGINE COOLING FAN - Regal

ENGINE COOLING FAN - Riviera/Toronado

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 SEAL INSTALLATION

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. Use oversize seals with oversize valves. If "O" ring type oil seals are used, ensure they are properly seated and not twisted.

HYDRAULIC VALVE LIFTER ASSEMBLY

If hydraulic valve lifters are being removed, mark or identify lifters to ensure they are installed in original position. 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, they should be tested using a leak-down rate tester after reassembly.

Exploded View of Hydraulic Lifter Assembly. Scheme 11

FITTING PISTONS

1. With piston and rod assembly removed, thoroughly clean cylinder bore. Inspect bore for taper or out-of-round. If cylinder taper is more than .004" (.01 mm), or is out-of-round more than .003" (.076 mm), cylinder must rebored and oversize piston and rings installed.
2. Measure piston diameter at 90 degree 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.

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.
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. Using Piston Pin Remover/Installer (J-24086) and press, install into piston and rod.

CONNECTING ROD BEARINGS

Note. Bearing ends 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 check journal for out-of-round and taper.
2. Check bearing-to-journal clearance using Plastigage method. If clearance exceeds specification, undersize bearing may be installed to obtain correct clearance. If clearance is excessive, crankshaft must be replaced. Measure rod side clearance.

MAIN BEARINGS

Note. Bearing ends 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. Inspect main bearing journal for wear or grooves. Check journal for out-of-round and taper.
2. Check bearing-to-journal clearance using Plastigage method. If clearance exceeds specification, undersized bearing may be installed to obtain correct clearance. If clearance is excessive, crankshaft must be reconditioned or replaced.

Removal & Installation (Crankshaft Removed)

1. Remove rope seal from rear main bearing cap and block. Clean bearing cap and seal grooves. Inspect for cracks. Apply Sealer (1052621) to cap seal contact surface. Wait one minute. Drive new rope seal into bearing cap with Seal Installer (J-25285A). Cut excess seal material flush with bearing cap.
2. Form new rope seal in rear seal groove in block. Push rope seal into block seal groove and trim excess. Apply sealant to mating surfaces. Lightly tap main bearing cap into place. Install main bearing cap bolts and tighten.

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. Check crankshaft end play.

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. If you are getting false oil pressure readings, check for a good ground at the oil pressure sensor base. See following procedures

1. Ground base of oil pressure sensor to battery negative terminal or a known good ground. If oil pressure reading is now correct, replace the 4 oil filter adapter-to-front cover retaining bolts and the adapter-to-front cover gasket. The new part numbers are: Gasket (PN 25529916) Bolts (4) (PN 25534181)
2. Tighten the NEW bolts to 12.5 Ft Lbs. (17 N.m).

PRESSURE REGULATOR VALVE

Pressure regulator valve is located in oil filter adapter and is nonadjustable.

ENGINE OILING SYSTEM DESCRIPTION

Engine 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

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

GENERAL SPECIFICATIONS

VALVE SPECIFICATIONS

VALVE SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS

Note. For pistons, pins and rings specifications, see PISTONS, PINS & RINGS SPECIFICATIONS (VIN C - LN3) , PISTONS, PINS & RINGS SPECIFICATIONS (VIN 3 - LG3) and PISTONS, PINS & RINGS SPECIFICATIONS (VIN 7 - LC2) .

PISTONS, PINS & RINGS SPECIFICATIONS (VIN C - LN3)

PISTONS, PINS & RINGS SPECIFICATIONS (VIN 3 - LG3)

PISTONS, PINS & RINGS SPECIFICATIONS (VIN 7 - LC2)

BEARING SPECIFICATIONS

CRANKSHAFT MAIN & CONNECTING ROD BEARING SPECIFICATIONS

VALVE SPRING SPECIFICATIONS

VALVE SPRINGS SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

See also:
• COOLING SYSTEM SPECIFICATIONS
• DRIVE BELT ROUTING
• DRIVE BELT ROUTING
• ENGINE COOLING FAN
• ENGINE COOLING FAN
• PISTONS, PINS & RINGS SPECIFICATIONS (VIN C - LN3)