3.1L v6 - VIN [T] Buick Regal III

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 by Vehicle Identification Number (VIN), engine block code or partial VIN. VIN is stamped on a metal pad located near lower left corner of windshield. The eighth character of VIN identifies engine model ("T" indicates 3.1L PFI engine). The tenth character of VIN identifies model year ("N" indicates 1992 model year). Do not confuse VIN with the 9-character partial VIN shown in Fig. (Scheme 1). The engine block code (3 characters) is stamped on left side of cylinder block, at cylinder block-to-transaxle/transmission flange (LHO indicates 3.1L PFI engine).

ENGINE IDENTIFICATION CODES

Scheme 1

VALVE CLEARANCE ADJUSTMENT

Note. If valves and seats are reconditioned, adjustable rocker arm studs must be installed. Adjustment procedure is for adjustable rocker arm studs only. Engines with original rocker arm studs are not adjustable and rocker arm nut is torqued to a specified torque. See TORQUE SPECIFICATIONS .

1. Bring No. 1 cylinder to firing position and align timing marks on front cover and harmonic balancer. Adjust exhaust valves on cylinders No. 1, 2 and 3 by backing off adjusting nut until valve lash is felt at pushrod.
2. Tighten adjusting nut (while rotating pushrod) until all valve lash is eliminated. Tighten adjusting nut an additional 1-1/2 turns. Repeat adjustment on intake valves for cylinders No. 1, 5 and 6.
3. Turn engine one revolution to cylinder No. 4 firing position. Adjust exhaust valves on cylinders No. 4, 5 and 6. Adjust intake valves on cylinders No. 2, 3 and 4.

TROUBLE SHOOTING

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

FUEL PRESSURE RELEASE

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.

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.

ENGINE

Note. On Beretta and Corsica, engine and transaxle are removed as an assembly from bottom of vehicle.

Removal & Installation (Beretta & Corsica)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE. Remove air cleaner assembly and battery. Drain coolant.
2. Disconnect transaxle fluid cooler lines from radiator. Remove transaxle fluid level indicator. Disconnect upper and lower radiator hoses from engine. Disconnect heater outlet hose from water pump. Disconnect heater inlet hose from rear of engine.
3. Remove serpentine drive belt. Remove transaxle shift cable and linkage from mounting bracket. Disconnect accelerator cable and cruise control cable (if equipped) from throttle linkage. Disconnect A/C pressure switch connector. Remove vacuum check valve from brake booster, leaving hose attached to valve.
4. Disconnect canister purge vacuum line and upper wiring harness from engine. Disconnect vacuum hose from vacuum reservoir. Raise and support vehicle. Remove front wheels. Remove right splash shield and oil filter. Disconnect lower wiring harness from engine.
5. Remove A/C compressor, leaving refrigerant hoses and rear bracket attached to compressor, and hang aside. Disconnect exhaust downpipe from manifold. Disconnect brake hose brackets from struts. Remove brake calipers.
6. Disconnect tie rods from struts. Lower vehicle enough to place power train support under frame. Remove bolts from suspension supports. Lower power train assembly. To install, reverse removal procedure. Fill cooling system.

Removal & Installation (Camaro & Firebird)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE. Disconnect negative battery cable. Remove hood. Remove air cleaner duct. Remove serpentine drive belt.
2. Remove A/C compressor with hoses attached, and lay aside. Drain coolant. Remove upper and lower radiator hoses and coolant recovery hose. Disconnect heater hoses. Disconnect throttle cable and cruise control cable (if equipped) from throttle body.
3. Disconnect vacuum brake booster hose. Remove distributor cap, and lay aside with spark plug wires connected. Disconnect necessary electrical connectors and vacuum lines. Remove power steering pump with hoses attached, and lay aside.
4. Raise and support vehicle. Disconnect transmission fluid cooler line clips from engine oil pan. Remove exhaust crossover pipe. Remove flexplate cover and torque converter bolts (A/T models). Disconnect starter wires. Remove transmission-to-engine bolts.
5. Remove motor mount through bolts. Lower vehicle. Disconnect fuel lines. Support transmission. Connect engine hoist. Lift engine slightly and disconnect ground wire from bracket at left rear of engine. Remove engine. To install, reverse removal procedure. Fill cooling system.

Removal & Installation (Cavalier & Sunbird)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE. Remove air cleaner and ducts. Disconnect negative battery cable. Drain coolant.
2. Remove exhaust manifold crossover pipe, serpentine drive belt and belt tensioner. Remove belt idler (if equipped). Remove upper and lower radiator hoses. Disconnect cables from bracket on upper intake manifold.
3. Remove alternator. Disconnect engine wiring harness and fuel lines. Disconnect coolant by-pass and overflow hoses. Support engine from top of vehicle using Engine Support (J-28467-A).
4. Raise and support vehicle. Remove right inner fender splash shield, flexplate/flywheel cover and starter. Remove A/C compressor. Disconnect exhaust downpipe from manifold. Remove torque converter bolts (A/T models). Remove engine mounts.
5. Remove intermediate shaft (drive axle) bracket-to-cylinder block bolts (M/T models). Disconnect shift control cable(s), and remove shift cable bracket from transaxle. Remove lower transaxle-to-engine bolts. Lower vehicle. Disconnect heater hoses from heater core.
6. Install engine hoist. Remove engine support from top of engine. Remove engine. Support transaxle. Remove remaining transaxle-to-engine bolts. To install, reverse removal procedure. Fill cooling system.

Removal & Installation (Cutlass Supreme, Grand Prix, Lumina & Regal)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE. Remove hood. Remove air cleaner and ducts. Disconnect battery cables. Drain coolant.
2. Disconnect necessary electrical connectors (except those on main engine harness) and fuel lines. Disconnect brake vacuum hoses at throttle body and brake booster. Disconnect control cables from throttle body.
3. Remove exhaust crossover pipe, serpentine drive belt and radiator hoses. Remove bolts from A/C front mounting bracket. Remove power steering pump with hoses attached, and set aside. Disconnect heater hoses from engine.
4. Raise and support vehicle. Remove A/C compressor, flexplate/flywheel cover and starter. Remove torque converter bolts (A/T models). Remove transaxle bracket, engine front mount nuts and exhaust downpipe. Lower vehicle.
5. Remove engine torque struts. Disconnect bulkhead electrical connector. Support transaxle. Remove transaxle-to-engine bolts. Attach engine hoist, and remove engine. To install, reverse removal procedure. Fill cooling system.

Removal (Camaro & Firebird)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Drain cooling system. Remove throttle body, plenum and fuel rail. Disconnect spark plug wires at plugs and coil wires.
2. Remove distributor cap and spark plug wires. Mark distributor position. Remove distributor hold-down bracket, and remove distributor. Disconnect canister purge vacuum hoses. Remove valve covers.
3. Remove upper radiator hose at intake manifold. Disconnect coolant sensor electrical connector. Remove heater inlet pipe from intake manifold. Remove alternator and bracket.
4. Remove center intake manifold bolts, center intake manifold and gasket. Remove transmission dipstick. Remove remaining intake manifold bolts. Remove intake manifold. Discard gaskets, and remove loose RTV from front and rear ridges of cylinder case.

Installation

1. Apply a 3/16" bead of RTV on each ridge. Install new intake gaskets on cylinder heads. Hold intake gaskets in place by extending a 1/4" bead of RTV onto gasket ends.
2. New intake gasket will have to be cut to install behind push rods. Install intake manifold on engine. Ensure areas between case ridges and intake are completely sealed.
3. Install intake manifold bolts. Tighten intake manifold bolts in sequence to 19 ft. lbs. (26 N.m). (Scheme 2) Install center intake manifold using new gasket. Install center intake manifold bolts, and tighten to 15 ft. lbs. (20 N.m). To install remaining components, reverse removal procedure.

Scheme 2

Scheme 3

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Remove air cleaner assembly. Disconnect negative battery cable. Remove engine strut mounts from strut bracket.
2. Disconnect control cables from throttle body. Disconnect brake booster vacuum pipe from upper intake manifold. Remove control cable bracket from upper intake manifold. Disconnect air intake duct from throttle body.
3. Remove throttle body from upper intake manifold. Remove EGR valve. Remove spark plug wiring harness from upper intake manifold. Remove upper intake manifold and gaskets. (Scheme 3) Disconnect fuel lines from fuel rail. Remove serpentine drive belt and alternator.
4. Remove power steering hose bracket from alternator bracket. Remove power steering pump with hoses attached, and lay aside. Disconnect fuel injector connectors. Remove fuel rail. Remove spark plug wiring harness from lower intake manifold.
5. Drain cooling system. Disconnect heater hoses from water pump and cylinder head. Remove left valve cover. Remove PCV hose and alternator brackets. Remove right valve cover. Remove upper radiator hose. Disconnect necessary electrical connectors.
6. Remove coolant temperature sensor. Remove necessary fuel lines. Remove throttle body heater hose. Remove heater hose from lower intake manifold. Remove lower intake manifold bolts, maintaining Belleville washers in same orientation on 4 center bolts. Remove lower intake manifold.
7. Loosen rocker arm nuts. Rotate rocker arms to one side, and remove push rods. Note push rod location for installation reference. Push rod lengths differ. Intake push rods are shortest and are marked orange. Exhaust push rods are longest and are marked blue. Remove lower intake manifold gasket.

1. Apply bead of RTV sealant to front and rear ridges of cylinder block sealing surfaces. Install new intake manifold gaskets on cylinder heads. Ensure all holes are aligned. CAUTION: Ensure gaskets are properly installed. Gaskets may be marked for proper direction of installation.
2. Install push rods and rocker arms in original locations. Tighten rocker arm nuts to 18 ft. lbs. (24 N.m). Install intake manifold. Tighten intake manifold bolts in sequence to 15 ft. lbs. (20 N.m). (Scheme 3) Tighten bolts again in sequence to 24 ft. lbs. (33 N.m).
3. To install remaining components, reverse removal procedure. Use new gaskets between lower and upper intake manifolds. Use new "O" rings for fuel system components. Fill cooling system.

Removal (Beretta & Corsica)

Remove air cleaner assembly. Disconnect negative battery cable. Remove radiator fan. Remove exhaust heat shield. Disconnect exhaust crossover pipe from manifold. Remove exhaust manifold and gasket.

Disconnect negative battery cable. Raise and support vehicle. Disconnect exhaust crossover pipe from manifold. Lower vehicle. Remove rear power steering pump bracket. Remove exhaust manifold and gasket.

Removal (Cavalier & Sunbird)

Disconnect negative battery cable. Drain coolant. Disconnect air cleaner inlet hose. Disconnect coolant by-pass hose. Remove exhaust heat shield. Disconnect exhaust crossover pipe at manifold. Remove exhaust manifold and gasket.

Removal (Cutlass Supreme, Grand Prix, Lumina & Regal)

1. Remove air cleaner assembly. Disconnect negative battery cable. Remove serpentine drive belt. Remove A/C compressor with hoses attached, and lay aside.
2. Remove right engine-to-body torque strut rod. Remove A/C and torque strut bracket from engine. Remove heat shield. Disconnect exhaust crossover pipe from manifold. Disconnect exhaust downpipe from manifold. Remove exhaust manifold and gasket.

Installation (All Models)

Reverse removal procedure using new gasket. Tighten exhaust manifold bolts to 18 ft. lbs. (24 N.m).

Removal (Beretta, Corsica, Cutlass Supreme, Grand Prix, Lumina & Regal)

1. Remove air cleaner assembly. Disconnect negative battery cable. Raise and support vehicle. Disconnect exhaust pipe from manifold. Lower vehicle.
2. On Cutlass Supreme, remove engine-to-body torque strut rod. Rotate engine to allow working space.
3. On all models, remove exhaust heat shield. Disconnect exhaust crossover pipe from manifold. Disconnect control cables and bracket from throttle body and upper intake manifold. Disconnect oxygen sensor connector. Remove exhaust manifold and gasket.

1. Disconnect negative battery cable. Remove throttle body air duct. Disconnect EGR transfer tube from upper intake manifold. Remove EGR valve adapter, EGR valve and heat shield from exhaust manifold.
2. Remove serpentine drive belt, air pump pulley and air pump upper bracket. Disconnect air injection hose from check valve. Raise and support vehicle. Disconnect exhaust crossover pipe from manifold.
3. Disconnect vacuum hose and electrical connector from air injection diverter valve. Lower vehicle. Remove air pump. Remove air injection pipe from manifold. Remove alternator bracket. Remove exhaust manifold and gasket.

1. Disconnect negative battery cable. Raise and support vehicle. Remove exhaust heat shield. Disconnect exhaust downpipe from manifold. Lower vehicle.
2. Disconnect exhaust crossover pipe from manifold. Remove EGR pipe. Disconnect oxygen sensor connector. Remove exhaust manifold and gasket.

To install, reverse removal procedure using new gasket. On all models except Camaro and Firebird, tighten exhaust manifold bolts to 18 ft. lbs. (24 N.m). On Camaro and Firebird, tighten exhaust manifold bolts to 25 ft. lbs. (34 N.m).

Removal (Beretta, Cavalier, Corsica & Sunbird)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Drain cooling system. Remove valve covers. Remove intake manifold. See INTAKE MANIFOLD under REMOVAL & INSTALLATION.
2. Remove exhaust crossover pipe. Remove left exhaust manifold. See EXHAUST MANIFOLD (LEFT) under REMOVAL & INSTALLATION. Remove oil dipstick tube (if necessary). Remove spark plug wires from left cylinder head. Remove push rods. Intake push rods are 6" long and marked orange and exhaust push rods are 6 3/8" long and marked blue. Remove cylinder head bolts, head and gasket.

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Remove intake manifold. See INTAKE MANIFOLD under REMOVAL & INSTALLATION. Raise and support vehicle.
2. Drain cooling system. Remove oil filter. Lower vehicle. Remove oil dipstick tube and bracket. Remove left exhaust manifold. See EXHAUST MANIFOLD (LEFT) under REMOVAL & INSTALLATION.
3. Remove serpentine belt. Remove A/C compressor and bracket, and lay aside. Remove engine lift bracket. Remove engine ground wire from rear of cylinder head. Remove power steering pump and bracket, and lay aside. Remove push rods. Remove cylinder head bolts, head and gasket.

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Remove intake manifold and gasket. See INTAKE MANIFOLD under REMOVAL & INSTALLATION.
2. Remove exhaust crossover pipe. Raise and support vehicle. Remove oil filter and adapter. Position oil cooler aside (if equipped). Lower vehicle. Remove A/C compressor, and lay aside.
3. Remove radiator hose from water pump. Remove engine strut mounting bracket bolts and bracket. Remove left side spark plug wires. Remove left exhaust manifold. See EXHAUST MANIFOLD (LEFT) under REMOVAL & INSTALLATION. Remove pipe nut. Remove cylinder head bolts, head and gasket.

Inspection (All Models)

Measure cylinder head surface warpage. Machine surface if warpage exceeds .005" (.13 mm). DO NOT remove more than .010" (.25 mm) of material from original surface.

Note. The intake push rods are 6 inches long and are marked orange, exhaust push rods are 6 3/8 inches long and are marked blue.

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.
2. Install cylinder head. Apply GM Sealant (1052080) to head bolt threads, and install bolts. Tighten cylinder head bolts in sequence to 33 ft. lbs. (45 N.m). (Scheme 4) Tighten bolts in sequence an additional 90 degrees using Cylinder Head Bolt Wrench (J-36660).
3. To complete installation, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS. Fill cooling system.

Scheme 4

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Remove air cleaner assembly. Disconnect negative battery cable. Drain cooling system. Raise and support vehicle.
2. Remove exhaust pipe at crossover. Lower vehicle. Remove exhaust crossover heat shield. Remove exhaust crossover at right exhaust manifold. Remove right exhaust manifold. See EXHAUST MANIFOLD (RIGHT) under REMOVAL & INSTALLATION.
3. Remove spark plug wires at right cylinder head. Remove valve cover. Remove intake manifold. See INTAKE MANIFOLD under REMOVAL & INSTALLATION. Remove push rods. Intake push rods are 6" long and are marked orange. Exhaust push rods are 6 3/8" long and are marked blue. Remove cylinder head bolts, head and gasket.

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Remove intake manifold. See INTAKE MANIFOLD under REMOVAL & INSTALLATION. Remove spark plug wires from right cylinder head.
2. Remove right exhaust manifold. See EXHAUST MANIFOLD (RIGHT) under REMOVAL & INSTALLATION. Raise and support vehicle. Drain cooling system. Drain crankcase oil.
3. Remove oil filter. Lower vehicle. Remove serpentine belt. Remove push rods. Remove belt tensioner. Remove alternator and brackets. Remove engine ground wire from rear of cylinder head. Remove cylinder head bolts, head and gasket.

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Drain cooling system. Remove right exhaust manifold. See EXHAUST MANIFOLD (RIGHT) under REMOVAL & INSTALLATION.
2. Remove valve covers. Remove intake manifold. See INTAKE MANIFOLD under REMOVAL & INSTALLATION. Remove push rods. Intake push rods are 6" long and are marked orange. Exhaust push rods are 6 3/8" long and are marked blue. Remove cylinder head bolts, head and gasket.

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Remove intake manifold and gasket. See INTAKE MANIFOLD under REMOVAL & INSTALLATION.
2. Raise and support vehicle. Remove exhaust pipe at rear exhaust manifold. Lower vehicle. Remove exhaust crossover pipe nuts to right exhaust manifold. Rotate engine forward. Disconnect oxygen sensor connector. Remove cylinder head bolts, head and gasket.

Measure cylinder head surface warpage. Machine surface if warpage exceeds .005" (.13 mm). DO NOT remove more than .010" (.25 mm) of material from original surface.

Note. The intake push rods are 6 inches long and are marked orange, exhaust push rods are 6 3/8 inches long and are marked blue.

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.
2. Install cylinder head. Apply GM Sealant (1052080) to head bolt threads, and install bolts. Tighten cylinder head bolts in sequence to 33 ft. lbs. (45 N.m). (Scheme 4) Tighten bolts in sequence an additional 90 degrees using Cylinder Head Bolt Wrench (J-36660).
3. To complete installation, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS table at end of article. Fill cooling system.

1. Disconnect negative battery cable. Drain cooling system. Remove coolant reservoir. Remove belt tensioner and serpentine belt. Remove power steering pump, and lay aside. Raise and support vehicle. Remove inner splash shield.
2. Remove flywheel cover. Remove crankshaft balancer. Remove serpentine belt idler pulley. Remove oil pan. See OIL PAN under REMOVAL & INSTALLATION. Remove lower front cover bolts. Lower vehicle.
3. Remove radiator hose at water pump. Remove by-pass pipe at front cover. Remove canister purge hose. Remove upper front cover bolts, and remove front cover.

1. Disconnect negative battery cable. Drain cooling system. Raise and support vehicle. Remove oil pan. See OIL PAN under REMOVAL & INSTALLATION. Lower vehicle.
2. Remove power steering pump and bracket, and lay aside. Remove water pump. Remove crankshaft damper. Disconnect lower radiator hose at front cover. Remove front cover bolts and cover.

1. Disconnect negative battery cable. Drain cooling system. Remove serpentine belt. Remove belt tensioner and alternator. Remove power steering pump, and lay aside.
2. Raise and support vehicle. Remove inner splash shield. Remove flywheel cover and starter. Remove crankshaft balancer and serpentine belt idler pulley. Remove oil pan. See OIL PAN under REMOVAL & INSTALLATION.
3. Remove lower front cover bolts. Lower vehicle. Remove radiator hose at water pump. Remove heater hose at cooling system fill pipe. Remove by-pass and overflow hoses. Remove water pump pulley. Remove spark plug wire shield at water pump. Remove canister purge hose. Remove upper front cover bolts and cover.

1. Remove air cleaner. Disconnect negative battery cable. Drain cooling system. Remove belt tensioner and alternator. Remove power steering pump, and lay aside.
2. Remove radiator hose at water pump. Remove heater hose at thermostat by-pass pipe. Remove thermostat by-pass pipe from front cover. Remove crankshaft balancer.
3. Raise and support vehicle. Remove starter. Remove oil pan. See OIL PAN under REMOVAL & INSTALLATION. Lower vehicle. Remove front cover bolts and cover.

Apply RTV sealant to sealing surface of front cover. Install new front cover oil seal. See FRONT COVER OIL SEAL. To install remaining components, reverse removal procedure.

1. Disconnect negative battery cable. Remove serpentine drive belt and crankshaft pulley. Remove flexplate/flywheel cover.
2. Prevent crankshaft from turning, and remove crankshaft damper bolt. Remove crankshaft damper using puller. Remove crankshaft damper key. Pry seal from front timing case cover.

Removal (Except Camaro & Firebird)

1. Remove air cleaner. Disconnect negative battery cable. Remove serpentine drive belt. Raise and support vehicle. Remove right front wheel and inner fender splash shield. Remove drive belt pulley.
2. Remove flexplate/flywheel cover. Prevent crankshaft from turning, and remove crankshaft damper bolt. Remove crankshaft damper using puller. Remove crankshaft damper key. Pry seal from front timing case cover.

1. Lubricate seal with engine oil. Install seal with open end of seal toward engine using Seal Installer(J-35468). Apply RTV sealant to keyway in crankshaft and crankshaft damper.
2. Install crankshaft damper using Damper Installer (J-29113). Ensure damper installer threads are at least .20" (5.1 mm) into crankshaft. To install remaining components, reverse removal procedure.

Removal

Remove engine front cover. See FRONT COVER under REMOVAL & INSTALLATION. Place No. 1 piston at TDC with marks of camshaft and crankshaft sprockets aligned. (Scheme 5) Remove camshaft sprocket bolts. Remove camshaft sprocket and timing chain. Using Crankshaft Sprocket Remover (J-5825-A), remove crankshaft sprocket.

Note. If camshaft sprocket does not come off easily, a light blow on lower edge of sprocket using a plastic mallet should dislodge camshaft sprocket.

1. Install crankshaft sprocket (if removed). Apply assembly lube to camshaft sprocket thrust face. Install timing chain over camshaft sprocket. Hold sprocket vertically with chain hanging down. Align timing marks. (Scheme 5)
2. Install timing chain and camshaft sprocket on camshaft. Ensure sprocket dowel pin hole aligns with camshaft dowel pin. Install camshaft sprocket. Ensure timing marks are aligned. Lubricate timing chain with engine oil.
3. Apply Sealant (1052917) or RTV sealant to sealing surfaces of front timing case cover. Install front timing case cover and new gasket. If crankshaft seal is removed, lubricate new seal with engine oil, and install with open side of seal toward engine using Seal Installer(J-35468-A).
4. Apply sealant to crankshaft and crankshaft damper keyways. Install crankshaft damper using Damper Installer (J-29113). Ensure damper installer threads extend at least.20" (5.1 mm) into crankshaft.
5. To install remaining components, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS table at end of article.

Scheme 5

CAMSHAFT

Note. To remove and install camshaft, remove engine from vehicle.

1. Remove engine. See ENGINE under REMOVAL & INSTALLATION. Remove intake manifold. See INTAKE MANIFOLD under REMOVAL & INSTALLATION. NOTE: Mark locations of rocker arm components, push rods and valve lifters for installation reference.
2. Remove rocker arms, push rods and valve lifters. Mark component locations for installation reference. Remove crankcase front cover. See FRONT COVER under REMOVAL & INSTALLATION.
3. Remove timing chain and camshaft sprocket. See TIMING CHAIN under REMOVAL & INSTALLATION. Remove camshaft. Remove camshaft bearings if necessary.

Inspection

Inspect camshaft journal diameter, lobe lift and oil clearance. See CAMSHAFT table under ENGINE SPECIFICATIONS at end of article. Replace components if not within specification.

1. Install camshaft bearings (if removed). Ensure oil holes are aligned. Lubricate camshaft bearings and lobes with engine oil. If camshaft is replaced, coat lobes with Engine Oil Supplement (1052367) or equivalent.
2. Install camshaft. To complete installation, reverse removal procedure. Ensure timing marks are aligned. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS.

1. Remove transaxle or transmission. See appropriate TRANSMISSION REMOVAL & INSTALLATION article in TRANSMISSION SERVICING (A/T models) or appropriate article in CLUTCHES (M/T models).
2. On M/T models, mark clutch pressure plate and flywheel for installation reference. Remove pressure plate, clutch disc and flywheel.
3. On A/T models, remove flexplate. On all models, pry seal from housing. Use care not to damage crankshaft at sealing surface. 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 6)
2. Align seal installer dowel pin with alignment hole of crankshaft. Install seal installer on crankshaft. To install seal in seal bore, tighten seal installer handle until seal installer collar is even with cylinder block.
3. To install remaining components, reverse removal procedure. On M/T models, ensure reference marks are aligned on pressure plate and flywheel.

Scheme 6

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

Apply thread sealant to water pump bolts. Install water pump using new gasket. Ensure locator tab on top of water pump housing is positioned vertically. To install remaining components, reverse removal procedure. Fill cooling system.

COOLANT REFILL PROCEDURES

Note. Used ethylene glycol must be disposed of in accordance w/Federal, State, and Local Laws. Check w/these laws before disposing this substance.

1. Park vehicle on a level surface. WARNING: To avoid being burned, do not remove the radiator cap while the engine is at normal operating temperature. The cooling system will release scalding fluid and steam under pressure if the cap is removed while the engine and radiator are still hot.
2. When the engine is cool remove radiator cap by Slowly rotating counterclockwise to detent. (Do not press down while rotating.) Wait until any residual pressure (indicated by a hissing sound) is relieved. After all hissing stops, press down on the cap while continuing to rotate counterclockwise.
3. Open the radiator drain valve located at the bottom of the left-hand radiator end tank.
4. Open the air bleed vents(s). Open the air bleed vents on the thermostat housing and the throttle body return pipe above the coolant pump. They should be opened on two to three turns. (Scheme 7)
5. Disconnect the negative cable from the battery.
6. Remove both engine block drains. The front engine block drain is located between the starter and engine oil filter. Refer to Fig. (Scheme 8). The rear engine block drain is located by the engine crank sensor.
7. Allow the system to drain completely. Inspect the drained coolant. If the coolant is discolored, flush the cooling system using steps 8, 9, 10, and 11. If the coolant appearance is normal proceed to step 12.
8. Close the radiator drain valve. Reinstall all engine block drains. Fill the cooling system through the radiator neck w/clean water until the level of the water is at the base of the radiator neck. Install the radiator cap.
9. Close all air bleed vents opened in step 4.
10. Reconnect the negative cable to the battery. NOTE: Block drive wheels, place transaxle in PARK or NEUTRAL and set the parking brake.
11. Run the engine until the thermostat open; Coolant Temp. approximately 93°-200°F. Stop the engine, drain, and refill the system as described in steps 1)-10) and see the WARNING between steps 1) and 2). Repeat this process a sufficient number of times until the liquid drained is nearly colorless.
12. Close the radiator drain vale tightly. Reinstall all block drains removed in step 6.
13. Remove the coolant recovery reservoir and empty. Flush the reservoir with clean water, drain and reinstall. NOTE: Use Ethylene Glycol coolant meeting GM specification 1825-M to provide the required freezing and corrosion protection at least 50 percent solution -37°C (-PT34°F).
14. Slowly fill the cooling system through the radiator neck using the following procedure: NOTE: If the cooling system has been flushed, first add 100 percent ethylene glycol in the amount listed. See «COOLANT CAPACITIES»(/buick/regal/iii-1988-1997/remont/mechanical/#31l-v6-vin-t) table. Then slowly add clean water to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait for two minutes and recheck the level of the coolant mixture, add clean water if necessary to restore the coolant mixture level to the base of the radiator neck. NOTE: If the cooling system is being refilled only (no flush), a 50/50 percent solution of ethylene glycol and clean water mixture should be used to fill the system. Fill the system until the level of the 50/50 mixture has reached the base of the radiator neck. Wait two minutes and recheck the level of the coolant mixture, add a 50/50 ethylene glycol/water coolant mixture if necessary to restore the coolant mixture level to the base of the radiator neck. COOLANT CAPACITIES Engine Type Amount of Ethylene Glycol (Coolant) 3.1L (LHO) 5.1L (171.1 oz.)
15. Install radiator cap making certain the arrows line up w/the overflow tube.
16. Close all air bleeds opened in step 4. Do not over-torque the air bleed valve. The air bleed valve is made out of the brass.
17. Fill the coolant reservoir with a 50 percent ethylene glycol and a 50 percent clean water coolant mixture. Add 1.7L (1.8 qts.) of a 50/50 mixture of ethylene glycol and clean water to the coolant recover reservoir.

Note. The low coolant indicator lamp may come on after this procedure. After operating the vehicle so that the engine heats up and cools down three times, if the low coolant indicator lamp does not go out, or fails to come on at ignition check and coolant is at the level indicated in step 1 . See TROUBLE SHOOTING CHART C-12 in the ENGINE COOLING FANS article in the ENGINE COOLING Section. If at any time the "TEMP" warning indicator comes on, immediate action is required.

Inspect

The freeze protection of the engine coolant after the engine heats up and cools down three times using a refractometer or a thermohydrometer to ensure proper freeze (-37°C (34°F)) protection. Obtain the coolant mixture for the inspection from the base of the radiator neck, not from the coolant recovery reservoir.

Scheme 7

Scheme 8

Raise and support vehicle. Drain crankcase oil. Remove oil filter, starter and flexplate/flywheel cover. Remove oil pan nuts and bolts. Remove oil pan and gasket.

1. Disconnect negative battery cable. Raise and support vehicle. Remove catalytic converter hanger bolts. Disconnect transmission fluid cooler lines from oil pan clips. Rotate crankshaft until timing mark on crankshaft damper is at 7 o'clock position as viewed from timing chain end of engine.
2. Drain crankcase oil. Remove torque converter dust cover (A/T models). Disconnect exhaust crossover pipe from manifolds. Remove engine mount through bolts. Raise and support engine. Remove oil pan nuts and bolts. Remove oil pan and gasket.

1. Disconnect negative battery cable. Remove serpentine drive belt and tensioner. Support engine from top using Engine Support (J-28467-A) Raise and support vehicle. Drain crankcase oil. Remove plastic and metal shields from starter area.
2. Remove starter with wires connected, and hang aside. Remove engine-to-frame mounting nuts. Remove right wheel and inner fender splash shield. Remove oil pan nuts and bolts. Remove oil pan and gasket.

1. Disconnect negative battery cable. Remove air cleaner assembly. Remove serpentine drive belt and tensioner. Support engine from top using Engine Support (J-28467-A) and Adapter Leg (J-36462).
2. Raise and support vehicle. Drain crankcase oil. Remove right wheel and splash shield. Remove steering gear pinch bolt. Remove transaxle mount nuts. Remove engine mount nuts. Remove front engine mount bracket from cylinder block.
3. Remove plastic and metal shields from starter area. Remove starter with wires connected, and hang aside. Place support under center of front frame crossmember. Loosen rear crossmember frame bolts (DO NOT remove).
4. Remove front frame bolts. Lower front frame. Remove oil pan nuts and bolts. Remove oil pan and gasket.

1. If rear oil pan seal is removed from bottom of main bearing, apply RTV sealant to tabs of seal, and install seal. Install oil pan using new gasket.
2. Tighten 2 rear oil pan bolts to 18 ft. lbs. (24 N.m). Tighten all other oil pan bolts and nuts to 89 INCH lbs. (10 N.m). To install remaining components, reverse removal procedure. Fill crankcase.

CYLINDER HEAD OVERHAUL

Measure cylinder head warpage at deck surface. Resurface cylinder head if warpage exceeds .005" (.13 mm). DO NOT remove more than .010" (.25 mm) of material from original surface of cylinder head.

VALVE SPRINGS

Measure valve spring free length, out-of-square, pressure and installed height (installed height measurement procedure is not available from manufacturer). See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS. Replace spring if not within specification.

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

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

VALVE SEAT

Measure seat runout and width. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. Machine or replace valve seat as necessary if it is not within specification. Valve seat replacement procedure is not available from manufacturer.

VALVES

Measure valve stem-to-guide oil clearance. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. If valve margin is not within specification, machine or replace valve. If valve stem-to-guide oil clearance is not within specification, replace valve with oversize valve. New valves must not be lapped. Protective coating will be damaged if valve is lapped.

VALVE SEAT CORRECTION ANGLES

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

CYLINDER BLOCK ASSEMBLY OVERHAUL

PISTON & ROD ASSEMBLY

Mark piston according to cylinder number for installation to 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 center of bore. Measure piston diameter at 90-degree angle to piston pin bore and 3/4" below center line of piston pin bore. Measure taper in 2 places: at center line of piston pin bore and near bottom of piston skirt (both at 90-degree angle to piston pin bore).
2. If piston clearance is not within specification, machine cylinder bore and install oversize piston as necessary. DO NOT machine oversize piston to fit cylinder bore or engine balance will be affected. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS.

PISTON RINGS

1. Measure piston ring end gap and side clearance. If end gap and side clearance are not within specification, replace piston rings and/or piston as necessary. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS.
2. Install piston rings with identification mark on ring land facing top of piston. Properly position ring end gaps around circumference of piston. (Scheme 9)

Scheme 9

ROD BEARINGS

Measure rod bearing oil clearance. If oil clearance is not within specification, regrind 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, regrind 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 at end of article. if not within specification, replace bearing and/or repair or replace crankshaft.

CYLINDER BLOCK

Measure deck surface warpage. Machine surface if warpage exceeds .005" (.13 mm). 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 .025 O.S. on cylinder block near lifter bore to indicate .001" (.025 mm) oversize lifters have been installed.

ENGINE OILING 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 10) 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 thrust face. Pressure regulator valve is mounted in oil pump body.

Scheme 10

CRANKCASE CAPACITY

Engine oil capacity is approximately 4 qts. (3.7L) without filter change. More oil may need to be added when replacing oil filter.

OIL PRESSURE

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

Removal & Disassembly

1. Remove oil pan. See OIL PAN under REMOVAL & INSTALLATION. Remove oil pump bolt, oil pump and extension shaft from rear main bearing cap.
2. To remove oil pump drive unit, remove bolt from top of drive unit and pull drive unit from top of engine. (Scheme 10)
3. 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. WARNING: On some models, pressure regulator valve spring is under pressure. Use care when removing to prevent personal injury.
4. Mark idler gear in relation to drive gear for reassembly reference. Remove gears from pump body. Remove pressure regulator valve retaining plug (or cotter pin on some models). 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 pump assembly if not within specification. See «OIL PUMP SPECIFICATIONS»(/buick/regal/iii-1988-1997/remont/mechanical/#31l-v6-vin-t) table.

OIL PUMP SPECIFICATIONS

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

Reassembly & Installation

1. To reassemble, coat all components with engine oil. Reverse disassembly procedure using new pump cover gasket. Align reference marks on gears.
2. If installing new pick-up tube, apply Sealant (1050026) to pick-up tube before installing into pump cover. On models using pressure regulator valve plug, coat plug threads with thread sealant.
3. To install, reverse removal procedure. Ensure pump extension shaft is fully engaged. Tighten oil pump mounting bolt to 30 ft. lbs.(41 N.m).

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

GENERAL SPECIFICATIONS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS SPECIFICATIONS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CONNECTING RODS SPECIFICATIONS

CONNECTING RODS

PISTONS, PINS & RINGS SPECIFICATIONS

PISTONS, PINS & RINGS

CYLINDER BLOCK SPECIFICATIONS

CYLINDER BLOCK

VALVES & VALVE SPRINGS SPECIFICATIONS

VALVES & VALVE SPRINGS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD

CAMSHAFT SPECIFICATIONS

CAMSHAFT

See also:
• TORQUE SPECIFICATIONS
• COOLANT CAPACITIES