3.8L v6 - VIN [L] 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 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 code, located on cylinder block, may be required when ordering replacement parts. (Scheme 11) See ENGINE IDENTIFICATION CODES table.

ENGINE IDENTIFICATION CODES

Scheme 11

VALVE CLEARANCE ADJUSTMENT

No valve adjustment is required, as hydraulic valve lifters are used.

TROUBLE SHOOTING

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

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.

Removal

1. Remove hood. Release fuel pressure. See «FUEL PRESSURE RELEASE»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__fuel-pressure-release) . Remove battery cables. Drain cooling system and crankcase oil. Remove windshield washer, radiator and heater supply hoses. NOTE: Engine is lifted alone from engine compartment.
2. Disconnect all electrical harness connectors from engine. Remove drive belt. Remove power steering pump and set aside. Remove air-flow duct and air cleaner. Remove cables and hoses from throttle body. Remove ignition coil ground strap.
3. Disconnect fuel lines and vacuum hoses. Disconnect upper engine strut. Raise and support vehicle. Disconnect exhaust pipe. Disconnect engine mount bolts. Disconnect A/C compressor (if equipped) and set aside. Disconnect engine oil cooler lines (if equipped).
4. Remove lower transaxle-to-engine bolts. One bolt is located between transaxle case and engine block and is installed in opposite direction. Remove flexplate cover. Match mark flexplate to torque converter to ensure proper reassembly.
5. Remove flexplate-to-torque converter bolts. Disconnect engine support bracket at transaxle. Lower vehicle. Remove remaining transaxle-to-engine bolts. Remove engine.

Installation

1. To install, reverse removal procedure. Fill radiator to base of filler neck. Start engine. Place heater-A/C control in A/C mode and at highest temperature setting. Run engine to 3000 RPM and back to idle 5 times to expel any trapped air in system.
2. Refill radiator as necessary. Install radiator cap. Allow engine to cool. Check coolant level in reservoir. Add coolant as necessary to bring level to ADD or FULL COLD mark.

INTAKE MANIFOLD

Note. DO NOT disassemble upper intake manifold from lower intake manifold unless replacement of one of the components is necessary.

Note. This procedure removes the complete intake manifold assembly.

1. Release fuel pressure. See «FUEL PRESSURE RELEASE»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__fuel-pressure-release) . Disconnect negative battery cable. Remove plastic engine cover and air intake duct.
2. Remove spark plug wires and fuel rail. Remove exhaust crossover heat shield and power steering pump bracket. Remove alternator and bracket. Remove cable bracket, heater pipes and by-pass hose. Remove intake manifold bolts, manifold, gaskets and seals.

1. Ensure sealing surfaces and bolt threads and holes are clean. Apply GM Sealant (12345336) at the end of seals on cylinder block. Install manifold and gaskets. Coat bolt threads with thread sealant and install.
2. Tighten intake manifold bolts in sequence TWICE to 88 INCH lbs. (10 N.m). (Scheme 12) Lubricate coolant "O" rings with anti-freeze and fuel rail "O" rings with engine oil prior to installation. To install remaining components, reverse removal procedure. Fill cooling system.

Note. Apply thread sealant to intake manifold bolts prior to installation. Intake manifold bolts must be tightened in sequence TWICE to 88 INCH lbs. (10 N.m). (Scheme 12)

Scheme 12

INTAKE MANIFOLD (UPPER)

Note. Do not disassemble upper intake manifold from lower intake manifold unless replacement of one of the components is necessary.

1. Release fuel pressure. See «FUEL PRESSURE RELEASE»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__fuel-pressure-release) . Disconnect negative battery cable. Remove fuel injector sight shield and air intake duct. Remove spark plug wires on right side of engine and set aside.
2. Remove fuel rail. Remove exhaust heat shield and cable bracket to cylinder head mounting bolt. Remove upper intake manifold bolts, and manifold.

To complete installation, observe the following important tips, and reverse the removal procedures

1. Lower manifold intake ports should be plugged using clean shop towels before cleaning sealer off mating surface.
2. Mating surface should not be scraped, sanded or wire brushed in order to remove old sealer. Old sealer should be removed chemically by using any of the various chemical gasket removers available.
3. Apply a 1/16" bead of Loctite Instant Gasket Eliminator GM P/N (1052942) or equivalent to lower manifold mating surface. Make sure to circle all bolt holes.
4. Lower upper intake onto lower intake carefully.
5. Tighten upper manifold bolts to 11 Ft. Lbs. (15 N.m).
6. It is not necessary to replace the manifold should a stud or well-nut spin in the manifold. Studs or well-nuts can be retained from the back-side using a 15 mm wrench.
7. When reinstalling a throttle body, it is important that the retaining studs be coated with Loctite 242 or equivalent to prevent the nuts from vibrating loose.

Left/Front

1. Disconnect negative battery cable. It may be necessary to remove air inlet duct. Disconnect spark plug wires. Remove crossover pipe bolts from manifold.
2. Remove engine lift hook and manifold heat shield (if equipped). Remove oil dipstick and tube. Remove manifold bolts, manifold and gasket. To install, reverse removal procedure using new gasket.

Right/Rear

1. Disconnect negative battery cable. Disconnect spark plug wires and oxygen sensor. Remove EGR pipe (if equipped). It may be necessary to disconnect throttle cable from throttle body and brake booster hose. Disconnect cross-over pipe and exhaust pipe from manifold.
2. Remove transaxle dipstick. Remove manifold heat shield (if equipped). Remove catalytic converter heat shield and pipe hanger. Remove exhaust pipe-to-manifold nuts. Remove engine lift bracket, manifold bolts, manifold and gasket. To install, reverse removal procedure using new gasket.

1. Remove intake manifold. See «INTAKE MANIFOLD»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__intake-manifold) under REMOVAL & INSTALLATION. Remove exhaust manifold. See «EXHAUST MANIFOLD»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION.
2. On front cylinder head applications, disconnect spark plug wires. Remove engine lift bracket and valve cover. Remove exhaust crossover pipe and cooling fan. Remove alternator, ignition coil and bracket. Remove A/C compressor bracket bolt.
3. On rear cylinder head applications, disconnect spark plug wires. Remove exhaust crossover pipe. Remove power steering pump with hoses attached and lay aside. Remove heater pipe from front cover housing. Remove transaxle fill tube. Remove belt tensioner assembly and fuel line heat shield (if equipped).
4. Remove rocker arms, push rods and guide plates. See «ROCKER ARMS & PUSH RODS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION. Remove cylinder head bolts, cylinder head and gasket.

Inspection

Inspect cylinder head warpage. See CYLINDER HEAD OVERHAUL .

1. Ensure cylinder head bolt threads and cylinder block holes are clean. Ensure all holes align with cylinder block.
2. Install cylinder head. Apply GM Sealant (1052080) to head bolt threads and install. Tighten all bolts to 35 ft. lbs. (47 N.m) in proper sequence. (Scheme 13)
3. Tighten all bolts an additional 130 degrees in proper sequence. Tighten the center 4 bolts an additional 30 degrees in proper sequence.
4. To install remaining components, reverse removal procedure. Coat rocker arm bolts with GM Threadlock (12345493) prior to installation.

Scheme 13

1. Hold flywheel with J 37096. Remove balancer bolt. Install crankshaft puller J 38197 to puller to pulley and tighten puller bolt to remove pulley.

Note. The balancer is serviced as an assembly. Do not attempt to separate pulley from balancer hub.

1. Install crankshaft balancer. Lubricate seal surface with engine oil. Install balancer bolt. Hold flywheel with J37096. Install balancer bolt to 150 N.m + 76 degrees (111 lb.ft. + 76 degrees).

Disconnect negative battery cable. Remove serpentine belt. Raise and support vehicle. Remove right front wheel and inner splash shield. Remove crankshaft pulley/balancer bolt and crankshaft pulley/balancer. See CRANKSHAFT BALANCER . Pry seal from front timing case cover.

Using Seal Installer (J-35354) and crankshaft pulley/balancer bolt, install seal. Remove seal installer. Coat outside surface of crankshaft pulley/balancer and seal with oil prior to installation. To install remaining components, reverse removal procedure.

1. Disconnect negative battery cable. Drain cooling system. Remove serpentine belt. Disconnect heater pipes. Disconnect coolant hoses at case cover. Remove lower radiator hose.
2. Raise and support vehicle. Remove right front wheel and inner splash shield. Remove crankshaft pulley/balancer bolt and crankshaft pulley/balancer. Disconnect electrical connections at oil pressure sender, camshaft sensor and crankshaft sensor.
3. Remove oil pan-to-case cover bolts. Remove front timing case cover bolts, case cover and gasket. (Scheme 14)

Scheme 14

1. Inspect timing chain and sprockets for wear. Timing chain in and out movement should not exceed 1" (25.4 mm). Replace if necessary.
2. To install, reverse removal procedure using new gasket. Coat case cover bolts with thread sealant prior to installation. Crankshaft sensor must be adjusted.
3. With crankshaft sensor mounted loosely on mounting pedestal, install sensor and mounting pedestal on Crankshaft Sensor Adjuster (J-37089). (Scheme 15) Install crankshaft sensor adjuster and sensor assembly on crankshaft.
4. Install mounting pedestal-to-cylinder block bolts and tighten to 14-28 ft. lbs. (19-38 N.m). Install sensor-to-mounting pedestal bolts to 30-35 INCH lbs. (3.3-3.9 N.m).
5. Remove crankshaft sensor adjuster from crankshaft. Place sensor adjuster inside the crankshaft pulley/balancer. Rotate sensor adjuster. Replace crankshaft pulley/balancer if sensor adjuster contacts balancer at any point.
6. To install remaining components, reverse removal procedure. Coat outside surface of crankshaft pulley/balancer shaft and seal with oil prior to installation.

Scheme 15

1. Remove front timing case cover. See «FRONT TIMING CASE COVER»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION. Remove camshaft button and camshaft button spring. (Scheme 14)
2. Inspect timing chain and sprockets for wear. Timing chain in and out movement should not exceed 1" (25.4 mm). Replace if necessary.
3. Rotate crankshaft and align timing marks on camshaft and crankshaft sprockets. (Scheme 16) Remove timing chain damper assembly.
4. Remove camshaft sprocket bolts. Remove camshaft sprocket and timing chain. Remove crankshaft sprocket (if necessary).

Scheme 16

Note. If balance shaft has been moved, ensure alignment is correct. See BALANCE SHAFT under REMOVAL & INSTALLATION.

1. If engine has been rotated, rotate crankshaft so No. 1 cylinder is at TDC. Temporarily install camshaft sprocket. Rotate camshaft sprocket so timing mark is downward.
2. Remove camshaft sprocket and install timing chain on camshaft sprocket. Install timing chain and camshaft sprocket. Ensure timing marks are aligned. (Scheme 16) Install camshaft sprocket bolts. Install timing chain damper, camshaft button and camshaft button spring.
3. To install remaining components, reverse removal procedure. Ensure timing marks are aligned.

1. Disconnect negative battery cable. Remove serpentine belt. For left (front) valve cover removal, remove alternator bracket and spark plug wires.
2. For right (rear) valve cover removal, loosen power steering pump bolts and move pump forward with hoses still attached. Remove power steering pump brackets.
3. Remove EGR pipe, EGR valve and adapter from throttle body adapter.
4. Remove spark plug wires and valve cover. Remove rocker arm pivot bolts. Remove rocker arms and components. (Scheme 17) Mark component locations for reassembly reference.

Note. Mark location of all valve train components for reassembly reference. Components must be installed in original location.

To install, reverse removal procedure. Coat rocker arm bolts with GM Threadlock (12345493) prior to installation. Apply thread sealant to valve cover bolts prior to installation.

Scheme 17

1. Remove intake manifold. See «INTAKE MANIFOLD»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__intake-manifold) under REMOVAL & INSTALLATION. Remove rocker arms and push rods. See «ROCKER ARMS & PUSH RODS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION.
2. Remove push rod guide bolts and push rod guide. (Scheme 17) Remove valve lifter guide and valve lifters. Mark component locations for reassembly reference.

To install, reverse removal procedure. Apply Engine Oil Supplement (1052367) to valve lifters prior to installation. Ensure components are installed in original location.

1. Remove engine. See «ENGINE»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION. Remove intake manifold. See «INTAKE MANIFOLD»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__intake-manifold) under REMOVAL & INSTALLATION.
2. Remove rocker arms and push rods. See «ROCKER ARMS & PUSH RODS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION. Remove valve lifters. Remove timing chain and sprockets. See «TIMING CHAIN & SPROCKETS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION. Remove camshaft and bearings (if required).

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

Note. Lubricate camshaft bearings and camshaft lobes with GM Lubricant (1052365) prior to installation.

1. Install camshaft bearings (if removed). Ensure oil holes are aligned. Apply Sealant (1052914) to rear camshaft plug prior to installation. Lubricate camshaft bearings and camshaft lobes with GM Lubricant (1052365) prior to installation. Install camshaft.
2. To install remaining components, reverse removal procedure. Ensure components are installed in original location and all timing marks are aligned.

1. Disconnect negative battery cable. Remove engine. See «ENGINE»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION.
2. Remove flywheel. Remove intake manifold. See «INTAKE MANIFOLD»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__intake-manifold) under REMOVAL & INSTALLATION. Remove lifter guide retainer. (Scheme 17)
3. Remove front timing case cover. See «FRONT TIMING CASE COVER»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION. Remove balance shaft gear bolt. (Scheme 18) Remove camshaft sprocket and timing chain.
4. Remove bolts from balance shaft retainer. (Scheme 18) Remove balance shaft retainer and balance shaft gear. Install Slide Hammer (J-6125-B) in front of balance shaft and remove balance shaft. Remove balance shaft plug from rear of cylinder block.
5. Note direction of rear bearing installation. Using Rear Bearing Remover (J-36995-5), remove bearing from block. (Scheme 19)

Scheme 18

Scheme 19

Note. Balance shaft and bearings are serviced as complete assembly only. Proper installation tools must be used to prevent balance shaft damage.

Inspect components for damage. Measure bearing bore I.D. Replace components if not within specification. See BALANCE SHAFT SPECIFICATIONS table.

1. Lubricate balance shaft bearings with engine oil. Install rear bearing with rolled edge facing inward, toward engine, and manufacturer's marking facing flywheel side of engine. Using Rear Bearing Installer (J-36995-1), install rear bearing. (Scheme 19) NOTE: Install balance shaft rear bearing with rolled edge facing inward, toward engine, and manufacturer's marking facing flywheel side of engine.
2. Using Balance Shaft Installer (J-36996), install balance shaft. Temporarily install balance shaft retainer and bolts. Install balance shaft gear. Apply GM Threadlock (12345493) to gear retaining bolt, and install bolt. Tighten gear retaining bolt to specification. See «TORQUE SPECIFICATIONS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__torque-specifications) table at end of article.
3. Install balance shaft rear plug. Using dial indicator, measure balance shaft end play and radial clearance at front and rear of balance shaft. (Scheme 20) Replace components if not within specification. See «BALANCE SHAFT SPECIFICATIONS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) table.
4. Rotate camshaft so timing mark is downward when sprocket is installed. With camshaft sprocket and gear removed, rotate balance shaft so timing mark on gear is downward.
5. Align timing marks on camshaft gear and balance shaft gear by rotating balance shaft, and install camshaft gear. (Scheme 16) Rotate crankshaft so No. 1 piston is at TDC. Install timing chain and sprocket. Ensure timing marks are aligned. (Scheme 16)
6. Using dial indicator, measure gear lash at 4 places. Gear lash should be within specification. See «BALANCE SHAFT SPECIFICATIONS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) table. If all measurements are within specification, tighten balance shaft retainer bolts to specification. See «TORQUE SPECIFICATIONS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__torque-specifications) table at end of article. To install remaining components, reverse removal procedure.

BALANCE SHAFT SPECIFICATIONS

Scheme 20

1. For seal replacement, engine must be removed. See «ENGINE»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION. Remove flywheel. Confirm rear seal leak.
2. To remove seal, pry around dust lip using a screwdriver or similar tool. DO NOT damage crankshaft O.D. surface or chamfer. Ensure seal areas are clean.

1. Apply engine oil to new seal. Install seal using Seal Installer (J-38196). Align dowel pin of installer with dowel pin hole in crankshaft. Tighten installer attaching screws to 60 INCH lbs. (5 N.m).
2. Rotate handle of installer until collar is tight against case. Reverse removal procedure for remaining components.

Removal & Installation

1. Disconnect negative battery cable. Drain cooling system. Remove water pump drive belt. Disconnect necessary coolant hoses.
2. Remove water pump pulley bolts and pulley (access hole in body side rail for long bolt). Remove water pump bolts, water pump and gasket. To install, reverse removal procedure using new gasket. Fill cooling system.

1991 Models

1. Disconnect negative battery cable. Raise and support vehicle. Drain crankcase and remove oil filter. Remove flexplate access cover and crossover pipe (if equipped).
2. Disconnect engine mounts. Raise and support engine. Remove oil pan bolts and oil pan. To install, reverse removal procedure. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__torque-specifications) at end of this article.

1992 Models

1. Disconnect negative battery cable. Raise and support vehicle. Drain crankcase and remove oil filter. Remove right front wheel, lower flap and splash shield. Remove crankshaft pulley. Remove crank sensor cover.
2. Disconnect A/C compressor electrical connector. Remove A/C compressor and lay it aside. Remove hose support from suspension support (if equipped). Remove bolts at front of right suspension support.
3. Loosen all suspension support bolts to drop suspension supports about 1.5" (38 mm). Disconnect oil level sensor electrical connector. Remove flexplate access cover and crossover pipe (if equipped).
4. Disconnect engine mounts. Remove oil pan bolts and oil pan. To install, reverse removal procedure. Tighten to bolts to specification. See «TORQUE SPECIFICATIONS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__torque-specifications) at the end of this article.

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. 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. They should be opened on two to three turns.
5. Disconnect the negative cable from the battery.
6. Remove the engine block drains.
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° or 200°F. Stop the engine, drain, and refill the system as described in steps 1-10 and see the WARNING in 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: If the cooling system has been flushed, first add 100 percent ethylene glycol in the amount listed in the «COOLANT CAPACITIES TABLE»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) below for the appropriate engine application. 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. COOLANT CAPACITIES Engine Type Amount of Ethylene Glycol (Coolant) 3800 (L27) 5.25L (177.5 oz.) 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.
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. The proper amount of this mixture to be installed into coolant reservoir is listed below: 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 14). 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.

1. Inspect cylinder head for warpage at deck surface and manifold surfaces. Resurface cylinder head if warpage exceeds specification. See «CYLINDER HEAD»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) table in ENGINE SPECIFICATIONS at end of article.
2. Check amount of metal removed from cylinder head to determine if head can be used. To determine amount removed, use depth micrometer and measure the distance from deck surface to the 3 cast pads. (Scheme 21)
3. Measurement should be.054-.066" (1.37-1.68 mm) on new cylinder heads. Minimum dimension is.044" (1.12 mm). Replace cylinder head if measurement is less than minimum dimension.

Scheme 21

VALVE SEATS

No replacement procedure is given by manufacturer.

VALVE GUIDES

Valve guides must be reamed for an oversized valve if valve stem oil clearance is not within specification. See CYLINDER HEAD table in ENGINE SPECIFICATIONS at end of article.

SEAT CORRECTION ANGLES

After grinding, if seat width is too wide, a 20-degree or 70-degree stone can be used to reduce seat width. The 20-degree stone will lower the seat, and the 70-degree stone will raise the seat.

VALVE SPRING INSTALLED HEIGHT

1. Install valve, valve retainer and keepers. Pull upward on valve and measure height from top of spring seat to spring side of the valve retainer. (Scheme 22)
2. Spring installed height must be within specification. See «VALVES & VALVE SPRINGS»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) table in ENGINE SPECIFICATIONS at end of article. If measurement exceeds specification, add shims under the valve spring to obtain correct height.

Scheme 22

VALVE STEM HEIGHT

With valve installed in cylinder and in closed position, use steel ruler to measure distance from spring seat to the valve tip. Distance should be 1.935-1.975" (49.15-50.16 mm).

VALVE STEM OIL SEALS

Oversized valve stem oil seals are used for oversized valves. Intake and exhaust valve stem oil seals are different. Proper oil seal must be installed according to part number.

CYLINDER BLOCK

Using feeler gauge and straightedge, inspect deck surface for warpage. Replace cylinder block if more than .010" (.25 mm) material is removed from deck surface.

PISTON RING INSTALLATION

Install piston rings with identification mark toward top of piston and rings properly spaced. (Scheme 23)

Scheme 23

PISTON & ROD ASSEMBLY

Piston can be installed on connecting rod in either direction. Piston and connecting rod must be installed with 2 parallel ridges on bottom of pin boss toward front of engine.

FITTING PISTONS

Piston diameter should be measured 1.74" (44.2 mm) from the top of the piston.

Note. On all models, oversized pistons must not be machined down or engine balance will be affected.

CRANKSHAFT & MAIN BEARINGS

1. Rear crankshaft oil seal must be installed prior to crankshaft installation. See «REAR CRANKSHAFT OIL SEAL»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l) under REMOVAL & INSTALLATION.
2. To align crankshaft thrust surfaces, install all bearings and main caps and tighten all bolts evenly. Loosen all bolts one turn.
3. Retighten all bolts to 90 ft. lbs. (122 N.m). Using wooden mallet, carefully tap crankshaft forward then backward to align thrust bearing.

ROD BEARINGS

1. Ensure bearing cap bolt holes and mating surfaces are clean and dry. Use connecting rod stud protector on all rod cap bolts. Install inserts in connecting rod and cap. Lubricate bearings and crank pin.
2. Install bearing cap. Tighten rod bearing cap bolts to 20 ft. lbs. (27 N.m). Tighten bolts an additional 50 degrees using Torque Angle Meter (J-36660).

CYLINDER BLOCK FLANGE RUNOUT

1. With engine removed and crankshaft installed, measure cylinder block flange runout. Mount dial indicator gauge plate flat against crankshaft flange. Place dial indicator stem on lower left transmission bolt boss (flat area around bolt hole). Adjust dial indicator to zero.
2. Observe and record readings obtained on all bolt holes bosses. Measurement should not vary more than .010" (.25 mm). If readings exceed specifications, check crankshaft flange runout. See «CRANKSHAFT FLANGE RUNOUT»(/buick/regal/iii-1988-1997/remont/mechanical/#38l-v6-vin-l__crankshaft-flange-runout) under CYLINDER BLOCK ASSEMBLY.

CRANKSHAFT FLANGE RUNOUT

1. With engine removed and crankshaft installed, or with crankshaft mounted on V-blocks, measure crankshaft flange runout. Mount dial indicator and place dial indicator stem on crankshaft flange. Adjust dial indicator to zero.
2. Mark reference point on crankshaft flange. Ensure that crankshaft is thrust forward so end float will not affect readings. Turn crankshaft 360 degrees.
3. Observe and record readings. Reading should no vary more than .002" (.05 mm). Replace crankshaft if runout exceeds specification.

ENGINE OILING SYSTEM

The crankshaft driven gear-type oil pump provides pressurized lubrication to the main gallery. (Scheme 24) Oil pump and pressure regulator valve are located in the front timing case cover.

Scheme 24

CRANKCASE CAPACITY

Engine oil capacity is approximately 4 qts. (3.7L) with filter change. Recheck oil level after changing filter.

NORMAL OIL PRESSURE

Normal oil pressure is 60 psi (4.2 kg/cm 2 ) at 1850 RPM with 5W-30 engine oil and engine at normal operating temperature.

Remove front timing case cover. See FRONT TIMING CASE COVER under REMOVAL & INSTALLATION. Remove oil filter adapter, gasket, pressure regulator and valve from front timing case cover. Remove pump cover and gears from case cover.

1. Inspect components for damage. Measure gear end clearance. Measure housing gear pocket depth and diameter. Measure outer gear-to-housing clearance and tip clearance between gears.
2. 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/#38l-v6-vin-l) table.

Reassembly & Installation

To reassemble, reverse disassembly procedure. Lubricate all gears and fill cavities with petroleum jelly. Install pump cover. To install, reverse removal procedure. Tighten cover screws to 97 INCH lbs. (11 N.m). Tighten oil filter adapter bolts to 24 ft. lbs. (33 N.m).

OIL PUMP SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

GENERAL SPECIFICATIONS

BEARING SPECIFICATIONS

MAIN & CONNECTING ROD BEARINGS SPECS

CONNECTING ROD SPECIFICATIONS

CONNECTING ROD SPECIFICATIONS

PISTON/PIN/RING SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS (VIN L - L27)

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
• COMPUTER RELEARN PROCEDURES
• ENGINE IDENTIFICATION CODES
• FUEL PRESSURE RELEASE
• INTAKE MANIFOLD
• TORQUE SPECIFICATIONS
• CRANKSHAFT FLANGE RUNOUT