3.0l v6 - VIN [3] Dodge Caravan II

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 eighth character of Vehicle Identification Number (VIN). The VIN is stamped on a plate on top of instrument panel at lower left of windshield.

ENGINE IDENTIFICATION CODES

VALVE CLEARANCE ADJUSTMENT

Hydraulic lash adjusters are used. No valve adjustment is required.

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.

1. Loosen fuel tank cap to release pressure. Disconnect injector wiring harness from engine wiring harness. Connect jumper wire from terminal No. 1 of injector harness to ground. (Scheme 28)
2. Connect a second jumper wire to terminal No. 2 of injector harness. Touch jumper wire to positive battery terminal for no more than 5 seconds to release fuel pressure. Remove jumper wires and reconnect wiring harness.

Scheme 28

ENGINE

Note. Remove engine with transaxle remaining in the vehicle.

Removal

1. Release fuel pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect battery. Scribe hood hinge location on hood for reassembly. Remove hood. Drain cooling system and engine oil. Disconnect necessary coolant hoses, control cables, fuel lines, electrical connections and vacuum hoses.
2. Remove air cleaner and radiator/fan assembly. Raise and support vehicle. Remove A/C compressor and power steering pump with hoses attached and set aside (if equipped).
3. Remove starter. Disconnect exhaust pipe at exhaust manifold. Remove torque converter cover. Reference mark flexplate to torque converter for reassembly reference.
4. Remove torque converter-to-flexplate bolts. Attach "C" clamp to bottom front edge of torque converter housing to secure torque converter.
5. Remove lower transaxle-to-cylinder block bolts. Lower vehicle. Support transaxle with floor jack. Attach lifting hoist to engine. Remove remaining transaxle-to-cylinder block bolts.
6. Place reference mark on side rail to indicate right insulator (timing belt side) position for reassembly reference. Remove right insulator-to-side rail bolts. CAUTION: To ensure proper positioning of the engine, right insulator position on side rail must be marked before removal for reassembly reference. Insulator must be installed in original position.
7. Remove through bolt from left engine mount from inside fenderwell. Insulator bracket-to-transaxle bolts may be removed instead of through bolt. Remove front engine mount bolts. Lift engine from vehicle.

Scheme 29

1. To install, reverse removal procedure. DO NOT tighten engine mount bolts until all bolts are installed. If vertical bolts on right or left mount were loosened, axle shaft length must be checked.
2. To determine axle shaft length, measure distance between inner edge of outboard boot and inner edge of inboard boot at 6 o'clock position. (Scheme 29)
3. Axle shaft length must be within specification. See AXLE SHAFT LENGTH SPECIFICATIONS table. AXLE SHAFT LENGTH SPECIFICATIONS Application In. (mm) Right Axle Shaft 20.5-20.9 (521-531) Left Axle Shaft 9.0-9.4 (229-239)
4. Adjust axle shaft length to specification by sliding engine in slots on engine mounts. Tighten all engine mount bolts once correct axle shaft length is obtained. CAUTION: Tighten vertical bolt in right mount bracket (timing belt side) before tightening through bolt.
5. Ensure reference mark is aligned on torque converter and flexplate. Tighten bolts to specification. See TORQUE SPECIFICATIONS table at end of article.

INTAKE MANIFOLD

1. Release fuel pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Drain cooling system. Remove air cleaner hose from throttle body. Remove throttle cable and transaxle kickdown linkage. Disconnect necessary electrical connections and vacuum hoses at throttle body and intake manifold.
2. Remove ignition coil from upper intake manifold. Wrap fuel lines with shop towel and disconnect from fuel rail. Remove retaining bolts, upper air intake and gaskets. (Scheme 30) Cover intake manifold openings with shop towel.
3. Disconnect vacuum hoses from fuel rail and pressure regulator. Disconnect fuel injector wiring harness from engine wiring harness. Remove retaining bolts and pressure regulator from fuel rail.
4. Remove retaining bolts and fuel rail assembly from intake manifold. Disconnect radiator and heater hoses. Remove retaining bolts, intake manifold and gaskets. (Scheme 30)

Scheme 30

Inspection

Inspect for clogged coolant passages in end crossovers. Check mounting surfaces for warpage. Ensure warpage does not exceed specification. See INTAKE MANIFOLD WARPAGE table.

INTAKE MANIFOLD WARPAGE

Scheme 31

1. Install gaskets and intake manifold. Tighten intake manifold nuts to specification in sequence. (Scheme 31) See TORQUE SPECIFICATIONS table at end of article.
2. Ensure injector holes are clean. Lubricate injector "O" rings with engine oil before installing. Install fuel rail and injectors until injectors are firmly seated in port. Install fuel rail retaining bolts. Install pressure regulator. Tighten bolts/nuts to specification. See TORQUE SPECIFICATIONS table at end of article.
3. Install upper air intake gaskets on intake manifold with beaded sealant side upward, away from intake manifold. Install upper air intake. Tighten upper air bolts in sequence to specification. (Scheme 32) See TORQUE SPECIFICATIONS table at end of article.
4. To install remaining components, reverse removal procedure. Fill cooling system.

Scheme 32

1. Raise and support vehicle. Disconnect exhaust pipe from rear exhaust manifold flange. Disconnect O2 sensor wiring. Remove exhaust crossover pipe mounting bolts. (Scheme 30) Remove rear exhaust manifold retaining nuts, and remove exhaust manifold.
2. Lower vehicle. Remove heat shield-to-front exhaust manifold bolts. Disconnect exhaust crossover pipe at front exhaust manifold. Remove retaining nuts and front exhaust manifold.

Check manifolds for cracks, damage and mounting surfaces for warpage. Repair or replace manifold if warpage exceeds .008" (.20 mm).

Installation

To install, reverse removal procedure. Install gasket with numbers 1-3-5 embossed toward the top, on rear exhaust manifold. Install gasket with numbers 2-4-6 embossed toward the top, on front exhaust manifold. Tighten bolts/nuts to specification. See TORQUE SPECIFICATIONS table at end of article.

1. Remove intake and exhaust manifolds. See INTAKE MANIFOLD and EXHAUST MANIFOLD under REMOVAL & INSTALLATION. Remove timing belt and camshaft sprockets. See TIMING BELT under REMOVAL & INSTALLATION. Remove distributor and adapter housing from cylinder head.
2. Remove rocker arm shaft assembly. See ROCKER ARM & LASH ADJUSTER under REMOVAL & INSTALLATION. Remove camshaft. Remove cylinder head bolts in sequence. (Scheme 33) Remove cylinder head and gasket.

Scheme 33

Check cylinder head for warpage. Resurface head if warpage exceeds specification. See CYLINDER HEAD table under ENGINE SPECIFICATIONS at end of article.

1. To install, reverse removal procedure. Ensure 10-mm Allen hex cylinder head bolts and washers are installed in correct location. (Scheme 33) Tighten cylinder head bolts to specification in sequence, using 2-3 steps. See TORQUE SPECIFICATIONS table at end of article.
2. Lubricate camshaft with engine oil before installing. To install remaining components, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS table at end of article.

Removal & Installation

1. Crankshaft front seal is located in oil pump housing. Timing belt and crankshaft sprocket must be removed for access to crankshaft front seal. Manufacturer does not indicate procedure for seal removal.
2. To install, apply light coat of engine oil on circumference of crankshaft front seal. Use Seal Installer (MB998306) to install crankshaft front seal.

1. Disconnect negative battery cable. Remove accessory drive belts. Remove A/C compressor with hoses attached, and secure aside. Remove A/C compressor mounting bracket and drive belt tensioner. Remove power steering/alternator belt tensioner. Remove power steering pump with hoses attached and secure aside.
2. Raise and support vehicle. Remove right inner fender shield. Remove crankshaft pulley and vibration damper. Lower vehicle and support engine with floor jack. Separate engine mount from engine mount bracket located in front of timing belt cover. Raise engine slightly. Remove engine mount bracket.
3. Remove timing belt covers, noting bolt length for reassembly reference. Rotate engine and align timing marks on front and rear camshaft sprockets and crankshaft sprocket. (Scheme 34) Mark direction of timing belt rotation for reassembly reference.
4. Loosen timing belt tensioner. Remove timing belt. Note direction of flange installation on front of crankshaft and remove (if necessary). If camshaft sprocket removal is required, use Camshaft Sprocket Holder (MB990775) to hold sprocket. Remove retaining bolt and camshaft sprocket.

Scheme 34

1. Install camshaft sprockets (if removed). Using camshaft sprocket holder, tighten camshaft sprocket retaining bolt to specification. See TORQUE SPECIFICATIONS table at end of article.
2. Ensure all timing marks are aligned. (Scheme 34) Rotate timing belt tensioner fully counterclockwise, and temporarily tighten retaining bolt. Install timing belt on crankshaft sprocket while holding belt tight on tension side. (Scheme 34) CAUTION: When installing timing belt, ensure it will turn in original direction.
3. Install timing belt on front (radiator side) camshaft sprocket. Install timing belt on water pump pulley, rear camshaft sprocket and then on timing belt tensioner.
4. Apply rotating force on front (radiator side) camshaft sprocket in opposite direction to apply pressure on tension side of timing belt. Ensure all timing marks align. (Scheme 34)
5. Install flange on front of crankshaft sprocket (if removed) with flat side against timing belt and offset side toward front of crankshaft. Loosen timing belt tensioner bolt, allowing spring tension to be applied on timing belt. Rotate crankshaft clockwise 2 full revolutions. CAUTION: Rotate crankshaft in a clockwise direction. DO NOT rotate crankshaft counterclockwise.
6. Realign all timing marks and tighten timing belt tensioner to specification. See TORQUE SPECIFICATIONS table at end of article. To install remaining components, reverse removal procedure. Ensure timing belt cover bolts are installed in original location. Tighten to specification. See TORQUE SPECIFICATIONS table at end of article.

ROCKER ARM & LASH ADJUSTER

Note. Lash adjuster operation should be checked before removing rocker arm.

1. Remove air cleaner assembly. Disconnect spark plug wires. Remove valve covers.
2. To check lash adjuster operation, insert a small wire through air bleed hole at top of rocker arm, directly above lash adjuster. Lightly push check ball downward in lash adjuster and check rocker arm for free play. If free play does not exist, replace lash adjuster.
3. Install Lash Adjuster Retainers (MD998443) on rocker arms. (Scheme 35) Loosen, but DO NOT remove, camshaft bearing cap bolts. Mark location of rocker arms for reassembly reference. Camshaft bearing caps are numbered for location. (Scheme 37) Remove rocker arms, shafts and camshaft bearing caps as an assembly.

Scheme 35

Scheme 36

Scheme 37

Scheme 38

1. Ensure rocker arm shaft for intake valves contains an additional oil feed hole in bottom of shaft. (Scheme 36)
2. Ensure No. 1 bearing cap is installed with machined portion of rocker arm shaft facing downward, toward cylinder head. This positions notch areas of rocker arm shafts upward, pointing toward outside of camshaft bearing cap. (Scheme 37)
3. Apply sealant on camshaft bearing cap-to-cylinder head mating surfaces at both ends of cylinder head. (Scheme 38) Install rocker arm shaft assembly. CAUTION: Arrow on camshaft bearing caps MUST face same direction as arrow on cylinder heads. (Scheme 38) Camshaft bearing caps must be properly installed, as camshaft bearing cap No. 2 contains oiling inlet hole from cylinder head. (Scheme 36)
4. Tighten camshaft bearing cap bolts to specification in 2 steps in the following order: No. 3, No. 2, No. 1 and then No. 4 camshaft bearing cap. See TORQUE SPECIFICATIONS table at end of article.
5. Install distributor adapter (if removed). Tighten bolts to specification. See TORQUE SPECIFICATIONS table at end of article. Coat camshaft oil seal lip with grease.
6. Thread Seal Installer (MD998713) into camshaft and install camshaft oil seal. Using Plug Installer (MD998306), install camshaft plug. Before installing valve cover, apply RTV sealant at front and rear camshaft bearing cap-to-valve cover gasket contact areas.
7. To install remaining components, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS table at end of article.

1. Remove distributor and distributor adapter (if necessary). Remove timing belt. See TIMING BELT under REMOVAL & INSTALLATION.
2. Remove rocker arm and lash adjuster. See ROCKER ARM & LASH ADJUSTER under REMOVAL & INSTALLATION. Remove camshaft and oil seals.

Inspect components for damage. Replace if damaged. Ensure all oil holes are not restricted. Inspect camshaft and cylinder head journal areas for damage. Inspect distributor drive gear for damage. Measure lobe height. Replace camshaft if not within specification. See CAMSHAFT table under ENGINE SPECIFICATIONS at end of article.

To install, reverse removal procedure. Lubricate camshaft with engine oil before installing.

REAR CRANKSHAFT OIL SEAL

Note. Rear crankshaft oil seal is a one-piece oil seal mounted in seal retainer. Manufacturer lists procedure with seal retainer removed from cylinder block.

1. Remove flywheel for access to seal retainer. Remove seal retainer. It may be necessary to remove oil pan, as oil pan seals against seal retainer. Remove oil seal from seal retainer.
2. Using Seal Installer (MD998718), install rear crankshaft oil seal into seal retainer. Before installing seal retainer, apply RTV sealant on seal retainer-to-cylinder block surface. Install seal retainer. To install remaining components, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS table at end of article.

1. Remove timing belt. See TIMING BELT under REMOVAL & INSTALLATION. Drain cooling system. Remove retaining bolts, water pump, gasket and "O" ring on coolant inlet pipe.
2. To install, reverse removal procedure. Install NEW "O" ring on coolant inlet pipe. Apply water to "O" ring before installing water pump. DO NOT apply grease to "O" ring. Tighten bolts to specification. SeeTORQUE SPECIFICATIONS table at end of article. To install remaining components, reverse removal procedure. Fill cooling system.

1. Removal procedure is not available from manufacturer. To install, apply a.12" (3.0 mm) diameter bead of RTV sealant around edge of oil pan before installing.
2. Ensure sealant is applied in sealing surface groove and on outside of bolt holes. DO NOT allow sealant to be forced from flange area toward flywheel.
3. Install oil pan. Tighten bolts to specification in sequence. (Scheme 39) See TORQUE SPECIFICATIONS table at end of article.

Scheme 39

Cylinder Head

Check cylinder head warpage. Resurface cylinder head if warpage exceeds specification. See CYLINDER HEAD table under ENGINE SPECIFICATIONS at end of article.

Valve Springs

Check valve spring free length, out-of-square and pressure. Replace valve spring if not within specifications. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS at end of article.

Valve Stem Oil Seals

Umbrella-type oil seals are used on all valves. Seals must be replaced if removed for any reason. When reinstalling valves, DO NOT overcompress valve springs, or valve stem oil seal may be damaged.

Valve Guides

Check valve guide I.D. and valve stem-to-valve guide oil clearance. Clearance must be within specification. See CYLINDER HEAD table under ENGINE SPECIFICATIONS at end of article. No service procedure is available from manufacturer.

Valve Seat

Check valve seat width. Grind valve seat if width is not within specification. See CYLINDER HEAD table under ENGINE SPECIFICATIONS at end of article.

Valves

Check margin and stem diameter. Replace valve if not within specifications. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS at end of article.

Valve Seat Correction Angles

Use a 15-degree stone to lower valve seat or a 65-degree stone to raise valve seat.

Rocker Arm Shaft Assembly

1. Note location and direction of rocker arm components and camshaft bearing caps. Remove camshaft bearing cap bolts. Disassemble rocker arm shaft assembly. (Scheme 36)
2. Ensure intake valve rocker arm shaft has a.12" (3 mm) oil hole in bottom of shaft. (Scheme 36) Exhaust valve rocker shaft does not have oil hole. Oil hole supplies oil to exhaust valve rocker arm shaft through camshaft bearing cap.
3. Inspect components for damage. Replace if damaged. Ensure all oil holes are not clogged. Reassemble rocker arm shaft assembly.

Lash Adjuster

Lash adjuster is located in rocker arm. Lash adjuster must not be disassembled.

Piston & Rod Assembly

For cylinders No. 1, 3 and 5, install pistons with "R" front mark on top of piston toward timing belt side of engine. For cylinders No. 2, 4 and 6, install piston with "L" front mark toward timing belt side of engine. Ensure front mark "72" on connecting rod is facing toward timing belt side of engine. (Scheme 40)

Scheme 40

Fitting Pistons

Measure cylinder bore diameter and taper at .50" (12.7 mm) below top surface of cylinder bore, middle of bore and .38" (9.6 mm) from bottom of cylinder bore. Measure piston diameter at .08" (2.0 mm) from bottom of piston skirt at right angle to piston pin. Piston diameter and clearance must be within specification. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS at end of article.

Piston Rings

Ensure ring end gap and side clearances are within specification. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS at end of article. Ensure piston ring end gaps are properly positioned. (Scheme 41)

Scheme 41

Rod Bearings

1. When replacing rod bearings, ensure front mark "72" on connecting rod faces toward timing belt side of engine. (Scheme 40)
2. Tighten connecting rod nuts to specification. See TORQUE SPECIFICATIONS table at end of article. Ensure bearing oil clearance and side play are within specifications. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS and CONNECTING RODS tables under ENGINE SPECIFICATIONS at end of article.

Crankshaft & Main Bearings

1. Upper main bearings contain oil grooves, while lower bearings installed in main bearing cap assembly do not.
2. Main bearing cap assembly must be installed with arrow toward front (timing belt end) of engine. Coat bolts with oil before installing. Tighten bolts to specification in sequence. (Scheme 42) See TORQUE SPECIFICATIONS table at end of article.
3. Ensure main bearing oil clearance and crankshaft end play are within specifications. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS at end of article. Replace thrust bearing if end play is not within specification.

Scheme 42

Thrust Bearing

1. Two types of thrust bearings are used, one with positioning tabs and another without. One set of thrust bearings (one with positioning tab and one without tab) fit in cylinder block, and another set in main bearing cap assembly at No. 3 main bearing.
2. Thrust bearing without positioning tab fits on front (timing belt side) of cylinder block and rear (flywheel side) of main bearing cap assembly. Thrust bearing with positioning tab fits on rear (flywheel side) of cylinder block and on front (timing belt side) of main bearing cap assembly. Groove side on thrust bearing goes toward crankshaft.
3. Replace thrust bearing if crankshaft end play is not within specification. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS at end of article.

Cylinder Block

1. Using a feeler gauge and straightedge, check cylinder block deck surface for warpage. Surface cylinder block if warpage exceeds specification. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS at end of article. CAUTION: DO NOT grind more than .008" (.20 mm) combined total from surface of cylinder head and deck surface of cylinder block.
2. Check cylinder bore, taper and out-of-round. Measurements should be taken at .50" (12.7 mm) below top surface of cylinder bore, middle of bore and .38" (9.6 mm) from bottom of cylinder bore. Bore cylinder block if not within specification. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS.

ENGINE OILING

A crankshaft-driven oil pump provides pressurized lubrication to main oil gallery. (Scheme 43)

Scheme 43

Crankcase Capacity

Oil capacity with oil filter is 4.5 qts. (4.2L).

Oil Pressure

Oil pressure is 30-100 psi (2.1-7.0 kg/cm 2 ) at 3000 RPM with engine at normal operating temperature.

Removal & Disassembly

1. Remove timing belt and crankshaft sprocket. See TIMING BELT under REMOVAL & INSTALLATION. Remove oil pan and pick-up tube.
2. Remove oil pump-to-cylinder block bolts. Note bolt location and length for reassembly. Remove oil pump. Disassemble oil pump. (Scheme 44) Remove oil seal from oil pump case.

1. Inspect components for damage. Measure clearance between small area of inner rotor and oil pump case. Measure clearance between outer rotor and oil pump case.
2. With inner and outer rotors installed in oil pump case, place straightedge across oil pump case and both rotors. Using feeler gauge, check rotor end clearance between rotors and straightedge. Ensure relief plunger slides freely in bore. Replace oil pump assembly if clearance exceeds specification. See OIL PUMP SPECIFICATIONS table.

OIL PUMP SPECIFICATIONS

Reassembly & Installation

1. To reassemble, reverse disassembly procedure. Ensure components are installed in original location. If oil seal was removed from oil pump case, use Seal Installer (MB998306) to install NEW seal. Lubricate seal lip with oil before installing.
2. To install, reverse removal procedure. Ensure bolts are installedin original location. (Scheme 44) Tighten bolts to specification. See TORQUE SPECIFICATIONS table at end of article.

Scheme 44

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS SPECS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS SPECS

CONNECTING RODS SPECIFICATIONS

CONNECTING RODS SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS

CYLINDER BLOCK SPECIFICATIONS

CYLINDER BLOCK SPECIFICATIONS

VALVES & VALVE SPRINGS SPECIFICATIONS

VALVES & VALVE SPRINGS SPECIFICATIONS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

See also:
• ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION