3.0L V6 Mazda MPV V

ENGINE IDENTIFICATION

Note. To identify engine, see A - INTRODUCTION article in the ENGINE PERFORMANCE section.

Engine code is located on left, front side of cylinder block, below distributor.

ENGINE IDENTIFICATION CODES

Removal (MPV)

1. Release fuel pressure by starting engine and disconnecting airflow meter connector. After engine dies, turn ignition off.
2. Remove hood and battery. Remove starter and transmission. Drain engine oil and coolant. Remove engine undercover.
3. Remove radiator hoses. Remove cooling fan and fan shroud. Remove transmission cooling lines (if equipped). Remove radiator.
4. Remove drive belts and air cleaner assembly. Remove accelerator cable and heater hoses. Mark and remove vacuum hoses from engine. Remove canister and fuel hoses, making sure to cover fuel hoses with shop towel to stop residual pressure spray.
5. Remove alternator and bracket. Remove power steering pump pulley and pump with hoses connected and tie aside. (Scheme 13) Remove A/C compressor with hoses connected and tie aside. Remove plastic protective cover from top right front of engine. Disconnect engine wiring harness and ground wires.
6. Remove A/C hose bracket from center of firewall. Remove shroud upper panel from right side of firewall. Disconnect exhaust pipe.
7. Remove lower grille and radiator grille. Remove radiator shroud upper plate. Remove engine mount nuts and engine.

Installation (MPV)

To install, reverse removal procedure. Adjust tension of all drive belts. Reconnect fuel pump relay. Restore all fluids to proper level. Reconnect airlfow meter connector. See TORQUE SPECIFICATIONS .

Scheme 13

Scheme 14

1. Apply parking brake and block rear wheels. Start engine and disconnect fuel pump relay. (Scheme 14) Allow engine to stall. Turn ignition off. Reconnect fuel pump relay.
2. Disconnect negative battery cable. Remove hood. Raise and support front of vehicle. Drain engine oil and coolant. Remove fresh air duct, air cleaner and air intake tube. Disconnect accelerator cable.
3. Remove cooling fan and fan shroud. Remove water pump drive belt. Remove spark plug cables and spark plugs. Remove canister and power brake vacuum hoses.
4. Remove fuel hoses from pressure regulator, making sure to cover hose fitting with rag to prevent fuel spray. Plug disconnected hoses to prevent fuel leakage.
5. Disconnect heater hoses from engine. Disconnect engine wiring harness. Remove engine undercover and radiator hoses. Disconnect automatic transmission cooling lines from radiator (if equipped).
6. Remove radiator wiring harness and radiator. Remove alternator and adjusting bracket. Remove A/C compressor and power steering pump and tie aside with hoses still connected.
7. Remove exhaust pipe. Remove driveshaft and transmission. Remove engine mount nuts and remove engine. (Scheme 15)

Scheme 15

Installation (929)

To install, reverse removal procedure. Adjust tension of all drive belts. See BELT TENSION ADJUSTMENT table. Restore all fluids to proper level.

Removal

1. Apply parking brake and block rear wheels. Bleed fuel pressure as described in step 1) of appropriate ENGINE under ENGINE, MANIFOLDS & CYLINDER HEAD.
2. Disconnect negative battery cable. Remove fresh air duct, air cleaner and air intake tube. Disconnect accelerator cable. Remove canister and power brake vacuum hoses.
3. Remove fuel hoses from pressure regulator, making sure to cover hose fitting with rag to prevent fuel spray. Plug disconnected hoses to prevent fuel leakage.
4. Remove automatic transmission vacuum hose (if equipped). Remove 3-way solenoid valve assembly. Disconnect engine wiring harness connectors and grounds. Remove transmission dip stick tube (if equipped).
5. Remove distributor and EGR pipe. Remove 6 extension manifolds between upper and lower intake manifolds. Remove intake manifold, loosening bolts in 2 or 3 steps, in REVERSE order of tightening sequence. (Scheme 16)

Scheme 16

Installation

Using new gaskets and "O" rings, install intake manifold assembly. Tighten bolts using 2 steps in sequence. (Scheme 16) See TORQUE SPECIFICATIONS. Ensure all electrical and vacuum lines are properly connected. To complete installation, reverse removal procedure.

Removal & Installation

Remove exhaust crossover heat shield and crossover pipe. Remove exhaust manifold heat shields and exhaust manifolds. To install, use new gaskets and reverse removal procedure. See TORQUE SPECIFICATIONS .

Scheme 17

1. Apply parking brake and block rear wheels. Bleed fuel pressure as described in step 1) of appropriate ENGINE under ENGINE, MANIFOLDS & CYLINDER HEAD.
2. Disconnect negative battery cable. Drain engine coolant. Remove air intake hose. Disconnect accelerator cable from throttle body. Remove spark plug cables and spark plugs.
3. Remove cooling fan and fan shroud. Remove water pump drive belt. Remove A/C idler pulley. Remove crankshaft pulley and baffle plate. Remove coolant bypass and upper radiator hose.
4. Remove timing belt cover and gasket. Turn crankshaft to align match marks of pulleys. (Scheme 17) Remove upper timing belt idler pulley. Remove timing belt and timing belt automatic tensioner. Mark timing belt rotation if belt is to be reused.
5. Remove canister and power brake vacuum hoses. Remove fuel hoses from pressure regulator, making sure to cover hose fitting with rag to prevent fuel spray. Plug disconnected hoses to prevent fuel leakage.
6. Remove automatic transmission vacuum hose (if equipped). Remove 3-way solenoid valve assembly. Disconnect engine wiring harness connectors and grounds. Remove transmission dipstick tube (if equipped).
7. Remove distributor and EGR pipe. Remove 6 extension manifolds between upper and lower intake manifolds. Remove intake manifold, loosening bolts in 2 or 3 steps, in REVERSE order of tightening sequence. (Scheme 16)
8. Remove cylinder head covers. Remove exhaust crossover heat shield and crossover pipe. Remove exhaust manifold heat shields and exhaust manifolds. Remove front intake valley seal plate. Loosen cylinder head bolts in 2 or 3 steps in REVERSE order of tightening sequence. (Scheme 18)

Scheme 18

1. Ensure all mating surfaces are clean. Check cylinder block and cylinder head surfaces for warpage. See «ENGINE SPECIFICATIONS»(/mazda/mpv/v-1986-1991/remont/mechanical/#30l-v6). Resurface or replace as required.
2. Ensure cylinder head oil control plugs are installed in block. Measure oil control plug projection from cylinder block. Projection should be.21-.22" (5.3-5.7 mm). Apply engine oil to new "O" rings and install on oil control plugs.
3. Using new gaskets, install cylinder heads to block. New head gaskets are marked "L" for left bank and "R" for right bank. If re-using cylinder head bolts, measure each bolt. Intake side bolts should measure 4.25-4.29" (108-109 mm) and exhaust side bolts should measure 5.43-5.47" (138-139 mm). If bolts exceed maximum length, replace bolts.
4. Install and tighten cylinder head bolts in 2 steps and in sequence. (Scheme 18) First step is to tighten to 14 ft. lbs. (20 N.m). Second, tighten all bolts in sequence an additional 90 degrees. Third, tighten all bolts in sequence an additional 90 degrees. To complete installation, reverse removal procedure.

1. Disconnect negative battery cable. Drain engine coolant. Remove spark plug wires and spark plugs. Remove air intake hose. Remove cooling fan and fan shroud.
2. Remove drive belts. Remove A/C idler pulley. Remove crankshaft pulley and baffle plate. Remove coolant bypass and upper radiator hoses.
3. Remove timing belt cover and gasket. Turn crankshaft to align match marks of pulleys. (Scheme 17) Remove upper timing belt idler pulley. Remove timing belt and timing belt automatic tensioner. Mark timing belt rotation if belt is reused.

Inspection

Check automatic tensioner rod projection. Rod should project .47-.55" (12-14 mm) from tensioner body. Replace tensioner if projection is not to specification.

1. Place automatic tensioner in vise or arbor press, using a flat washer to prevent damage to tensioner body plug. Compress tensioner rod until a pin can be inserted into tensioner rod through hole in tensioner body. Install tensioner with pin installed. NOTE: Do not exceed 2200 lbs. (1000 kg) pressure on tensioner rod.
2. Ensure match marks on pulleys are still in alignment with marks on heads. (Scheme 17) With upper idler pulley removed, install timing belt on pulleys, keeping slack toward automatic tensioner side. Install upper idler pulley.
3. Rotate crankshaft twice in direction of rotation and ensure match marks are still in alignment. Remove pin from automatic tensioner and repeat steps to confirm match marks are still in alignment.
4. Check timing belt deflection between right cam pulley and lower idler. Deflection should be.20-.28" at 22 lbs. (5-7 mm at 10 kg.). If deflection is not correct, repeat installation procedure. If deflection is still not correct, check for failure of automatic tensioner or stretched timing belt. Reverse removal procedure to complete installation. See «TORQUE SPECIFICATIONS»(/mazda/mpv/v-1986-1991/remont/mechanical/#30l-v6__torque-specifications).

Scheme 19

1. Disconnect negative battery cable. Set timing marks on TDC and remove distributor. Loosen alternator belt. Remove timing belt covers and gaskets. Remove timing belt.
2. Remove valve covers. Loosen rocker shaft bolts in 2 or 3 steps in sequence. (Scheme 19) Remove rocker arm and shaft assemblies together with bolts.
3. Remove radiator and radiator upper shroud upper plate (if required). Remove camshaft pulley bolts and pulleys. Remove camshaft oil seals. Note camshaft end play before removing camshaft. Remove thrust plates and camshafts.

1. Inspect camshaft, journals and cam surface for wear or damage. Check runout with camshaft in "V" blocks, using dial indicator. Using total indicator reading, maximum runout limit is .001" (.03 mm). See «ENGINE SPECIFICATIONS»(/mazda/mpv/v-1986-1991/remont/mechanical/#30l-v6) .
2. Check camshaft lobe height and minimum lobe height. Replace camshaft if beyond limits. With thrust plates installed, measure end play with dial indicator. If end play exceeds maximum specification, replace thrust plate or camshaft as required.

1. Carefully install camshafts in heads. Install camshaft thrust plates. Align camshafts with Woodruff keys at 12:00 position. Install camshaft pulleys with "L" (left bank) and "R" (right bank) at 12:00 position.
2. Install rocker arm shaft assemblies by tightening bolts in 2 or 3 steps in reverse of bolt removal sequence. (Scheme 19) Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/mazda/mpv/v-1986-1991/remont/mechanical/#30l-v6__torque-specifications). Reverse removal procedure to complete installation.

VALVES

Inspect valves for roughness or damage to stems, stem tips or face. If thickness is less than specification, replace valve. See ENGINE SPECIFICATIONS. Valve stem end surface grinding limit is .020" (.50 mm). Inspect valve stem keeper grooves for excessive wear. Replace valves as necessary.

VALVE ARRANGEMENT

Intake Manifold Side: All intake valves.

Exhaust Manifold Side: All exhaust valves.

Remove valve covers. Loosen rocker shaft bolts in 2 or 3 steps in sequence. (Scheme 19) Remove rocker arm and shaft assemblies together with bolts.

Check for wear or damage to shaft contact surfaces and rocker arms. Check oil clearance between rocker arm and shaft. See ROCKER ARM SHAFT SPECIFICATIONS table. Replace if necessary.

ROCKER ARM SHAFT SPECIFICATIONS

Apply engine oil to bearing surface of rocker arms and shaft. To install, reverse removal procedure. Tighten bolts in 2 or 3 steps in REVERSE of removal sequence. (Scheme 19) See TORQUE SPECIFICATIONS.

Note. The intake side rocker arm shaft has twice as many oil holes as exhaust side. Also, ensure rocker arm shaft spring does not catch between shaft and mounting boss during installation.

Check valve springs for squareness and free length measurement. See ENGINE SPECIFICATIONS . Replace spring if not to specification.

Note. Outer valve spring has an uneven pitch design. Install spring with narrow pitch toward cylinder head.

VALVE GUIDES

Note. Although intake and exhaust valve guides are shaped differently, use exhaust valve guide as a replacement on both sides.

Using guide remover and hammer, tap guide from cylinder head from combustion chamber side.

Measure clearance between valve stem and guide. Insert valve in guide and move left or right. If tip moves more than specification, replace guide. See ENGINE SPECIFICATIONS .

Tap service guide into cylinder head. Guide should extend from spring side of cylinder head lower step approximately .520-.543" (13.24-13.81 mm) on intake guides and .772-.795" (19.64-20.22 mm) on exhaust guides. Measurement is taken from inner valve spring seat surface of cylinder head. See ENGINE SPECIFICATIONS . Regrind valve seat, to restore compatibility with new valve guide.

VALVE STEM INSTALLED HEIGHT

Measure protruding length of each valve stem. See ENGINE SPECIFICATIONS. If length is within service limit, use valve spring shims to bring measurement within acceptable limit. If length is greater than service limit, replace valve or cylinder head.

VALVE STEM INSTALLED HEIGHT

VALVE CLEARANCE ADJUSTMENTS

Note. Valve clearance is not adjustable, though some valve noise may occur if engine has not been operated for an extended period of time. The noise should disappear after the engine reaches normal operating temperature. If noise persists, check oil pressure, level and condition.

Remove valve cover. Check movement of Hydraulic Lash Adjuster (HLA) by pushing down each rocker by hand. If the rocker moves down, replace HLA.

Note. Do not remove HLA unless necessary. "O" ring can be damaged during removal.

Remove valve cover and rocker arm shaft assembly. HLA can be removed by hand or, if this is difficult, with pliers.

Install new "O" ring on HLA. Coat rocker arm oil reservoir and HLA with engine oil. Install HLA into rocker arm, ensuring "O" ring is not damaged.

1. Remove cylinder heads and oil pan. Remove oil screen, oil pump and oil pump drive shaft.
2. Remove any ridge from top of cylinder bore. Mark connecting rod and cap for cylinder identification. Remove rod cap. Push piston and rod assembly out top of cylinder block. Install cap on rod from which removed.

Scheme 20

1. Lubricate piston, rings and cylinder bore with engine oil. Install piston rings and properly space ring end gaps on piston. (Scheme 20) Install piston and rod into cylinder bore.
2. Ensure "L" (left bank) and "R" (right bank) marks on pistons face toward front (timing belt side of engine). Install and tighten rod cap nuts in 2 steps. First step is to 22 ft. lbs. (29 N.m), second step is to tighten nuts an additional 90 degrees.

FITTING PISTONS

1. Measure cylinder bore at 3 places for out-of-round and taper. If either out-of-round or taper exceeds .0007" (.019 mm), rebore cylinder for oversize pistons.
2. Insert piston in cylinder. Using a feeler gauge, determine piston-to-cylinder bore clearance. Clearance should be .0019-.0026" (.049-.065 mm). Maximum clearance is .0059" (.15 mm). If clearance exceeds maximum, rebore cylinder and install oversize piston.

CYLINDER BORE DIAMETERS (1)

PISTON DIAMETERS (1)

FITTING RINGS

1. Measure piston ring end gap. Use head of piston to push ring squarely into bore. Leave ring at bottom of ring travel. Using a feeler gauge, measure piston ring end gap. Compare measurement with specification. See «ENGINE SPECIFICATIONS»(/mazda/mpv/v-1986-1991/remont/mechanical/#30l-v6).
2. Install rings on piston. Note 2nd compression ring inner edge is slightly chamfered. Using a feeler gauge, measure ring side clearance between ring and ring land. If ring lands are excessively worn, replace piston.
3. Properly space ring end gaps on piston. (Scheme 20) Ensure end gaps do not align with piston pin or thrust face of piston. Install rings with manufacturer's mark facing up.

PISTON PINS

1. Using press and adapters, remove pin from piston and rod. Check pin and bores for signs of sticking, excessive wear or damage. Measure pin bore diameter in piston. Standard pin bore is .9050-.9055" (22.988-23.000 mm). Measure outside diameter of pin. Standard pin diameter is .9045-.9047" (22.974-22.980 mm).
2. Determine pin-to-piston clearance. Standard clearance is .0003-.0010" (.008-.026 mm). If wear exceeds specification, replace piston and/or pin. Pin must fit into piston with light thumb pressure at room temperature.
3. Piston pin is press fitted in rod. Align connecting rod cap mating mark with single valve recess side of piston. Standard interference fit of piston pin-to-rod is .0005-.0015" (.013-.037 mm).

1. Remove cylinder heads. Remove crankshaft timing belt pulley. Remove clutch (if equipped) and flywheel. Remove engine-to-transmission end plate.
2. Remove oil pan. Remove oil screen, oil pump and oil pump drive shaft. Remove front and rear crankshaft oil seal covers. Remove piston and rod assemblies. Remove main bearing caps. Remove crankshaft.

1. Check crankshaft main journals and connecting rod journals for scoring, wear or cracks. Taper and out-of-round of journals must not exceed .002" (.05 mm). Check crankshaft for runout by placing on "V" blocks.
2. Set dial indicator pointer at center main journal of crankshaft. If runout exceeds .0016" (.04 mm), replace crankshaft. Measure crankshaft journals to determine main bearing and rod bearing clearances.
3. Crankshaft main bearing journals should measure 2.4385-2.4392" (61.937-61.955 mm). Connecting rod journals should measure 2.0842-2.0848" (52.940-52.955 mm).
4. Use Plastigage method to determine oil clearance. Standard main bearing clearance is .0010-.0015" (.025-.037 mm). Maximum main bearing clearance is .0031" (.080 mm). If oil clearance exceeds specification, grind crankshaft and use undersize main bearings.

1. Install main bearing halves into engine block. Ensure bearings are on correct journal and oil feed holes are clear. Journal No. 4 requires thrust bearing. Upper bearing halves have oil grooves and are not interchangeable with lower bearing halves. Apply oil to main bearing surface. Install crankshaft.
2. Install main bearing caps and tighten in 3 steps. Start at center bearing and work outward. (Scheme 21) First step is to 14 ft. lbs. (20 N.m). Second step is to tighten all bolts an additional 90 degrees. Third step is tighten all bolts an additional 45 degrees. To complete installation, reverse removal procedure.

Scheme 21

CONNECTING ROD BEARINGS

1. Remove connecting rod caps and bearings. Clean connecting rod journal and bearing half with a clean shop towel. Check connecting rod bearing oil clearance using Plastigage method.
2. Standard connecting rod bearing oil clearance is .0009-.0025" (.023-.064 mm). Maximum connecting rod bearing oil clearance is .0039" (.10 mm). If oil clearance exceeds maximum, grind crankshaft and use undersize bearings.

CRANKSHAFT END PLAY

Check crankshaft end play with dial indicator. End play limit is .0118" (.30 mm). If end play exceeds specification, grind crankshaft and install oversize thrust bearing.

Remove front and rear crankshaft oil seal covers and remove oil seals. Apply engine oil to front cover and new front oil seal. Use suitable pipe or socket to install front seal. Coat rear cover, new oil seal and rear oil seal lip with engine oil. Using hammer, gently tap rear oil seal into rear cover.

ENGINE OILING SYSTEM

A positive displacement gear-type oil pump draws oil from oil pan and delivers it under pressure to main and connecting rod bearings. An oil hole in each connecting rod lubricates thrust side of piston and cylinder wall. An oil passage carries oil to camshaft and rocker arms. Oil spray lubricates valve stems.

CRANKCASE CAPACITY

Crankcase capacity is 4.8 qts. (4.5L) without oil filter replacement and 5.0 qts. (4.7L) when replacing oil filter. Capacity is 5.7 qts. (5.4L) after engine disassembly.

OIL PRESSURE

Note. Two different oil pumps are used on 3.0L engine. See OIL PUMP under ENGINE OILING for descriptions.

OIL PRESSURE SPECIFICATIONS

PRESSURE RELIEF VALVE

The pressure relief valve is externally accessible on "Trochoid" oil pumps, which are mounted within front engine cover. The pressure relief valve is mounted in cover of positive displacement pump and is non-adjustable.

Disconnect negative battery cable. Raise vehicle. Drain engine oil. Remove engine splash guard. Remove oil pan mounting bolts and oil pan. Insert a wide-face gasket scraper between oil pan and cylinder block to separate them. Remove oil pan. To install, reverse removal procedure.

OIL PUMP

Note. Two different oil pumps are used on the 929: A "Trochoid Gear," mounted within the front engine cover, or a "Positive Displacement," mounted on bottom of cylinder block. The MPV uses only the "Trochoid" pump.

Removal (Positive Displacement Pump)

Remove oil pan. See OIL PAN under ENGINE OILING. Remove oil pump and screen. Remove oil pump driveshaft and "O" ring. To complete installation, reverse removal procedure.

Inspection (Positive Displacement Pump)

1. Place oil pump screen in oil and turn driveshaft gear counterclockwise. Ensure oil is forced through discharge hole. Plug discard hole and ensure driveshaft gear cannot be turned.
2. Check oil pump gear-to-pump body clearance is .0028-.0043" (.07-.11 mm). Maximum clearance is .0059" (.15 mm).

Installation (Positive Displacement Pump)

Install new "O" ring on oil pump body. Install drive shaft and check for smooth operation. To complete installation, reverse removal procedure. See POSITIVE DISPLACEMENT OIL PUMP TORQUE SPECIFICATIONS table.

POSITIVE DISPLACEMENT OIL PUMP TORQUE SPECIFICATIONS

Scheme 22

Removal (Trochoid Pump)

1. Disconnect negative battery cable. Drain engine oil and coolant. Remove timing belt cover and gasket. Turn crankshaft to align match marks of pulleys. (Scheme 17)
2. Remove upper timing belt idler pulley. Remove timing belt and timing belt automatic tensioner. Mark timing belt rotation if belt is reused. Remove crankshaft pulley and timing belt drive pulley.
3. Remove thermostat housing. Remove oil pan and oil screen. Remove oil pump/front engine cover assembly.

Inspection (Trochoid Pump)

1. Remove pump cover screws and cover. (Scheme 22) Check oil pump body, plunger and plunger spring for damage or distortion. Check side clearance. Side clearance should be.0014-.0037" (.035-.096 mm) with a maximum of.0051" (.13 mm).
2. Check tooth tip clearance. Clearance should be.0016-.0079" (.04-.20 mm) with a maximum of.0064" (.24 mm).
3. Check outer rotor-to-pump body clearance. Clearance should be.0039-.0077" (.100-.196 mm) with a maximum of.0091" (.23 mm).

Installation (Trochoid Pump)

Apply engine oil to pump body and outside of seal before installing new seal. Replace coolant inlet pipe gasket. To install, reverse removal procedure. Tighten oil pressure relief valve plug to 28-45 ft. lbs. (38-61 N.m). See TORQUE SPECIFICATIONS .

Belt Tension Adjustment

See BELT TENSION ADJUSTMENTS table.

BELT TENSION ADJUSTMENTS

Coolant Capacity

Coolant capacity for MPV is 7.9 quarts (7.5L) including heater core. Coolant capacity for 929 with automatic transmission is 9.9 quarts (9.4L) including heater core. Coolant capacity for 929 with manual transmission is 9.5 quarts (9.0L) including heater core.

Radiator Pressure Cap

Radiator cap on both MPV and 929 should open at system pressure of 11-15 psi (0.75-1.05 kg/cm 2 ).

Thermostat

Thermostat opening temperature is 179-184°F (81.5-84.5°C). Thermostat should be fully open at 205°F (96°C).

Remove timing belt. See TIMING BELT . Remove water pump and gasket. To install, reverse removal procedure.

Note. For further information on cooling systems, see appropriate ENGINE COOLING article.

GENERAL ENGINE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECS

CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECS

CONNECTING ROD SPECIFICATIONS

CONNECTING ROD SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS

VALVE SPECIFICATIONS

VALVE SPECIFICATIONS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

CYLINDER BLOCK SPECIFICATIONS

CYLINDER BLOCK SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TORQUE SPECIFICATIONS
• BELT TENSION ADJUSTMENT
• OIL PUMP