2.5L V6: Removal & Installation Mazda MX-6 I

REMOVAL & INSTALLATION

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.

Removal

1. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-49161-S38827827172001011500000) under REMOVAL & INSTALLATION. Disconnect negative battery cable. Drain cooling system, engine oil and transaxle fluid. Raise and support vehicle. Reference mark hood hinges and remove hood. Remove front wheels.
2. Remove lower engine covers. Remove air intake duct and air cleaner assembly. Remove battery and battery tray. Disconnect necessary control cables, electrical connections, coolant hoses, vacuum hoses and fuel lines. Disconnect electrical connector from electric cooling fan. Remove radiator with electric cooling fan. CAUTION: To disconnect heater hoses, press tabs inward on retainer on end of heater hose, then separate heater hoses at heater hose joint. DO NOT lose "O" rings and spacers located on heater hose joint.
3. Remove accessory drive belts. Remove retaining bolts and power steering reservoir with hoses attached, and secure reservoir aside. Disconnect heater hoses at bulkhead. Remove retaining nut and power steering pump pulley. Remove A/C compressor and power steering pump with hoses attached, and secure components aside. Remove cruise control actuator.
4. On M/T models, remove clutch release cylinder with hose attached, and secure cylinder aside. Disconnect shift rod and stabilizer rod at transaxle. On A/T models, disconnect shift control cable at transaxle.
5. On all models, disconnect electrical connections at transaxle. Remove front crossmember. Remove exhaust head pipe. Remove stabilizer bar links.
6. Separate tie rod ends from steering knuckles. Remove ball joint pinch bolts. Remove axle shaft support bearing bracket-to-cylinder block retaining bolts. Pry lower control arm downward and separate ball joint from steering knuckle.
7. Using bar inserted between axle shaft and transaxle, pry axle shafts from transaxle. Use care not to damage oil seal when removing axle shaft.
8. Remove through-bolt, retaining nuts and right (timing belt side) engine mount. Remove retaining bolts and nuts, and separate transaxle mount and bracket from transaxle and body. Support engine with hoist. Remove fore and aft engine mount nuts. Remove engine mount crossmember. Lift engine and transaxle from vehicle.

Installation

1. Install engine mount crossmember. Tighten retaining nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) . Install engine and transaxle.
2. Install engine mount-to-engine mount crossmember retaining nut, and tighten it to specification. Install right (timing belt side) engine mount, through-bolt and retaining nuts. Tighten through-bolt and retaining nuts to specification. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) .
3. Install transaxle mount and bracket. Tighten bracket retaining bolts and nuts to specification. Install NEW retaining ring on end of axle shaft. Coat axle shaft splines and sliding surfaces with grease. Install axle shafts in transaxle with opening of retaining ring facing upward.
4. Pull outward on axle shafts to ensure retaining ring is seated in transaxle. Install and tighten axle support bearing bracket evenly to specification.
5. To install remaining components, reverse removal procedure. Tighten fasteners to specs. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) . Fill engine with oil. Fill A/T transaxle with Dexron II ATF or M/T transaxle with SAE 75W-90 gear oil with API rating of GL-4 or GL-5.
6. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(ref-49161-S36555986632001011500000) under REMOVAL & INSTALLATION. Ensure accelerator cable has .06-.17" (1.5-4.5 mm) deflection at throttle body when installed. If deflection is not as specified, rotate nut on end of cable at throttle body until specified deflection is obtained.

1. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-49161-S38827827172001011500000) under REMOVAL & INSTALLATION. Drain cooling system.
2. Remove air intake duct, airflow meter and air cleaner assembly. Disconnect necessary control cables, electrical connections, coolant hoses, vacuum hoses and fuel lines.
3. Remove intake manifold support brace. Loosen intake manifold retaining bolts and nuts evenly using several steps. Remove intake manifold assembly and gaskets. (Scheme 12)
4. If removing fuel injectors, remove retaining bolts, fuel injector retainer, insulators, fuel injectors, fuel rail and pressure regulator, and fuel rail insulators (if necessary). (Scheme 12) Fuel rail insulators are located between fuel rail and intake manifold.

1. To install fuel injectors, install NEW "O" rings on fuel injector. Coat "O" rings with engine oil. Using twisting motion, install fuel injector in fuel rail so notch on side of fuel injector engages notch in fuel rail.
2. Install NEW insulators and "O" rings on fuel rail. Install and tighten retaining bolts to specs. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) . To install remaining components, reverse removal procedure. Install all intake manifold retaining bolts and nuts before tightening to specification. Tighten all fasteners evenly to specification.
3. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(ref-49161-S36555986632001011500000) under REMOVAL & INSTALLATION. Ensure accelerator cable has .06-.17" (1.5-4.5 mm) deflection, at throttle body when installed. If deflection is not as specified, rotate nut on end of cable at throttle body until specified deflection is obtained.

Scheme 12

1. Disconnect exhaust head pipe from exhaust manifold. Remove exhaust manifold heat insulator. Remove retaining bolts, nuts, exhaust manifold and gasket.
2. To install, reverse removal procedure using NEW exhaust manifold gasket. Tighten bolts and nuts to specification. See the «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) table.

1. Remove intake manifold. See «INTAKE MANIFOLD»(ref-49161-S04025736882001011500000) under REMOVAL & INSTALLATION. Remove retaining bolt and distributor (if necessary).
2. Remove retaining bolts, valve cover and gasket. Remove timing belt and camshaft sprocket. See «TIMING BELT»(ref-49161-S21845880902001011500000) under REMOVAL & INSTALLATION. Remove retaining bolts and seal plate from front of cylinder head. (Scheme 12)
3. Remove retaining bolts and coolant outlet. Remove exhaust manifold. See «EXHAUST MANIFOLD»(ref-49161-S08225026402001011500000) under REMOVAL & INSTALLATION. Remove camshafts. See «CAMSHAFT»(ref-49161-S03740297402001011500000) under REMOVAL & INSTALLATION. CAUTION: Cylinder head bolts must be loosened in proper sequence to prevent cylinder head warpage. (Scheme 13)
4. Loosen cylinder head bolts in sequence using several steps. (Scheme 13) Remove cylinder head bolts and washers, cylinder head and gasket.

Scheme 13

Scheme 14

1. Remove timing belt and crankshaft sprocket. See «TIMING BELT»(ref-49161-S21845880902001011500000) under REMOVAL & INSTALLATION. Using a knife, cut seal lip from the seal. Pry seal from oil pump body. DO NOT damage sealing surfaces.
2. To install, apply engine oil to seal lip of NEW seal. Install seal on crankshaft. Using hammer and pipe of suitable diameter, tap seal into oil pump body until seal surface is even with oil pump body. To install remaining components, reverse removal procedure.

Scheme 15

1. Disconnect negative battery cable. Remove lower engine covers. Remove accessory drive belts. Remove water pump pulley. Remove idler pulley bracket. (Scheme 15)
2. Remove retaining bolts and power steering reservoir with hoses attached, and secure reservoir aside.
3. Remove retaining nut and power steering pump pulley. Remove retaining bolts and power steering pump with hoses attached, and secure pump aside. Remove crankshaft pulley retaining bolt. Using puller, remove crankshaft pulley. CAUTION: DO NOT damage crank angle sensor rotor on rear of crankshaft pulley during crankshaft pulley removal.
4. Unplug crank angle sensor and unclip wires from oil dipstick tube. Remove oil dipstick and oil dipstick tube. Remove crank angle sensor harness bracket. Remove engine wiring harness, located along top of timing belt cover.
5. Support engine using hoist. Remove through-bolt, retaining nuts and right (timing belt side) engine mount. Remove retaining bolts, timing belt covers and gaskets. (Scheme 15)
6. Install crankshaft pulley retaining bolt in crankshaft. Rotate crankshaft so No. 1 cylinder is at TDC on compression stroke. Ensure groove on crankshaft sprocket aligns with indicator on oil pump body. (Scheme 16)
7. If reusing timing belt, place reference mark on timing belt to indicate direction of rotation. Hold timing belt tensioner and remove lower retaining bolt first, then remove upper bolt. Remove timing belt tensioner.
8. Remove No. 2 timing belt pulley and timing belt. Remove No. 1 idler pulley and tensioner pulley (if necessary). If removing camshaft sprocket, hold camshaft with wrench on hex area at center of camshaft. Remove retaining bolt and camshaft sprocket.
9. If removing crankshaft sprocket, use puller to remove crankshaft sprocket from crankshaft. Remove key from crankshaft (if necessary).

Scheme 16

1. Remove intake manifold. See «INTAKE MANIFOLD»(ref-49161-S04025736882001011500000) under REMOVAL & INSTALLATION. Remove retaining bolts, valve cover and gasket. Remove camshafts. See «CAMSHAFT»(ref-49161-S03740297402001011500000) under REMOVAL & INSTALLATION.
2. Note location of Hydraulic Lash Adjusters (HLA) for reassembly reference. Remove hydraulic lash adjusters from cylinder head.

Note. Store hydraulic lash adjusters in normal upright position submerged in clean engine oil.

Coat HLA and cylinder head surface with engine oil. Install HLA in original location. To install remaining components, reverse removal procedure.

Scheme 17

1. Remove intake manifold. See «INTAKE MANIFOLD»(ref-49161-S04025736882001011500000) under REMOVAL & INSTALLATION. Remove retaining bolts, valve cover and gasket. Remove timing belt and camshaft sprocket. See «TIMING BELT»(ref-49161-S21845880902001011500000) under REMOVAL & INSTALLATION.
2. Remove distributor (if necessary). Remove seal plate. (Scheme 12) Align dowel pin in camshaft with alignment mark to ensure no pressure exists on hydraulic lash adjusters. (Scheme 17)
3. Note location of camshaft bearing caps for reassembly reference. Camshaft bearing caps on right cylinder head are numbered for location with No. 1 at timing belt end of engine. Camshaft bearing caps on left cylinder head contain letters for location with "A" at timing belt end of engine. (Scheme 18)
4. Loosen front camshaft bearing cap bolts in sequence using several steps. (Scheme 18) Remove front camshaft bearing caps.
5. Loosen remaining camshaft bearing cap bolts in sequence using several steps. Remove all camshaft bearing caps except thrust bearing cap. Thrust bearing cap is removed last. CAUTION: Remove thrust camshaft bearing cap last to prevent damage to thrust caps. (Scheme 18)
6. Remove camshaft, oil seal and blind cap. (Scheme 12) Note location of hydraulic lash adjuster for reassembly reference. Remove hydraulic lash adjuster (if necessary). NOTE: Store valve lash adjusters in normal upright position submerged in clean engine oil.
7. Inspect friction gear on front of camshaft for damage (if equipped). If removing friction gear, install camshaft in soft-faced vise on hexagonal area of camshaft. Remove nut and friction gear.

Scheme 18

1. Disconnect negative battery cable. Remove transmission/transaxle and flywheel. For automatic or manual transmission removal procedure, see appropriate TRANSMISSION REMOVAL & INSTALLATION article in the TRANSMISSION/TRANSAXLE section. Pry out seal. «TRANSMISSION REMOVAL & INSTALLATION - A/T»(ref-49056) «TRANSMISSION REMOVAL & INSTALLATION - M/T»(ref-49162)
2. To install, apply light coat of oil to seal lip and push seal over crankshaft. Tap seal into rear cover until it is flush with edge of rear cover. DO NOT bottom seal in cover.
3. Completely remove used sealant from flywheel bolts. Apply lock-type sealant to bolts, and install flywheel to crankshaft. Tighten flywheel/flexplate bolts to 45-49 ft. lbs. (61-67 N.m) in a star-pattern sequence. Install clutch assembly (if equipped) and tighten cover bolts to 13-20 ft. lbs. (18-26 N.m) in a star-pattern sequence. Install transmission. See appropriate TRANSMISSION REMOVAL & INSTALLATION article in the TRANSMISSION/TRANSAXLE section. Pry out seal. «TRANSMISSION REMOVAL & INSTALLATION - A/T»(ref-49056) «TRANSMISSION REMOVAL & INSTALLATION - M/T»(ref-49162)

1. Disconnect negative battery cable. Drain cooling system. Remove timing belt. See «TIMING BELT»(ref-49161-S21845880902001011500000) under REMOVAL & INSTALLATION. Remove idler pulleys for timing belt (if necessary).
2. Remove engine mount bracket located above water pump on cylinder block. Remove retaining bolts, water pump and seal ring.

To install, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS . Fill and bleed cooling system. See COOLING SYSTEM BLEEDING under REMOVAL & INSTALLATION.

For removal and installation procedure (Scheme 19)

Scheme 19

For thermostat removal and installation (Scheme 20)and (Scheme 21).

Scheme 20

Scheme 21

1. Disconnect negative battery cable. Raise and support vehicle. Drain engine oil. Remove lower engine covers. Remove front crossmember. Remove exhaust head pipe.
2. Remove oil pan retaining bolts. Install a bolt into nut welded on oil pan flange at rear corner of oil pan. Slightly tighten bolt to separate oil pan from cylinder block. Remove oil pan. Remove retaining bolts, pick-up tube and gasket (if necessary).

1. Install gasket and pick-up tube (if removed). Tighten retaining bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) . Ensure sealing surfaces are clean. Apply bead of sealant on inside of bolt holes and at center of oil pan sealing surface, between bolt holes. CAUTION: Before installing oil pan bolts, ensure oil pan bolts and cylinder block bolt holes are free of sealant. Cylinder block may be crack if bolts are not cleaned before installation.
2. Install oil pan. Install bolts, and tighten them to specification. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) . To install remaining components, reverse removal procedure. Fill crankcase with oil.

Removal & Disassembly

1. Remove timing belt and crankshaft sprocket. See «TIMING BELT»(ref-49161-S21845880902001011500000) under REMOVAL & INSTALLATION. Remove oil pan. See «OIL PAN»(ref-49161-S23080300022001011500000) under REMOVAL & INSTALLATION.
2. Remove oil pump pick-up tube and baffle plate. Remove retaining bolts, oil pump and "O" ring. Remove oil pump body cover and oil pump components. (Scheme 22)

Scheme 22

Reassembly & Installation

1. To reassemble, coat rotors with engine oil. Install rotors in oil pump body. Ensure reference marks (dots) on rotors face the outside of oil pump body (toward oil pump cover).
2. Install oil pump body cover, and tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000). Install relief valve, spring, NEW gasket and relief valve plug. Tighten relief valve plug to specification.
3. Install crankshaft front seal (if removed) until seal surface is even with oil pump body. Coat seal lip with grease.
4. To install, apply sealant on rear of oil pump. Coat NEW "O" ring with oil and install on rear of oil pump. Install oil pump. Ensure splined teeth on rotor of oil pump engages with splines on crankshaft.
5. Install proper length bolts in designated locations. (Scheme 23) Tighten retaining bolts to specification.
6. Install baffle plate and retaining bolts. Tighten bolts to specification. Install gasket and pick-up tube. Tighten pick-up tube-to-oil pump bolts to specification, then pick-up tube support bracket bolts. To install remaining components, reverse removal procedure.

Scheme 23

1. Disconnect negative battery cable. Drain cooling system. Disconnect coolant hoses from oil cooler. Remove oil filter and remove retaining nut from filter adapter. Remove oil cooler and "O" ring from oil filter bracket.
2. To install, reverse removal procedure using NEW "O" ring coated with engine oil. Tighten retaining nut to specification. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000) . Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(ref-49161-S36555986632001011500000) under REMOVAL & INSTALLATION.

1. With crankshaft and main bearings removed, remove oil jet from cylinder block main bearing bore. (Scheme 24)
2. Ensure threads on oil jet and cylinder block are clean. Apply thread sealant on oil jet threads. Install oil jet and tighten to specification. See «TORQUE SPECIFICATIONS»(ref-49161-S23175338032001011500000).

Scheme 24