Cylinder Head

REMOVAL & INSTALLATION

1.5L Engine

1. Relieve the fuel system pressure.

   CAUTION
   Observe all applicable safety precautions when working around fuel. Whenever servicing the fuel system, always work in a well ventilated area. Do not allow fuel spray or vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion.

2. Disconnect the negative battery cable.
3. Drain the cooling system.

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

4. Remove the air intake hose and the air cleaner assembly.
5. Disconnect the ground cable connection and the accelerator cable.
6. Disconnect the PCV and the breather hose connection.
7. Label and disconnect the vacuum hoses from the intake and throttle body.
8. Disconnect the vacuum line for the brake booster.
9. Remove the upper radiator hose, throttle body hoses, bypass hose and heater hose connections.
10. Disconnect the fuel feed and return lines.
11. Remove the spark plug wires.
12. Disconnect the electrical harness plugs from the following:
    • Crankshaft Position (CKP) and Camshaft Position (CMP) sensors
    • Heated Oxygen (HO2S) sensor
    • Engine Coolant Temperature (ECT) sensor and gauge sender
    • Idle Speed Control (ISC) motor
    • Throttle Position (TP) sensor
    • Intake Air Temperature (IAT) sensor
    • Exhaust Gas Recirculation (EGR) temperature sensor
13. Disconnect electrical harness plugs from the ignition distributor, fuel injectors, power transistor and ground cable.
14. Disconnect the engine control wiring harness.
15. Remove the clamp that holds the power steering pressure hose to the engine mounting bracket.
16. Place a jack and wood block under the oil pan and carefully lift just enough to take the weight off the engine mounting bracket and remove the bracket.
17. Remove the valve cover.
18. Remove the timing belt upper cover.
19. Rotate the crankshaft clockwise and align the timing marks.
20. Attach the timing belt to the camshaft sprocket with cord or a wire tie.
21. Secure the camshaft from turning and remove the camshaft sprocket with the timing belt attached.
22. Remove the timing belt rear upper cover.
23. Remove the exhaust pipe from the exhaust manifold.
24. Loosen the cylinder head mounting bolts in sequence using three steps.
25. Remove the cylinder head.

    Fig. 1: Cylinder head bolt loosening sequence — Mirage with 1.5L (4G15) engine

    To install:

26. Thoroughly clean the mating surfaces of the head and block.
27. Place a new head gasket on the cylinder block with the identification marks facing upward. Do not use sealer on the gasket.
28. Carefully install the cylinder head on the block. Tighten the cylinder head bolts as outlined in the following steps:
    1. Tighten the bolts to 36 ft. lbs. (49 Nm) in the correct sequence
    2. Loosen the bolts completely in the reverse of the tightening order.
    3. Tighten the bolts, in sequence, to 14 ft. lbs. (20 Nm)
    4. Tighten each bolt, in sequence, 90 degrees
    5. Tighten each bolt, in sequence, an additional 90 degrees

       Fig. 2: Cylinder head bolt tightening sequence — Mirage with 1.5L (4G15) engine

29. Install a new exhaust pipe gasket and connect the exhaust pipe to the manifold.
30. Install the upper rear timing cover.
31. Align the timing marks and install the cam sprocket. Torque the retaining bolt to 51 ft. lbs. (70 Nm). Check the belt tension and adjust, if necessary. Install the outer timing cover.
32. Install the valve cover and torque the retaining bolts to 16 inch lbs. (1.8 Nm).
33. Install the engine mount bracket and remove the support jack.
34. Install the clamp that holds the power steering pressure hose to the engine mounting bracket.
35. Attach the following electrical connectors:
    • CKP and CMP sensors
    • HO2S sensor
    • ECT sensor and gauge sender
    • ISC motor
    • TP sensor
    • IAT sensor
    • EGR temperature sensor
36. Connect wiring for the ignition distributor, fuel injectors, power transistor and ground cable.
37. Connect the engine control wiring harness.
38. Replace the O-rings and connect the fuel lines.
39. Install the air cleaner assembly. Connect the breather hose.
40. Fill the system with coolant.
41. Connect the negative battery cable.

1.8L Engine

1. Relieve fuel system pressure. Disconnect the negative battery cable.
2. Remove the air cleaner assembly.
3. Drain the cooling system.

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

4. Disconnect the brake booster vacuum hose and PVC valve connection.
5. Note the locations, then disconnect the vacuum hoses from the intake and throttle body.
6. Remove the upper radiator hose, overflow tube and the water hose from the thermostat to the throttle body.
7. Disconnect the fuel feed and return lines.
8. Unplug the accelerator cable connection from the throttle body.
9. Detach the wiring from the oil pressure switch.
10. Disconnect the wiring from the following components:
    • Heated Oxygen (HO2S) sensor
    • Engine Coolant Temperature (ECT) sensor and gauge sender
    • Idle Air Control (IAC) motor
    • Exhaust Gas Recirculation (EGR) temperature sensor
    • Throttle Position (TP) sensor
    • Knock sensor
    • Fuel injectors
11. Remove the spark plug wires.
12. Unbolt the control harness assembly and position aside.
13. Remove the thermostat housing, thermostat and the thermostat case with O-ring from the engine.
14. Remove the rocker cover.
15. Remove the timing belt upper cover.
16. Rotate the crankshaft clockwise and align the timing marks.
17. Attach the timing belt to the camshaft sprocket with cord or a wire tie.
18. Secure the camshaft from turning and remove the camshaft sprocket with the timing belt attached.
19. Remove the timing belt rear upper cover.

    Fig. 3: Cylinder head bolt loosening sequence — 1.8L engine

20. Loosen the cylinder head bolts in two or three steps in the proper sequence.
21. Remove the cylinder head from the engine.

    CAUTION
    When removing the cylinder head, take care not to bend or damage the plug guide. The plug guide can not be replaced.

    To install:

22. Thoroughly clean the mating surfaces of the head and block.
23. Place a new head gasket on the cylinder block with the identification marks facing upward. Do not use sealer on the gasket.
24. Carefully install the cylinder head on the block.
25. Measure the cylinder head bolts prior to installation. Replace any that exceed 3.795 in. (96.4mm).
26. Apply a small amount of engine oil to the thread section of the bolt and install so the chamfer of the washer faces upward.

    Fig. 4: Cylinder head bolt torque sequence — 1.8L engine

27. Tighten the cylinder head bolts as follows:
    1. In the proper tightening sequence, torque bolts to 54 ft. lbs. (75 Nm).
    2. In the reverse order of the tightening sequence, fully loosen all bolts.
    3. In the proper tightening sequence, torque bolts to 14 ft. lbs. (20 Nm).
    4. In the proper tightening sequence, tighten bolts ¹⁄₄ turn (90 degrees).
    5. In the proper tightening sequence, tighten bolts an additional ¹⁄₄ turn (90 degrees).
28. Install the camshaft sprocket and tighten the bolt to 65 ft. lbs. (90 Nm), while holding the sprocket in place using the appropriate wrench. Confirm proper timing mark alignment.
29. Install the upper timing belt cover and rocker cover. Torque the rocker cover bolts to 29 inch lbs. (3 Nm).
30. Loosen the water pipe mounting bolt for ease of thermostat housing installation.
31. Apply a thin bead of sealant MD970389 or equivalent, to the water tube connection on the thermostat case.
32. Apply a small amount of water to the O-ring of the water inlet pipe and press the thermostat case assembly onto the water inlet pipe. Install the thermostat case assembly mounting bolt tightening to 16 ft. lbs. (22 Nm).
33. Tighten the water pipe mounting bolt.
34. Install the thermostat into the housing so the jiggle valve is located at the top. Tighten the housing bolts to 10 ft. lbs. (14 Nm).
35. Attach the wiring to the following components:
    • HO2S sensor
    • ECT sensor and gauge sender
    • IAC motor
    • EGR temperature sensor
    • TP sensor
    • Knock sensor
    • Fuel injectors
36. Connect the upper radiator hose to the thermostat housing.
37. Connect the accelerator cable connection to the throttle body.
38. Connect the oil pressure switch.
39. Install the spark plug wires.
40. Connect the control harness assembly.
41. Replace the O-ring for the high pressure hose and install a new clamp on the return hose and reconnect the fuel lines.
42. Install the air intake hose. Connect the breather hose and air cleaner case cover.
43. Reconnect the brake booster and the PCV vacuum hoses.
44. Fill the system with coolant.
45. Connect the negative battery cable

2.0L SOHC Engine

1. Disconnect the negative battery cable.
2. Drain the cooling system.

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

3. Remove the air intake hose.
4. Disconnect the accelerator cable and remove the bracket.
5. Disconnect the high pressure fuel line and remove the O-ring.

   CAUTION
   Observe all applicable safety precautions when working around fuel. Whenever servicing the fuel system, always work in a well ventilated area. Do not allow fuel spray or vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion.

6. Disconnect the upper radiator hose, the coolant by-pass hose and the heater hose from the head and/or intake manifold.
7. Disconnect the brake booster vacuum hose.
8. Remove the fuel return hose.
9. Label and detach the vacuum hose(s) running to the manifold. Disconnect the PCV hose at the valve cover.
10. Tag and disconnect the spark plug wires from the distributor cap.
11. Label and detach each electrical connector, including the distributor lead and the injector connectors. Note that some of the wiring must be disconnected at the firewall. When all the connectors are loose, remove the bracket bolts holding the control wiring harness in place and move the harness to an out-of-the-way location.
12. Remove the clamp holding the power steering and air conditioning hoses to the top of the left engine mount bracket. Move the hoses out of the way but don't disconnect either hose from its system.
13. Position a floor jack and a broad piece of lumber under the engine. Elevate the jack just enough to support the engine without raising it.
14. Remove the through-bolt from the left side engine mount. It may be necessary to adjust the jack slightly to allow the bolt to come free. When the bolt has been removed, disconnect the nuts and bolts holding the mounting bracket to the engine and remove the bracket.
15. Remove the valve cover and gasket. Remove the half-circle plug from the head.
16. Remove the upper timing belt cover. Turn the crankshaft clockwise until all the timing marks align, setting the engine to TDC/compression for No. 1 cylinder.
17. Remove the bolt holding the camshaft sprocket to the camshaft. Remove the camshaft sprocket, with the belt attached, and place it on the lower timing belt cover. Do NOT allow the belt to come off the sprocket.

    WARNING
    Do not rotate the crankshaft once the camshaft sprocket is removed.

18. Remove the self-locking nuts and the small retaining bolt holding the exhaust pipe to the bottom of the exhaust manifold. Separate the pipe from the manifold and remove the gasket.
19. Remove the bolts holding the support brace to the bottom of the intake manifold.
20. Use the special hex wrench (MB 998051-01) and loosen the head bolts in the order shown in 2 or 3 passes. When all are finger loose, remove the bolts.
21. Rock the head gently to break it loose; if tapping is necessary, do so with a rubber or wooden mallet at the corners of the head. DO NOT pry the head up by wedging tools between the head and the block.
22. Lift the head free of the engine. It is coming off with both manifolds and the intake plenum attached; the help of an assistant is recommended for lifting. Support the head assembly on wooden blocks on a suitable workbench. Refer to Cleaning and Inspection in this section for work to be done before installing the head. If the head has been removed for work other than gasket replacement, the rocker assembly and camshaft or other components may be removed.

    Before reinstallation, the head should be completely assembled on the bench. This allows proper location and tightening of all the external items.

    To install:

23. Place a new gasket on the engine so that the identifying mark faces up (towards the head) and is at the timing belt end of the block. Install a new gasket on the exhaust pipe.

    WARNING
    Do not apply sealant to the head gasket or mating surfaces.

24. Install the head straight down onto the block. Try to eliminate most of the side–to–side adjustments as this may move the gasket out of position. Install the bolts by hand and just start each bolt 1 or 2 turns on the threads.
25. The head bolt torque specification is 68 ft. lbs. (92 Nm) for a cold engine. The bolts must be tightened in the order shown in 3 steps. On the first pass, tighten all the bolts to about 22 ft. lbs. (30 Nm), then proceed through the order tightening each bolt to about 45 ft. lbs. (61 Nm). The final torque is achieved on the third pass.
26. Install the intake manifold support brace to the manifold and tighten the bolts to 16 ft. lbs. (22 Nm).
27. Making sure the gasket is still in place, connect the exhaust pipe to the base of the exhaust manifold. Use new self-locking nuts; tighten the nuts and the small bracket bolt to 26 ft. lbs. (35 Nm).
28. Make sure the camshaft has not changed position during repairs. Carefully install the camshaft sprocket and belt onto the camshaft. Tighten the retaining bolt to 66 ft. lbs. (91 Nm).
29. Install the upper timing belt cover, then tighten the bolts to 8 ft. lbs. (11 Nm).
30. Apply sealant to the contact surfaces of the half-circle plug and install the plug in the head. Install the valve cover and gasket.
31. Install the engine mount bracket to the engine. Tighten the mounting nuts and bolts to 42 ft. lbs. (57 Nm).
32. Adjust the jack (if necessary) so that the engine mount bushing aligns with the bodywork bracket. Install the through-bolt and tighten the nuts snug.
33. Slowly release tension on the floor jack so that the weight of the engine bears fully on the mount. Tighten the through-bolt to 52 ft. lbs. (71 Nm) and the small safety nut to 26 ft. lbs. (36 Nm).
34. Install the bracket holding the power steering hose and air conditioning hose to the top of the engine mount.
35. Position the control wiring harness and install the retaining bolts. Attach each electrical connector to its proper location, making sure the wires are properly routed and firmly connected.
36. Install the spark plug wires in the distributor cap.
37. Connect the PCV hose and the vacuum hose(s).
38. Connect the fuel return line. Connect the brake booster vacuum hose.
39. Install the heater hose, the coolant by-pass hose and the upper radiator hose. Pay close attention to the position and routing of these hoses and insure that they are not crimped or constricted. Install the clamps in the same location as before removal.
40. Install a new O-ring on the high pressure fuel line and lubricate it with a coating of gasoline. Carefully connect the high pressure fuel line to the fuel rail, taking care not to damage the O-ring. Tighten the bolts only to 4 ft. lbs. (6 Nm).
41. Connect the accelerator cable and adjust it as necessary.
42. Install the air intake hose.
43. Fill the cooling system with coolant.
44. Changing the oil and filter is recommended to eliminate pollutants in the oil.

    WARNING
    Operating the engine without the proper amount and type of engine oil will result in severe engine damage.

45. Connect the negative battery cable.
46. Start the engine and check for leaks of fuel, vacuum or oil.
47. Check the operation of all engine electrical systems as well as dashboard gauges and lights.
48. Perform necessary adjustments to the accelerator cable, drive belts and engine specifications. Adjust the coolant level after the engine has cooled off.

1.6L and 2.0L DOHC Engines

1. Relieve fuel system pressure.
2. Disconnect the negative battery cable.
3. Drain the cooling system.

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

4. Disconnect the accelerator cable. There will be 2 cables if equipped with cruise-control.
5. Remove the air cleaner with the air intake hose.
6. Detach the electrical connectors from the the oxygen sensor, engine coolant temperature sensor, the engine coolant temperature gauge unit and the engine coolant temperature switch on vehicles with air conditioning.
7. Disconnect the wiring from the ISC motor, throttle position sensor, crankshaft angle sensor, fuel injectors, ignition coil, power transistor, noise filter, knock sensor on turbocharged engines, EGR temperature sensor (California vehicles), ground cable and engine control wiring harness.
8. Remove the upper radiator hose and the overflow tube.
9. Remove the spark plug cable center cover, then remove the spark plug cables.
10. Disconnect and plug the high pressure fuel line.
11. Disconnect the small vacuum hoses.
12. Remove the heater hose and water bypass hose.
13. Remove the PCV hose.
14. If turbocharged, remove the vacuum hoses, water line and eyebolt connection for the oil line for the turbo.
15. Disconnect and plug the fuel return hose.
16. Disconnect the brake booster vacuum hose.
17. Remove the timing belt.
18. Remove the valve cover and the half-round seal.
19. On non-turbocharged engines, remove the exhaust pipe self-locking nuts and separate the exhaust pipe from the exhaust manifold. Discard the gasket.
20. On turbocharged engines, remove the sheet metal heat protector and remove the bolts that attach the turbocharger to the exhaust manifold.
21. Loosen the cylinder head mounting bolts in 3 steps, starting from the outside and working inward. Lift off the cylinder head assembly and remove the head gasket.

    To install:

22. Thoroughly clean and dry the mating surfaces of the head and block. Check the cylinder head for cracks, damage or engine coolant leakage. Remove scale, sealing compound and carbon. Clean oil passages thoroughly. Check the head for flatness. End to end, the head should be within 0.002 in. (0.05mm) normally, with 0.008 in. (0.2mm) the maximum allowed out of true. The total thickness allowed to be removed from the head and block is 0.008 in. (0.2mm) maximum.
23. Place a new head gasket on the cylinder block with the identification marks at the front top (upward) position. Make sure the gasket has the proper identification mark for the engine. Do not use sealer on the gasket. Replace the turbo gasket and ring, if equipped.
24. Carefully install the cylinder head on the block. Using 3 even steps, torque the head bolts, in sequence, to 65–72 ft. lbs. (90–100 Nm). This torque applies to a cold engine. If checking cylinder head bolt torque on hot engine, the desired specification is 72–80 ft. lbs. (100–110 Nm).
25. On turbocharged engine, install the heat shield. On non-turbocharged engines, install a new exhaust pipe gasket and connect the exhaust pipe to the manifold.
26. Apply sealer to the perimeter of the half-round seal and to the lower edges of the half-round portions of the belt-side of the new gasket. Install the valve cover.
27. Install the timing belt and all related items.
28. Connect or install all previously disconnected hoses, cables and electrical connections. Adjust the throttle cable(s).
29. Install the spark plug cable center cover.
30. Replace the O-rings and connect the fuel lines.
31. Install the air cleaner and intake hose. Connect the breather hose.
32. Change the engine oil and oil filter.
33. Fill the system with coolant.
34. Connect the negative battery cable.
35. Run the vehicle until the thermostat opens, and fill the radiator completely.
36. Check and adjust the idle speed and ignition timing.
37. Once the vehicle has cooled, recheck the coolant level.

2.4L Engine

1. Relieve the fuel system pressure.
2. Disconnect the negative battery cable.
3. Remove the air cleaner with all air intake hoses.
4. Drain the cooling system.

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

5. Disconnect the accelerator cable. Remove the cable mounting brackets and position the cable aside.
6. Remove the breather hose.
7. Label and disconnect the vacuum lines at the throttle body.
8. Disconnect and plug the high pressure fuel line.
9. Disconnect and plug the fuel return hose.
10. Label and detach the connectors from the following components:
    • A/C compressor
    • Power steering pressure switch
    • Heated Oxygen (HO2S) sensor
    • Engine Coolant Temperature (ECT) gauge sender
    • ECT sensor
    • Manifold Absolute Pressure (MAP) sensor
    • Intake Air Temperature (IAT) sensor
    • Throttle Position (TP) sensor
    • Idle Air Control (IAC) motor
    • Injector harness
    • Ignition coil
    • Camshaft Position (CMP) sensor
    • Exhaust Gas Recirculation (EGR) solenoid valve
11. Remove the spark plug wire cover and wires.
12. At the thermostat case assembly, remove the coolant hoses and unbolt the thermostat case from the engine.
13. Remove the upper timing belt cover.
14. Align all timing marks.
15. Secure the timing belt to the camshaft sprocket with cord or a wire tie.
16. Remove the camshaft sprocket.
17. Remove the valve cover and the half-round seal.
18. Disconnect the intake manifold stay bracket from the intake manifold.
19. Remove the exhaust pipe self-locking nuts and separate the exhaust pipe from the exhaust manifold. Discard the gasket.
20. Loosen the cylinder head mounting bolts in 3 steps, starting from the outside and working inward. Lift off the cylinder head assembly and remove the head gasket.

    To install:

21. Thoroughly clean the mating surfaces of the head and block.
22. Place a new head gasket on the cylinder block with the identification marks at the front top (upward) position. Do not use sealer on the gasket.
23. Inspect the cylinder head bolt length prior to installation. If the length exceeds 3.91 in. (99.4mm), the bolt must be replaced. Install the washer onto the bolt so the chamfer on the washer faces towards the head of the bolt.
24. Carefully install the cylinder head on the block and tighten the cylinder head bolts as follows:
    1. Following the proper tightening sequence, tighten the cylinder head bolts to 58 ft. lbs. (78 Nm).
    2. Loosen all bolts completely.
    3. Torque bolts to 15 ft. lbs. (20 Nm).
    4. Tighten bolts an additional ¹⁄₄ turn.
    5. Tighten bolts an additional ¹⁄₄ turn.

       Fig. 39: Cylinder head bolt installation sequence — 2.4L (4G64) engine

25. Install the new exhaust pipe gasket and connect the exhaust pipe to the manifold. Tighten the bolts to 33 ft. lbs. (44 Nm).
26. Install the thermostat case and tighten the mounting bolts to 18 ft. lbs. (24 Nm).
27. Connect the coolant hoses to the thermostat case.
28. Apply sealer to the perimeter of the half-round seal and to the lower edges of the half-round portions of the belt-side of the new gasket. Install the valve cover.
29. Install the camshaft sprocket with the timing belt attached. Remove the cord or wire tie.
30. Install the upper timing belt cover.
31. Connect the intake manifold stay and tighten the mounting bolts to 22 ft. lbs. (30 Nm).
32. Attach the connectors to the following components:
    • A/C compressor
    • Power steering pressure switch
    • HO2S sensor
    • ECT gauge sender
    • ECT sensor
    • MAP sensor
    • IAT sensor
    • TP sensor
    • IAC motor
    • Injector harness
    • Ignition coil
    • CMP sensor
    • EGR solenoid valve
33. Install the spark plug wires and cover.
34. Replace the O-rings and connect the fuel lines.
35. Install the air cleaner and intake hose. Connect the breather hose.
36. Fill the cooling system.
37. Connect the negative battery cable

3.0L DOHC Engine

1. Relieve fuel system pressure. Disconnect the negative battery cable.
2. Drain the cooling system.

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

3. Remove the air intake hoses.
4. Remove air intake plenum and intake manifold.
5. Remove the exhaust manifold.
6. Remove the timing belt. Refer to the timing belt procedure in this section.
7. Remove the breather hose.
8. Remove the spark plug wire center cover and remove the spark plug wires.
9. Remove the rocker covers.
10. Remove the intake camshaft sprockets.
11. Remove the rear timing belt cover.
12. Remove the ignition coil assembly.
13. Disconnect all water hoses from the thermostat housing and remove the housing.
14. Disconnect the water inlet from the front head.
15. Loosen the cylinder head mounting bolts in the reverse of the torque sequence and loosen the bolts in three steps. Lift off the cylinder head assembly and remove the head gasket.

    To install:

16. Thoroughly clean the sealing surfaces of the head and block.
17. Place a new head gasket on the cylinder block with the identification marks in the front top (upward) position. Do not use sealer on the gasket.
18. Carefully install the cylinder head on the block. Be sure the head bolt washers are installed with the chamfered edge upward. Using three even steps, torque the head bolts in sequence, to 76–83 ft. lbs. (105–115 Nm).

    Fig. 40: Tighten the cylinder head bolts according to the sequence shown — 3.0L (SOHC and DOHC) engines

    Fig. 41: Rocker cover bolt torque sequence — Diamante 3.0L DOHC engine

19. Install new O-ring and connect the water inlet to the head. Tighten the mounting bolt to 9–11 ft. lbs. (12–15 Nm).
20. Replace the gaskets and install the thermostat housing. Tighten the mounting bolts to 12–14 ft. lbs. (17–20 Nm).
21. Using new hose clamps, connect the hoses to the thermostat housing.
22. Install the ignition coil and torque the mounting bolts to 7 ft. lbs. (10 Nm).
23. Install the rear timing belt cover and torque the mounting bolts to 17 ft. lbs. (24 Nm).
24. Install the intake camshaft sprockets. Tighten the retaining bolt to 65 ft. lbs. (90 Nm).
25. Apply sealer to the lower edges of the valve cover. Tighten the bolts in the proper sequence to 44–51 inch lbs. (5–6 Nm).
26. Connect the spark plug wires and install the center cover. Tighten the bolts that secure the center cover to 27 inch lbs. (3 Nm)
27. Install the breather hose.
28. Install the timing belt. Refer to the timing belt procedure in this section.
29. Install the exhaust manifold assembly.
30. Using all new gaskets, install the intake manifold and air intake plenum.
31. Install the air intake hoses.
32. Change the engine oil and oil filter.
33. Fill the system with coolant.
34. Connect the negative battery cable.
35. Adjust the accelerator cable.
36. Start the engine.
37. Check and adjust the idle speed and ignition timing.
38. Once the vehicle has cooled, recheck the coolant level.

3.0L SOHC Engine

1. Relieve the fuel system pressure.
2. Disconnect the negative battery cable.
3. Drain the cooling system.

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

4. Remove the air intake hose.
5. Remove the exhaust manifold.
6. Remove the air intake plenum and intake manifold.
7. Remove the timing belt. Refer to the timing belt procedure in this section.
8. Remove the camshaft sprockets and the rear timing belt cover.
9. Remove the power steering pump bracket. If removing the rear head, remove the alternator brace.
10. Disconnect the water inlet pipe.
11. Remove the purge pipe assembly.
12. Remove the valve cover.
13. Using the reverse sequence of the installation sequence, loosen the cylinder head mounting bolts in three steps. Lift off the cylinder head assembly and remove the head gasket.

    To install:

14. Thoroughly clean the sealing surfaces of the head and block.
15. Place a new head gasket on the cylinder block making sure the identification mark on the cylinder head gasket is in the front top (upward) location. Do not use sealer on the gasket.
16. Carefully install the cylinder head on the block. Be sure the head bolt washers are installed with the chamfered edge upward. Using three even steps, torque the head bolts in sequence, to 76–83 ft. lbs. (105–115 Nm).
17. Apply sealer to the lower edges of the half-round portions and install the valve cover. Tighten valve cover bolts to 7 ft. lbs. (9 Nm).
18. Install the purge pipe assembly.
19. Connect the water inlet pipe.
20. Install the power steering pump bracket and alternator brace.
21. Install the rear timing belt cover and camshaft sprockets. Torque the retaining bolt to 65 ft. lbs. (90 Nm).
22. Install the timing belt. Refer to the timing belt procedure in this section.
23. Using all new gaskets, install the intake manifold, air intake plenum and exhaust manifold.
24. Install the air intake hose.
25. Fill the system with coolant.
26. Connect the negative battery cable.
27. Start the engine.
28. Check and adjust the idle speed and ignition timing.
29. Once the vehicle has cooled, recheck the coolant level.

3.5L Engine

1. Disconnect the negative battery cable.
2. Drain the engine coolant

   CAUTION
   Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

3. Remove the timing belt. Refer to the timing belt procedure in this section.
4. Remove the intake and exhaust manifolds.
5. Remove the spark plug wires.
6. Remove the cylinder head covers.
7. Remove the timing belt rear center cover.
8. Loosen the cylinder head bolts gradually in three stages, in the opposite of the installation sequence.
9. Remove the cylinder head.

   To install:

10. Clean the cylinder head and mounting surface on the engine block.
11. Install the cylinder head using a new gasket.
12. Tighten the bolts in sequence using three stages to 76–83 ft. lbs. (103–113 Nm).

    Fig. 42: Cylinder head bolt tightening sequence — 3.5L engine

13. Install the timing belt rear center cover.
14. Install the cylinder head covers using new gaskets. Tighten the bolts to 2–3 ft. lbs. (3–4 Nm).
15. Install the spark plug wires.
16. Install the intake and exhaust manifolds.
17. Install the timing belt. Refer to the timing belt procedure in this section.
18. Install any remaining components.
19. Refill the cooling system.
20. Connect the negative battery cable.