Cylinder Head

REMOVAL & INSTALLATION

2.5L Engine

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Drain the cooling system.
3. Drain the engine oil.
4. Relieve the fuel system pressure.
5. Remove or disconnect the following:
   • Battery and tray
   • Accessory drive belt
   • Water pump and drive pulley
   • Intake manifold
   • Power steering pump
   • Intake Manifold Runner Control (IMRC) actuator
   • Spark plug wires
   • Ignition coil
   • Heated Oxygen (HO2S) sensor connectors
   • Exhaust front pipe
   • Exhaust Gas Recirculation (EGR) pipe
   • Exhaust manifolds
   • Oil pan
   • Alternator
   • A/C compressor
   • Valve covers
   • Front cover
   • Timing chains
   • Camshafts
   • Cylinder heads. Loosen the bolts in several passes and in the sequence shown.

     Fig. 1: Left cylinder head loosening sequence — 2.5L engine

     Fig. 2: Right cylinder head loosening sequence — 2.5L engine

   To install:

   NOTE: The cylinder head bolts are a torque-to-yield design and must be replaced.

   NOTE: Refer to Section 1 of this manual for the cylinder head torque sequence illustration. The illustration is located after the Torque Specification Chart.

6. Install the cylinder heads with new gaskets. Tighten the bolts in sequence as follows:
   1. Step 1: 28–31 ft. lbs. (37–43 Nm)
   2. Step 2: Plus 90 degrees
   3. Step 3: Loosen one full turn
   4. Step 4: 28–31 ft. lbs. (37–43 Nm)
   5. Step 5: Plus 90 degrees
   6. Step 6: Plus 90 degrees
7. Install or connect the following:
   • Camshafts
   • Timing chains
   • Front cover
   • Valve covers
   • A/C compressor
   • Alternator
   • Oil pan
   • Exhaust manifolds
   • EGR pipe
   • Exhaust front pipe
   • HO2S sensor connectors
   • Ignition coil
   • Spark plug wires
   • IMRC actuator
   • Power steering pump
   • Intake manifold
   • Water pump and drive pulley
   • Accessory drive belt
   • Battery and tray
8. Fill the crankcase to the correct level.
9. Fill the cooling system.
10. Start the engine and check for leaks.

3.0L Engine

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Drain the cooling system.
3. Relieve the fuel system pressure.
4. Remove or disconnect the following:
   • Negative battery cable
   • Air intake assembly
   • Spark plug wires
   • Distributor
   • Accessory drive belts
   • Cooling fan and shroud
   • Upper radiator hose
   • Front cover
   • Timing belt. Refer to the Timing Belt unit repair section.
   • Intake manifold
   • Exhaust manifolds
   • Positive Crankcase Ventilation (PCV) valve and hose
   • Valve covers
   • Cylinder heads

     Fig. 4: Cylinder head bolt removal sequence — 3.0L engine

   To install:

   Fig. 5: Head gasket positioning — 3.0L engine

5. Measure the cylinder head bolts. Replace any that exceed the following specifications:
   • Intake side: 4.29 inches (109mm)
   • Exhaust side: 5.47 inches (139mm)

   NOTE: Refer to Section 1 of this manual for the cylinder head torque sequence illustration. The illustration is located after the Torque Specification Chart.

6. Install the cylinder heads with new gaskets. Tighten the bolts in sequence as follows:
   1. Step 1: 13–16 ft. lbs. (17–22 Nm)
   2. Step 2: Plus 85–95 degrees
   3. Step 3: Plus 85–95 degrees
7. Install or connect the following:
   • Valve covers
   • PCV valve and hose
   • Exhaust manifolds
   • Intake manifold
   • Timing belt
   • Front cover
   • Upper radiator hose
   • Cooling fan and shroud
   • Accessory drive belts
   • Distributor
   • Spark plug wires
   • Air intake assembly
   • Negative battery cable
8. Fill the cooling system.
9. Start the engine and check for leaks.