Dodge Nitro. Manual — part 29

REMOVAL

CYLINDER HEAD COVER

1. Disconnect battery negative cable.

2. Remove air cleaner assembly, resonator assembly and air inlet hose.

3. Drain cooling system, below the level of the heater hoses. Refer to STANDARD PROCEDURE .

4. Remove accessory drive belt. Refer to REMOVAL .

5. Remove air conditioning compressor retaining bolts and move compressor to the left.

6. Remove heater hoses.

7. Disconnect injector and ignition coil connectors.

8. Disconnect and remove positive crankcase ventilation (PCV) hose.

9. Remove oil fill tube.

10. Un-clip injector and ignition coil harness and move away from cylinder head cover.

11. Remove right rear breather tube and filter assembly.

12. Remove cylinder head cover retaining bolts.

13. Remove cylinder head cover.

INSTALLATION

CYLINDER HEAD COVER

1. Clean cylinder head cover and both sealing surfaces. Inspect and replace gasket as necessary.

2. Tighten cylinder head cover bolts and double ended studs to 12 N.m (105 in. lbs).

3. Install right rear breather tube and filter assembly.

4. Connect injector, ignition coil electrical connectors and harness retaining clips.

5. Install the oil fill tube.

6. Install PCV hose.

7. Install heater hoses.

8. Install air conditioning compressor retaining bolts.

9. Install accessory drive belt. Refer to INSTALLATION .

10. Fill Cooling system. Refer to STANDARD PROCEDURE .

11. Install air cleaner assembly, resonator assembly and air inlet hose.

12. Connect battery negative cable.

CAUTION: Do not use harsh cleaners to clean the cylinder head covers. Severe

damage to covers may occur.

NOTE:

The gasket may be used again, provided no cuts, tears, or deformation has
occurred.

2007 Dodge Nitro R/T

2007 ENGINE 3.7L - Service Information - Nitro

VALVES AND SEATS - INTAKE/EXHAUST

DESCRIPTION

VALVES

The valves are made of heat resistant steel and have chrome plated stems to prevent scuffing. Each valve is
actuated by a roller rocker arm which pivots on a stationary lash adjuster. All valves use three bead lock keepers
to retain the springs and promote valve rotation.

STANDARD PROCEDURE

REFACING

2007 Dodge Nitro R/T

2007 ENGINE 3.7L - Service Information - Nitro

Fig. 90: Valve Assembly Configuration
Courtesy of CHRYSLER LLC

1 - VALVE LOCKS (3-BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE

2007 Dodge Nitro R/T

2007 ENGINE 3.7L - Service Information - Nitro

1. Using a suitable dial indicator measure the center of the valve seat. Total run out must not exceed 0.051

mm (0.002 in).

2. Apply a small amount of Prussian blue to the valve seat, insert the valve into the cylinder head, while

applying light pressure on the valve rotate the valve. Remove the valve and examine the valve face. If the
blue is transferred below the top edge of the valve face, lower the valve seat using a 15 degree stone. If
the blue is transferred to the bottom edge of the valve face, raise the valve seat using a 65 degree stone.

3. When the seat is properly positioned the width of the intake seat must be 1.75 - 2.36 mm (0.0689 - 0.0928

in.) and the exhaust seat must be 1.71 - 2.32 mm (0.0673 - 0.0911 in.).

4. Check the valve spring (6) installed height after refacing the valve and seat. The installed height for both

intake and exhaust valve springs must not exceed 40.74 mm (1.6039 in.)

5. The valve seat and valve face must maintain a face angle of 44.5 - 45° angle.

REMOVAL

VALVES AND VALVE SPRINGS

5 - EXHAUST VALVE
6 - VALVE SPRING

NOTE:

Valve seats that are worn or burned can be reworked, provided that correct
angle and seat width are maintained. Otherwise the cylinder head must be
replaced.

NOTE:

When refacing valves (4) and valve seats, it is important that the correct size
valve guide pilot be used for reseating stones. A true and complete surface
must be obtained.

2007 Dodge Nitro R/T

2007 ENGINE 3.7L - Service Information - Nitro