Dodge Nitro. Manual — part 102

Fig. 149: Valve Seal & Spring-Installation
Courtesy of CHRYSLER LLC

5. Compress valve springs (4) with valve spring compressor C-3422-D and adapter 6526. See SPECIAL

TOOLS, install locks (2) and release tool.

6. If valves (1) and/or seats are refaced, measure the installed height of springs. See Fig. 147. Measurements

are taken from top of spring (4) seat to the bottom surface of spring retainer. If height is greater than
38.75 mm (1.5256 in.), install a 0.762 mm (0.030 in.) spacer in head counterbore under the valve spring
seat to bring spring height back within specification.

REMOVAL

1 - VALVE
2 - VALVE RETAINING LOCKS
3 - VALVE SPRING RETAINER
4 - VALVE SPRING
5 - VALVE SEAL AND VALVE SPRING SEAT
ASSEMBLY

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

VALVES

1. Remove cylinder head(s). See REMOVAL.

2. Remove rocker arm assembly. See REMOVAL.

3. Remove valve spring(s). See REMOVAL.

4. Before removing valve, remove any burrs from valve stem lock grooves to prevent damage to the

valve guides. Identify valves to insure installation in original location.

5. Remove valve(s) from cylinder head.

CLEANING

VALVE AND VALVE SPRING

1. Clean all valves thoroughly and discard burned, warped and cracked valves.

INSPECTION

VALVE GUIDES

Fig. 150: Measuring Valve Guide Wear
Courtesy of CHRYSLER LLC

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

1. Measure valve stem-to-guide clearance as follows:

2. Install valve into cylinder head so it is 15 mm (0.590 inch.) off the valve seat. A small piece of hose may

be used to hold valve in place.

3. Attach dial indicator Tool C-3339 to cylinder head and set it at right angle of valve stem being measured.

See Fig. 150.

4. Move valve to and from the indicator.

5. Note dial indicator reading and compare to engine specifications. See SPECIFICATIONS.

VALVES

Fig. 151: Intake & Exhaust Valves
Courtesy of CHRYSLER LLC

NOTE:

Replace cylinder head if stem-to-guide clearance exceeds specifications, or if
guide is loose in cylinder head.

1 - MARGIN
2 - FACE
3 - STEM

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

1. Measure valve stems for wear approximately 60 mm (2.36 in.) below the valve lock grooves. See Fig.

151.

2. Compare measurement to specifications, see SPECIFICATIONS.

INSTALLATION

VALVES

Fig. 152: Checking Valve Tip Height & Valve Spring Installed Height
Courtesy of CHRYSLER LLC

1. Coat valve stems with clean engine oil and insert them in cylinder head.

4 - VALVE SPRING RETAINER LOCK GROOVES

NOTE:

Valve stems are chrome plated and should not be polished. See Fig. 151.

1 - SPRING RETAINER
2 - GARTER SPRING
3 - VALVE SPRING SEAT TOP
4 - CYLINDER HEAD SURFACE

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro