Dodge Nitro. Manual — part 109

Fig. 173: MD 998772A, Spark Plug Tubes, Cylinder Head, 6527 - Adaptor & Valve Spring Retainer
Courtesy of CHRYSLER LLC

1. Install new valve seal(s) if required. See INSTALLATION.

2. Place valve spring (color-coded end facing up) and valve retainer into position.

3. Compress valve spring using Special Tool MD 998772A (1) with Adaptor 6527 (4) only enough to install

locks (5). See Fig. 173.

1 - MD 998772A
2 - SPARK PLUG TUBES
3 - CYLINDER HEAD
4 - 6527 - ADAPTOR
5 - VALVE SPRING RETAINER

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

4. After installing locks, release tension on valve spring and verify proper installation.

5. Remove Special Tool MD 998772A (1) and spark plug adapter tool.

6. Install rocker arm and shaft assembly. See INSTALLATION.

7. Install cylinder head cover(s). See INSTALLATION).

8. Install spark plugs.

9. Install upper intake manifold. See INSTALLATION.

10. Connect negative battery cable.

CYLINDER BLOCK

DESCRIPTION

BLOCK-CYLINDER

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

Fig. 174: Main Caps, Bolts, Main Bearing-Lower, Crankshaft, Thrust Washers, Main Bearing-Upper &
Engine Block
Courtesy of CHRYSLER LLC

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

The cylinder block is made of heat treated aluminum with cast-in-place iron liners. The block is a closed deck
design with the right bank forward. To provide high rigidity and improved noise, vibration and harshness
(NVH), the block has cast-in contours and ribs, along with powdered metal 6 bolt main caps (4 vertical, 2
horizontal), with a die cast aluminum structural beam windage tray mounted to the main caps. See Fig. 174.

CLEANING

BLOCK-CYLINDER

Clean cylinder block thoroughly using a suitable cleaning solvent.

INSPECTION

BLOCK-CYLINDER

ENGINE BLOCK

1. Clean cylinder block thoroughly and check all core hole plugs for evidence of leaking.

2. If new core plugs are to be installed, see ENGINE CORE AND OIL GALLERY PLUGS.

3. Examine block and cylinder bores for cracks or fractures.

4. Check block deck surfaces for flatness. Deck surface must be within service limit of 0.1 mm (0.004 in.).

CYLINDER BORE

1 - MAIN CAPS
2 - BOLTS
3 - MAIN BEARING-LOWER
4 - CRANKSHAFT
5 - THRUST WASHERS
6 - MAIN BEARING-UPPER
7 - ENGINE BLOCK

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro