Dodge Nitro. Manual — part 89

Fig. 94: Cylinder Head Bolt Tightening Sequence
Courtesy of CHRYSLER LLC

24. Remove the cylinder head bolts in REVERSE of tightening sequence.

25. Remove the cylinder head.

26. Clean and inspect all mating surfaces.

CLEANING

CYLINDER HEAD

To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of
aluminum engine components and multi-layer steel cylinder head gaskets.

Remove all gasket material from cylinder head and block. See STANDARD PROCEDURE. Be careful not to
gouge or scratch the aluminum head sealing surface.

Clean all engine oil passages.

INSPECTION

CYLINDER HEAD

NOTE:

Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

Fig. 95: Checking Cylinder Head Flatness
Courtesy of CHRYSLER LLC

1. Before cleaning, check for leaks, damage and cracks.

2. Clean cylinder head and oil passages.

3. Check cylinder head for flatness. See Fig. 95.

4. Cylinder head must be flat within:

Standard dimension = less than 0.05 mm (0.002 inch.)

Service Limit = 0.2 mm (0.008 inch.)

Grinding Limit = Maximum of 0.2 mm (0.008 inch.) is permitted.

INSTALLATION

CYLINDER HEAD - INSTALLATION

RIGHT CYLINDER HEAD

CAUTION: 0.20 mm (0.008 in.) MAX is a combined total dimension of the stock

removal limit from cylinder head and block top surface (Deck) together.

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

Fig. 96: Checking For Stretched Bolts
Courtesy of CHRYSLER LLC

The cylinder head bolts are tightened using a torque plus angle procedure. The bolts must be examined
BEFORE reuse. If the threads are necked down the bolts must be replaced. .

Necking can be checked by holding a scale or straight edge against the threads. If all the threads do not contact
the scale the bolt must be replaced.

1 - STRETCHED BOLT
2 - THREADS ARE NOT STRAIGHT ON LINE
3 - THREADS ARE STRAIGHT ON LINE
4 - UNSTRETCHED BOLT

CAUTION: THE CYLINDER HEAD GASKETS ARE NOT INTERCHANGEABLE

BETWEEN CYLINDER HEADS AND ARE CLEARLY MARKED RIGHT OR
LEFT.

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro

Fig. 97: Cylinder Head Bolt Tightening Sequence
Courtesy of CHRYSLER LLC

1. Clean sealing surfaces of cylinder head and block.

2. Install the cylinder head over locating dowels and finger tighten the head bolts.

3. Tighten the cylinder head bolts in the following sequence, using the 4 step torque-turn method. Tighten

according to the following torque values:

Step 1: All to 61 N.m (45 ft. lbs.)

Step 2: All to 88 N.m (65 ft. lbs.)

Step 3: All (again) to 88 N.m (65 ft. lbs.)

Step 4: + 90° Turn Do not use a torque wrench for this step.

4. Bolt torque after 90° turn should be over 122 N.m (90 ft. lbs.) in the tightening direction. If not, replace

CAUTION: When cleaning cylinder head and cylinder block surfaces, DO NOT use a

metal scraper because the surfaces could be cut or ground. Use ONLY a
wooden or plastic scraper. See ENGINE GASKET SURFACE
PREPARATION.

CAUTION: Ensure that the correct head gaskets are used and are oriented

correctly on cylinder block.

NOTE:

Before installing the cylinder head bolts, lubricate the threads with clean
engine oil.

2007 Dodge Nitro R/T

2007 ENGINE 4.0L - Service Information - Nitro