4.7L Engine - Service Information: Overview Dodge Durango II

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - INTRODUCTION

Engine diagnosis is helpful in determining the causes of malfunctions not detected and remedied by routine maintenance.

These malfunctions may be classified as either performance (e.g., engine idles rough and stalls) or mechanical (e.g., a strange noise).

(Refer to DIAGNOSIS AND TESTING - PERFORMANCE ,) and (Refer to DIAGNOSIS AND TESTING-MECHANICAL ) for possible causes and corrections of malfunctions. Refer to FUEL INJECTION or FUEL DELIVERY for the fuel system diagnosis.

Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that can not be isolated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided within the following diagnosis

1. Cylinder Compression Pressure Test (Refer to «DIAGNOSIS AND TESTING»(ref-212815-S28810293192005122700000) ).
2. Cylinder Combustion Pressure Leakage Test (Refer to «DIAGNOSIS AND TESTING»(ref-212815-S28810293192005122700000) ).
3. Engine Cylinder Head Gasket Failure Diagnosis (Refer to «DIAGNOSIS AND TESTING»(ref-212815-S40003135242005122700000) ).
4. Intake Manifold Leakage Diagnosis (Refer to «DIAGNOSIS AND TESTING»(ref-212815-S39402187742005122700000) ).

GENERAL DESCRIPTION

4.7L ENGINE GENERAL SPECIFICATIONS

DESCRIPTION - CYLINDER HEAD

The cylinder heads are made of an aluminum alloy. The cylinder head features two valves per cylinder with pressed in powdered metal valve guides. The cylinder heads also provide enclosures for the timing chain drain, necessitating unique left and right cylinder heads.

DESCRIPTION - VALVE GUIDES

The valve guides are made of powered metal and are pressed into the cylinder head. The guides are not replaceable or serviceable, and valve guide reaming is not recommended. If the guides are worn beyond acceptable limits, replace the cylinder heads.

Scheme 180

Scheme 181

Scheme 182

Scheme 183

1. Disconnect the negative cable from the battery.
2. Remove the wiper module (Refer to «MODULE-WINDSHIELD WIPER»(ref-212806-S16497299482005122700000) ).
3. Raise the vehicle on a hoist.
4. Disconnect the exhaust pipe at the left side exhaust manifold.
5. Drain the engine coolant. Refer to «DRAINING COOLING SYSTEM - ALL ENGINES»(ref-212747-S18408552002005122700000) .
6. Lower the vehicle.
7. Remove the intake manifold (Refer to «REMOVAL»(ref-212815-S30348470442005122700000) ).
8. Remove the cylinder head cover (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,).
9. Remove the fan shroud and fan blade assembly (Refer to «FAN-RADIATOR VISCOUS»(ref-212747-S08435546542006072400000) ).
10. Remove accessory drive belt (Refer to «BELTS-DRIVE»(ref-212748-S08533630352005122700000) ).
11. Remove the power steering pump and set aside.
12. Rotate the crankshaft until the damper timing mark is aligned with TDC indicator mark.
13. Verify the V8 mark on the camshaft sprocket is at the 12 o'clock position. Rotate the crankshaft one turn if necessary.
14. Remove the crankshaft damper (Refer to «DAMPER-CRANKSHAFT»(ref-212815-S27538834182005122700000) ).
15. Remove the timing chain cover (Refer to «REMOVAL»(ref-212815-S12373249852005122700000) ).
16. Lock the secondary timing chains to the idler sprocket using Special Tool 8515. NOTE: Mark the secondary timing chain prior to removal to aid in installation.
17. Mark the secondary timing chain, one link on each side of the V8 mark on the camshaft drive gear.
18. Remove the left side secondary chain tensioner (Refer to «REMOVAL»(ref-212815-S26161026662005122700000) ).
19. Remove the cylinder head access plug.
20. Remove the left side secondary chain guide (Refer to «REMOVAL»(ref-212815-S26161026662005122700000) ).
21. Remove the retaining bolt and the camshaft drive gear. CAUTION: Do not allow the engine to rotate. Severe damage to the valve train can occur. CAUTION: Do not overlook the four smaller bolts at the front of the cylinder head. Do not attempt to remove the cylinder head without removing these four bolts. NOTE: The cylinder head is attached to the cylinder block with fourteen bolts.
22. Remove the cylinder head retaining bolts.
23. Remove the cylinder head and gasket. Discard the gasket. CAUTION: Do not lay the cylinder head on its gasket sealing surface, due to the design of the cylinder head gasket any distortion to the cylinder head sealing surface may prevent the gasket from properly sealing resulting in leaks.

Scheme 184

Scheme 185

Scheme 186

Scheme 187

1. Disconnect battery negative cable.
2. Remove the wiper module (Refer to «MODULE-WINDSHIELD WIPER»(ref-212806-S16497299482005122700000) ).
3. Raise the vehicle on a hoist.
4. Disconnect the exhaust pipe at the right side exhaust manifold.
5. Drain the engine coolant (Refer to «DRAINING COOLING SYSTEM - ALL ENGINES»(ref-212747-S18408552002005122700000) ).
6. Lower the vehicle.
7. Remove the intake manifold (Refer to «REMOVAL»(ref-212815-S30348470442005122700000) ).
8. Remove the cylinder head cover (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,).
9. Remove the fan shroud (Refer to «FAN-RADIATOR VISCOUS»(ref-212747-S08435546542006072400000) ).
10. Remove oil fill housing from cylinder head.
11. Remove accessory drive belt (Refer to «BELTS-DRIVE»(ref-212748-S08533630352005122700000) ).
12. Rotate the crankshaft until the damper timing mark is aligned with TDC indicator mark.
13. Verify the V8 mark on the camshaft sprocket is at the 12 o'clock position. Rotate the crankshaft one turn if necessary.
14. Remove the crankshaft damper (Refer to «DAMPER-CRANKSHAFT»(ref-212815-S27538834182005122700000) ).
15. Remove the timing chain cover (Refer to «REMOVAL»(ref-212815-S12373249852005122700000) ).
16. Lock the secondary timing chains to the idler sprocket using Special Tool 8515. NOTE: Mark the secondary timing chain prior to removal to aid in installation.
17. Mark the secondary timing chain, one link on each side of the V8 mark on the camshaft drive gear.
18. Remove the right side secondary chain tensioner (Refer to «REMOVAL»(ref-212815-S26161026662005122700000) ).
19. Remove the cylinder head access plug.
20. Remove the right side secondary chain guide (Refer to «REMOVAL»(ref-212815-S26161026662005122700000) ).
21. Remove the retaining bolt and the camshaft drive gear. CAUTION: Do not allow the engine to rotate, severe damage to the valve train can occur. CAUTION: Do not overlook the four smaller bolts at the front of the cylinder head. Do not attempt to remove the cylinder head without removing these four bolts. CAUTION: Do not hold or pry on the camshaft target wheel for any reason. A damaged target wheel can result in a vehicle no start condition. NOTE: The cylinder head is attached to the cylinder block with fourteen bolts.
22. Remove the cylinder head retaining bolts.
23. Remove the cylinder head and gasket. Discard the gasket.

DESCRIPTION

The camshafts consist of powdered metal steel lobes which are sinter-bonded to a steel tube. A steel post or nose piece is friction-welded to the steel camshaft tube. Five bearing journals are machined into the camshaft, four on the steel tube and one on the steel nose piece. Camshaft end play is controlled by two thrust walls that border the nose piece journal. Engine oil enters the hollow camshafts at the third journal and lubricates every intake lobe rocker through a drilled passage in the intake lobe.

The camshafts consist of powdered metal steel lobes which are sinter-bonded to a steel tube. A steel post or nose piece is friction-welded to the steel camshaft tube. Five bearing journals are machined into the camshaft, four on the steel tube and one on the steel nose piece. Camshaft end play is controlled by two thrust walls that border the nose piece journal. Engine oil enters the hollow camshafts at the third journal and lubricates every intake lobe rocker through a drilled passage in the intake lobe.

The cylinder head covers are made of injection molded thermo-set plastic, and are not interchangeable from side-to-side. It is imperative that nothing rest on the cylinder head covers. Prolonged contact with other items may wear a hole in the cylinder head cover.

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.

The rocker arms are steel stampings with an integral roller bearing. The rocker arms incorporate a 2.8 mm (0.11 inch) oil hole in the lash adjuster socket for roller and camshaft lubrication.

The valve springs are made from high strength chrome silicon steel. The springs are common for intake and exhaust applications. The valve spring seat is integral with the valve stem seal, which is a positive type seal to control lubrication.

Scheme 188

1. Remove the cylinder head cover (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,).
2. Using Special Tool 8516 Rocker Arm Remover, remove the rocker arms and the hydraulic lash adjusters.
3. Remove the spark plug for the cylinder the valve spring and seal are to be removed from.
4. Apply shop air to the cylinder to hold the valves in place when the spring is removed
5. Remove the camshaft (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,). NOTE: All eight valve springs and seals are removed in the same manner; this procedure only covers one valve seal and valve spring.
6. Using Special Tool 8387 Valve Spring Compressor, compress the valve spring. NOTE: It may be necessary to tap the top of the valve spring to loosen the spring retainers locks enough to be removed.
7. Remove the two spring retainer lock halves. NOTE: the valve spring is under tension use care when releasing the valve spring compressor.
8. Remove the valve spring compressor.
9. Remove the spring retainer, and the spring.
10. Remove the valve stem seal.

Note. The valve stem seals are common between intake and exhaust.

Scheme 189

1. coat the valve stem with clean engine oil and install the valve stem seal. Make sure the seal is fully seated and that the garter spring at the top of the seal is intact.
2. Install the spring and the spring retainer.
3. Using Special Tool 8387 Valve Spring Compressor, compress the spring and install the two valve spring retainer halves.
4. Release the valve spring compressor and make sure the two spring retainer halves and the spring retainer are fully seated.
5. Install the camshaft (Refer to «INSTALLATION»(ref-212815-S41354626732005122700000) ,).
6. Position the hydraulic lash adjusters and rocker arms.
7. Install the cylinder head cover (Refer to «INSTALLATION»(ref-212815-S41354626732005122700000) ,).

The valve stem seals are made of rubber and incorporate an integral steel valve spring seat. The integral garter spring maintains consistent lubrication control to the valve stems.

The cylinder block is made of cast iron. The block is a closed deck design with the left bank forward. To provide high rigidity and improved NVH an enhanced compacted graphite bedplate is bolted to the block. The block design allows coolant flow between the cylinders bores, and an internal coolant bypass to a single poppet inlet thermostat is included in the cast aluminum front cover.

The crankshaft is constructed of nodular cast iron. The crankshaft is a crosshaped four throw design with eight counterweights for balancing purposes. The crankshaft is supported by five select fit main bearings with the number three serving as the thrust washer location. The main journals of the crankshaft are cross drilled to improve rod bearing lubrication. The number eight counterweight has provisions for crankshaft position sensor target wheel mounting. The select fit main bearing markings are located on the rear side of the target wheel. The crankshaft oil seals are one piece design. The front oil seal is retained in the timing chain cover, and the rear seal is pressed in to a bore formed by the cylinder block and the bedplate assembly.

The pistons are made of a high strength aluminum alloy. The anodized top ring groove and crown has been replaced with a coated top ring that is blue in color on the bottom surface. Piston skirts are coated with a solid lubricant (Molykote) to reduce friction and provide scuff resistance. The connecting rods are made of forged powdered metal, with a "fractured cap" design. A pressed fit piston pin is used to attach the piston and connecting rod.

Scheme 190

Scheme 191

1. To correctly select the proper size piston, a cylinder bore gauge, capable of reading in 0.003 mm ( .0001 in.) INCREMENTS is required. If a bore gauge is not available, do not use an inside micrometer.
2. Measure the inside diameter of the cylinder bore at a point 38.0 mm (1.5 inches) below top of bore. Start perpendicular (across or at 90 degrees) to the axis of the crankshaft at point A and then take an additional bore reading 90 degrees to that at point B.
3. The coated pistons will be serviced with the piston pin and connecting rod pre-assembled.
4. The coating material is applied to the piston after the final piston machining process. Measuring the outside diameter of a coated piston will not provide accurate results. Therefore measuring the inside diameter of the cylinder bore with a dial Bore Gauge is MANDATORY. To correctly select the proper size piston, a cylinder bore gauge capable of reading in 0.003 mm (.0001 in.) increments is required.
5. Piston installation into the cylinder bore requires slightly more pressure than that required for non-coated pistons. The bonded coating on the piston will give the appearance of a line-to-line fit with the cylinder bore.

Scheme 192

1. Disconnect negative cable from battery.
2. Remove the following components: Oil pan and gasket/windage tray (Refer to «REMOVAL»(ref-212815-S09016296762005122700000) ). Cylinder head covers (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,) and (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,). Timing chain cover (Refer to «REMOVAL»(ref-212815-S12373249852005122700000) ). Cylinder head(s) (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,) and (Refer to «REMOVAL»(ref-212815-S28311795922005122700000) ,).
3. If necessary, remove top ridge of cylinder bores with a reliable ridge reamer before removing pistons from cylinder block. Be sure to keep tops of pistons covered during this operation. Pistons and connecting rods must be removed from top of cylinder block. When removing piston and connecting rod assemblies from the engine, rotate crankshaft so the each connecting rod is centered in cylinder bore. CAUTION: DO NOT use a number stamp or a punch to mark connecting rods or caps, as damage to connecting rods could occur NOTE: Connecting rods and bearing caps are not interchangeable and should be marked before removing to ensure correct reassembly.
4. Mark connecting rod and bearing cap positions using a permanent ink marker or scribe tool. CAUTION: Care must be taken not to damage the fractured rod and cap joint face surfaces, as engine damage may occur.
5. Remove connecting rod cap. Install Special Tool 8507 Connecting Rod Guides into the connecting rod being removed. Remove piston from cylinder bore. Repeat this procedure for each piston being removed. CAUTION: Care must be taken not to nick crankshaft journals, as engine damage may occur
6. Immediately after piston and connecting rod removal, install bearing cap on the mating connecting rod to prevent damage to the fractured cap and rod surfaces.
7. Carefully remove piston rings from piston(s), starting from the top ring down.

The structural dust cover is made of die cast aluminum and joins the lower half of the transmission bell housing to the engine bedplate.

OPERATION

The structural cover provides additional powertrain stiffness and reduces noise and vibration.

Scheme 193

1. Raise vehicle on hoist.
2. Remove the left hand exhaust pipe from exhaust manifold.
3. Loosen the right hand exhaust manifold-to-exhaust pipe retaining bolts.
4. Remove the eight bolts retaining structural cover in the sequence shown.
5. Pivot the exhaust pipe downward and remove the structural cover.

Oil from the oil pan is pumped by a gerotor type oil pump directly mounted to the crankshaft nose. Oil pressure is controlled by a relief valve mounted inside the oil pump housing. For lubrication flow refer to.

The camshaft exhaust valve lobes and rocker arms are lubricated through a small hole in the rocker arm; oil flows through the lash adjuster then through the rocker arm and onto the camshaft lobe. Due to the orientation of the rocker arm, the camshaft intake lobes are not lubed in the same manner as the exhaust lobes. The intake lobes are lubed through internal passages in the camshaft. Oil flows through a bore in the number 3 camshaft bearing bore, and as the camshaft turns, a hole in the camshaft aligns with the hole in the camshaft bore allowing engine oil to enter the camshaft tube. The oil then exits through 1.6mm (0.063 in.) holes drilled into the intake lobes, lubricating the lobes and the rocker arms.

CONTAINER IDENTIFICATION

Standard engine oil identification notations have been adopted to aid in the proper selection of engine oil. The identifying notations are located on the label of engine oil; plastic bottles and the top of engine oil cans.

Scheme 194

The 3-wire, electrical/mechanical engine oil pressure sensor (sending unit) is located in an engine oil pressure gallery.

The oil pressure sensor uses two circuits. They are

1. A signal to the PCM relating to engine oil pressure
2. A sensor ground through the PCM's sensor return

The oil pressure sensor returns a voltage signal back to the PCM relating to engine oil pressure. This signal is then transferred (bussed) to the instrument panel on a CCD bus circuit to operate the oil pressure gauge and the check gauges lamp. Ground for the sensor is provided by the PCM through a low-noise sensor return.

Scheme 195

1. Disconnect the negative cable from the battery.
2. Raise vehicle on hoist.
3. Remove front splash shield.
4. Disconnect oil pressure sender wire.
5. Remove the pressure sender.

The intake manifold is made of a composite material and features long runners which maximizes low end torque. The intake manifold uses single plane sealing which consist of eight individual press in place port gaskets to prevent leaks. Eight studs and two bolts are used to fasten the intake to the head.

The exhaust manifolds are log style with a patented flow enhancing design to maximize performance. The exhaust manifolds are made of high silicon molybdenum cast iron. A perforated core graphite exhaust manifold gasket is used to improve sealing to the cylinder head. The exhaust manifolds are covered by a three layer laminated heat shield for thermal protection and noise reduction. The heat shields are fastened with a torque prevailing nut that is backed off slightly to allow for the thermal expansion of the exhaust manifold.

Scheme 196

1. Disconnect negative cable for battery.
2. Remove air cleaner assembly, resonator assembly and air inlet hose.
3. Remove accessory drive belt (Refer to «BELTS-DRIVE»(ref-212748-S08533630352005122700000) ).
4. Remove A/C compressor (Refer to «COMPRESSOR-A/C»(ref-212855-S21919888982005122700000) ).
5. Remove A/C accumulator support bracket fastener.
6. Drain coolant below heater hose level (Refer to «DRAINING COOLING SYSTEM - ALL ENGINES»(ref-212747-S18408552002005122700000) ).
7. Remove heater hoses at engine.
8. Remove fasteners attaching exhaust manifold heat shield.
9. Remove heat shield.
10. Remove upper exhaust manifold attaching fasteners.
11. Raise vehicle on hoist.
12. Disconnect exhaust pipe from manifold.
13. Remove fasteners attaching starter. Move starter aside.
14. Remove lower exhaust manifold attaching fasteners.
15. Remove exhaust manifold and gasket. Manifold is removed from below the engine compartment.

Scheme 197

1. Disconnect negative cable for battery.
2. Hoist vehicle.
3. Disconnect exhaust pipe at manifold.
4. Lower vehicle.
5. Remove the front two exhaust heat shield retaining fasteners. Raise vehicle and remove the fasteners at rear of heat shield.
6. Remove heat shield.
7. Lower vehicle and remove the upper exhaust manifold retaining bolts.
8. Raise vehicle and remove the lower exhaust manifold retaining bolts.
9. Remove exhaust manifold and gasket. Manifold is removed from below the engine compartment.

OPERATION - TIMING DRIVE SYSTEM

The primary timing chain is a single inverted tooth type. The primary chain drives the large fifty tooth idler sprocket directly from a 25 tooth crankshaft sprocket. Primary chain motion is controlled by a pivoting leaf spring tensioner arm and a fixed guide. The arm and the guide both use nylon plastic wear faces for low friction and long wear. The primary chain receives oil splash lubrication from the secondary chain drive and oil pump leakage. The idler sprocket assembly connects the primary and secondary chain drives. The idler sprocket assembly consists of two integral thirty tooth sprockets and a fifty tooth sprocket that is splined to the assembly. The spline joint is a non - serviceable press fit anti rattle type. The idler sprocket assembly spins on a stationary idler shaft. The idler shaft is press-fit into the cylinder block. A large washer on. the idler shaft bolt and the rear flange of the idler shaft are used to control sprocket thrust movement. Pressurized oil is routed through the center of the idler shaft to provide lubrication for the two bushings used in the idler sprocket assembly.

There are two secondary drive chains, both are inverted tooth type, one to drive the camshaft in each SOHC cylinder head. There are no shaft speed changes in the secondary chain drive system. Each secondary chain drives a thirty tooth cam sprocket directly from the thirty tooth sprocket on the idler sprocket assembly. A fixed chain guide and a hydraulic oil damped tensioner are used to maintain tension in each secondary chain system. The hydraulic tensioners for the secondary chain systems are fed pressurized oil from oil reservoir pockets in the block. Each tensioner also has a mechanical ratchet system that limits chain slack if the tensioner piston bleeds down after engine shut down. The tensioner arms and guides also utilize nylon wear faces for low friction and long wear. The secondary timing chains receive lubrication from a small orifice in the tensioners. This orifice is protected from clogging by a fine mesh screen which is located on the back of the hydraulic tensioners.