Overhaul - 3.5L Engine: Overview Chrysler Pacifica CS

Scheme 26

The 3.5 Liter (214 Cubic Inches) 60 degree V-6 engine is a single overhead camshaft design with hydraulic lifters and four valves per cylinder. (Scheme 26) The engine does not have provisions for a free wheeling valve train.

The cylinders are numbered from front to rear, with the right bank odd numbered, and the left bank even numbered. (Scheme 27) The firing order is 1-2-3-4-5-6.

The engine identification number is located on the rear of engine block just below the left cylinder head. (Scheme 28)

Scheme 27

Scheme 28

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 mechanical (e.g, a strange noise), or performance (e.g, engine idles rough and stalls).

Refer to DIAGNOSIS AND TESTING - ENGINE MECHANICAL and DIAGNOSIS AND TESTING - ENGINE PERFORMANCE Chart for possible causes and corrections of malfunctions. Refer to FUEL SYSTEM for the fuel system diagnosis.

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

1. Cylinder Compression Pressure Test
2. Cylinder Combustion Pressure Leakage Test
3. Cylinder Head Gasket Failure Diagnosis
4. Intake Manifold Leakage Diagnosis
5. Lash Adjuster (Tappet) Noise Diagnosis
6. Engine Oil Leak Inspection

DESCRIPTION

The aluminum alloy cylinder heads feature cross- flow type intake and exhaust ports. Valve guides and seat inserts are powdered metal. Valves are arranged in a "V", with each camshaft on center. To improve combustion speed the chambers are a compact spherical design with a squish area of approximately 30 percent of the piston top area. The cylinder heads are common to either cylinder bank by reversing the direction of installation.

A single overhead camshaft per cylinder head provides valve actuation. The left camshaft accommodates a cam sensor pick-up wheel and is therefore longer. Each camshaft is supported by four bearing journals. A thrust plate attached to the rear of each cylinder head controls camshaft end play. Right and left camshaft driving sprockets support a timing mark, are keyed, and not interchangeable because of the cam sensor pick-up wheel on the left sprocket. Camshaft bearing lubrication is provided via a oil supply passage through each rocker shaft pedestal dowel.

OPERATION

The camshaft is driven by the crankshaft via drive sprockets and belt. The camshaft has precisely machined lobes to provide accurate valve timing and duration.

Valves are made of highly heat-resistant steel and are chrome plated to prevent stem scuffing. The intake valve is a one-piece forging, while the exhaust valve has a forged head with a welded stem for lock groove hardenability. The four valves (two intake and two exhaust) employ a three-groove lock design to help facilitate valve rotation.

The intake valve allows the air/fuel mixture to enter the combustion chamber. The exhaust valve allows the burned air/fuel mixture to exit the combustion chamber. Also, the intake and exhaust valves seal the combustion chamber during the compression and power strokes.

DESCRIPTION - ROCKER ARM

Rocker arms are made of light weight permanent mold aluminum alloy with a roller type follower operating against the camshaft. (Scheme 30) The valve actuating end of the rocker arms are machined to retain hydraulic lash adjusters, eliminating the need for manual valve lash adjustment.

Scheme 29

DESCRIPTION - ROCKER ARM SHAFTS

The rocker arm shafts. see scheme 78are tubular steel and are supported by several forged aluminum alloy pedestals, which are fastened to the cylinder head. Four shafts are used, one for each intake and exhaust rocker arm bank on each cylinder head. The shafts are hollow to provide a duct for lubricating oil flow from the cylinder head to the valve mechanisms. One hollow dowel per pedestal is used to locate the pedestal to the cylinder head, orient the exhaust rocker shaft, and serve as a cam bearing oil feed passage.

Scheme 30

The rocker arm is the pivot point between the camshaft lobe and the valve.

The valve spring returns the valve against its seat for a positive seal of the combustion chamber.

The cylinder block. see scheme 98is 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.

Scheme 31

The crankshaft is constructed of a forged micro alloy steel. A six throw, nine counterweight crankshaft is supported by four select fit main bearings with number two serving as the thrust washer location. The six separate connecting rod throws are an even-firing design which reduces torque fluctuations while a torsional vibration damper is used to control torsion caused vibration of the crankshaft. Rubber lipped seals are used at front and rear. The front seal is retained in the oil pump case and the rear seal is retained in a block-mounted housing.

The crankshaft transfers force generated by combustion within the cylinder to the flywheel or flexplate.

Scheme 32

Scheme 33

1. Remove engine from vehicle (Refer to «REMOVAL»(ref-245454-S34220342432006110200000) ).
2. Remove oil pan (Refer to «OIL PAN»(ref-245454-S38346867822006110200000) ).
3. Remove oil pickup tube and windage tray. (Scheme 33) 1 - OIL PICK UP TUBE 2 - SEAL 3 - WINDAGE TRAY
4. Remove front timing belt cover (Refer to «FRONT TIMING BELT COVER»(ref-245454-S03005879422006110200000) ).
5. Remove timing belt and tensioner (Refer to «TIMING BELT AND SPROCKETS»(ref-245454-S01103536842006110200000) ).
6. Remove crankshaft sprocket (Refer to «TIMING BELT AND SPROCKETS»(ref-245454-S01103536842006110200000) ).
7. Tap dowel pin out of crankshaft.
8. Remove oil pump assembly (Refer to «OIL PUMP»(ref-245454-S20984439722006110200000) ).
9. Remove crankshaft rear oil seal retainer. (Scheme 34) 1 - REAR OIL SEAL AND RETAINER ASSEMBLY 2 - BOLT 3 - ALIGNMENT DOWEL
10. Remove connecting rod bearing caps. Connecting rod bearing caps are not interchangeable and should be paint marked or scribed before removal to insure correct assembly. (Scheme 35) see scheme 107
11. Remove main bearing caps. Main bearing caps are not interchangeable and are marked to insure correct assembly. (Scheme 36) see scheme 107
12. Remove crankshaft from cylinder block. see scheme 107

Note. Before installing crankshaft, refer to . (Refer to STANDARD PROCEDURE - CRANKSHAFT MAIN BEARING FITTING ) (Refer to STANDARD PROCEDURE - CONNECTING RODS AND BEARINGS ).

Scheme 34

Scheme 35

Scheme 36

The pistons are made of a high strength aluminum alloy. Top land height has been decreased to reduce emissions. Piston skirts are coated with a solid lubricant for scuff resistance. Connecting rod is forged steel with a fractured connecting rod cap design. The connecting rod is also equipped with a squirt hole and attaches to the piston with a full floating pin retained by lock rings.

The piston and connecting rod assembly is the link between the combustion force and the crankshaft.

The piston rings include a moly-filled top ring with a symmetrical barrel face. The intermediate piston ring is of the standard chrome design OR Micro-Napier design. The Micro-Napier design has a reduced "hook" on the running face, removes the need for chroming and improves oil economy. The oil control package consists of two steel rails and an expander spacer. see scheme 132

Scheme 37

Scheme 38

Scheme 39

1. Wipe cylinder bore clean. Insert ring and push down with piston to ensure it is square in bore. The ring gap measurement must be made with the ring positioning at least 12 mm (0.50 in.) from bottom of cylinder bore. Check gap with feeler gauge. see scheme 133 For clearance specifications, (Refer to «SPECIFICATIONS»(ref-245454-S19893092512006110200000) ). 1 - FEELER GAUGE 1 - FEELER GAUGE
2. Check piston ring to groove clearance:. see scheme 134 For clearance specifications, (Refer to «SPECIFICATIONS»(ref-245454-S19893092512006110200000) ).

The engine mounting system are of molded rubber material and consist of three mounts; right and a left side support the powertrain, and a front mount control powertrain torque.

Scheme 40

1. Support engine assembly with a floor jack so it will not rotate.
2. Remove the air cleaner element housing (Refer to «HOUSING-AIR CLEANER»(ref-245454-S16653029582006110200000) ).
3. Remove the upper engine mount bolts from the inner frame rail. see scheme 142
4. Remove the upper engine mount bolts from the engine. see scheme 142

The oil lubrication system. see scheme 148is a full-flow filtration, pressure feed type. The oil pump body is mounted to the engine block. The pump inner rotor is driven by the crankshaft. A windage tray, increases power by minimizing oil windage at high engine RPM. For increased oil cooling, an oil-to-coolant oil cooler is used.

Scheme 41

Engine oil stored in the oil pan is drawn in and discharged by a gerotor type oil pump. The oil pump is directly coupled to the crankshaft. Oil pressure is regulated by a relief valve. The oil is fed through an oil filter and to the crankshaft journals from the oil gallery in the cylinder block. This gallery also feeds oil under pressure to the cylinder heads. Oil flows through each cylinder heads oil passage to the rocker shafts. Oil then feeds the camshaft journals, rocker arms, and hydraulic lash adjusters. see scheme 149

For engine oil type and capacity (Refer to LUBRICATION & MAINTENANCE/FLUID TYPES - DESCRIPTION - ENGINE OIL) .

The engine oil cooler is a coolant-to-oil type and is mounted between the oil filter and the oil filter adapter. see scheme 153

Engine oil travels from the oil cooler and into the oil filter. Engine oil then exits the filter into the main gallery. Engine coolant flows into the cooler from the heater return tube and exits into the water inlet tube.

The timing drive system has been designed to provide quiet performance and reliability to support a NON free-wheeling engine.

The timing drive components include a crankshaft sprocket, camshaft sprockets, tensioner pulley, hydraulic tensioner and a timing belt. The water pump is driven by the back side of the timing belt. The right and left camshaft sprockets are keyed and not interchangeable because of the cam sensor pick-up wheel on the left sprocket. see scheme 189

Scheme 42

Scheme 43

1. Perform fuel pressure release procedure. «(Refer to FUEL SYSTEM/FUEL DELIVERY - STANDARD PROCEDURE)»(ref-245444-S24174060702006110200000).
2. Disconnect negative battery cable.
3. Raise vehicle on hoist.
4. Remove accessory drive belt «(Refer to COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL)»(ref-245448-S38168346922006110200000).
5. Remove accessory drive belt tensioner.
6. Remove bolts for power steering pump. Reposition power steering pump aside.
7. Remove crankshaft damper (Refer to «VIBRATION DAMPER»(ref-245454-S23796174082006110200000) ).
8. Remove the lower front timing belt cover fasteners. see scheme 190 1 - POWER STEERING HOSE 2 - TIMING BELT TENSIONER 3 - IDLER PULLEY
9. Lower the vehicle.
10. Support the engine with a floor jack.
11. Remove the air cleaner housing (Refer to «HOUSING-AIR CLEANER»(ref-245454-S16653029582006110200000) ).
12. Remove the front engine mount «(Refer to ENGINE/ENGINE MOUNTING/FRONT MOUNT - REMOVAL)»(ref-245454-S42022234272006110200000).
13. Disconnect the fuel supply line at the fuel rail. see scheme 191
14. Remove the upper timing belt cover bolts and remove front timing belt cover (Refer to «HOUSING-AIR CLEANER»(ref-245454-S16653029582006110200000) ).

Scheme 44