compression ratio CHRYSLER TOWN AND COUNTRY 2002 User Guide

CONDITION POSSIBLE CAUSE CORRECTION
ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap.
2. Contamination in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each
cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust
system.8. Perform exhaust restriction test.
(Refer to 11 - EXHAUST SYSTEM -
DIAGNOSIS AND TESTING) Install
new parts, as necessary.
9. Faulty ignition coil(s). 9. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES ON
ACCELERATION1. Dirty or incorrectly gapped spark
plugs.1. Clean spark plugs and set gap.
2. Contamination in Fuel System. 2. Clean fuel system and replace
fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty ignition coil(s). 4. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES AT HIGH SPEED 1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap.
2. Faulty ignition coil(s). 2. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
3. Dirty fuel injector(s). 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
4. Contamination in fuel system. 4. Clean system and replace fuel
filter.
RSENGINE 3.3/3.8L9-79
ENGINE 3.3/3.8L (Continued)
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SPECIFICATIONS
3.3/3.8L ENGINE
DESCRIPTION SPECIFICATION
General Specification
Type 60É V-6 Engine
Number of Cylinders 6
Displacement
Ð3.3L 3.3 Liters
(201 cu. in.)
Ð3.8L 3.8 Liters
(231 cu. in.)
Bore
Ð3.3L 93.0 mm
(3.66 in.)
Ð3.8L 96.0 mm
(3.779 in.)
Stroke
Ð3.3L 81.0 mm
(3.188 in.)
Ð3.8L 87.0 mm
(3.425 in.)
Compression Ratio
Ð3.3L 9.35:1
Ð3.8L 9.6:1
Firing Order 1-2-3-4-5-6
Cylinder Number (Front
to Rear)
ÐFront Bank 2,4,6
ÐRear Bank 1,3,5
Compression PressureÐ
Minimum689.5 kPa
(100 psi)
Max. Variation Between
Cylinders25%
Cylinder Block
Cylinder Bore Diameter
(Standard)
Ð3.3L 92.993±93.007 mm
(3.661±3.6617 in.)
Ð3.8L 95.993±96.007 mm
(3.7792±3.780 in.)
DESCRIPTION SPECIFICATION
Out-of-Round (Service
Limits)0.076 mm
(0.003 in.)
Taper (Service Limits) 0.051 mm
(0.002 in.)
Lifter Bore Diameter 22.980±23.010 mm
(0.905±0.906 in.)
Deck Surface Flatness
(Max.)0.1 mm
(0.004 in.)
Pistons
Piston Diameter
Ð3.3L ÐMeasured 39.8
mm (1.567 in.) from
piston top92.968±92.998 mm
(3.660±3.661 in.)
Ð3.8L ÐMeasured 33.01
mm (1.30 in.) from piston
top95.968±95.998 mm
(3.778±3.779 in.)
Clearance in Bore @
Size Location (New)-0.005±0.039 mm
(-0.0002±0.0015 in.)
Weight
Ð3.3L 362  5 grams
(12.77  0.1764 oz.)
Ð3.8L 426  5 grams
(15.03  0.1764 oz.)
Piston Pins
Type Press Fit in Rod
(Serviced as an
Assembly)
Clearance in Piston @
21É C (70É F)0.006±0.019 mm
(0.0002±0.0007 in.)
Clearance in Connecting
Rod(Interference Fit)
Diameter 22.87±22.88 mm
(0.9007±0.9009 in.)
Length
Ð3.3L 67.25±67.75 mm
(2.648±2.667 in.)
Ð3.8L 71.25±71.75
(2.805±2.824 in.)
Piston Rings
Ring End GapÐTop
Compression Ring0.18±0.38 mm
(0.007±0.015 in.)
Wear Limit 1.0 mm
(0.039 in.)
9 - 92 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)
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INSTALLATION
(1) Install air box into vehicle and onto the locat-
ing pin.
(2) Install bolt to hold air box to the upper radia-
tor cross member.
(3) Install the inlet hose to the throttle body.
(4) Connect the inlet air temperature sensor (Fig.
16).
(5) Connect the negative battery cable.
CYLINDER HEAD
DESCRIPTION
The aluminum cylinder heads (Fig. 17) are
designed to create high flow combustion chambers to
improve performance, while minimizing the change
to the burn rate in the chamber. The cylinder head
incorporates the combustion chamber. Two valves
per-cylinder are used with inserted valve seats and
guides. A multi-layer steel (MLS) type gasket is used
between the cylinder head and engine block.
OPERATION
The cylinder head closes the combustion chamber,
allowing the pistons to compress the fuel/air mixture
for ignition. The valves are actuated by the lobe pro-
files on the camshaft to open and close at specified
duration to either allow clean air in the combustion
chamber or the exhaust gases out; depending on the
stroke of the engine.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50±70%
reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL - CYLINDER HEAD
(1) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(2) Disconnect negative cable from battery.
(3) Remove upper and lower intake manifolds.
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-
FOLD - REMOVAL)
WARNING: INTAKE MANIFOLD GASKET IS MADE
OF VERY THIN METAL AND MAY CAUSE PER-
SONAL INJURY, HANDLE WITH CARE.
9 - 100 ENGINE 3.3/3.8LRS
AIR CLEANER HOUSING (Continued)
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the plunger and the lifter body causing the plunger
to stick in the down position. This heavy click will be
accompanied by excessive clearance between the
valve stem and rocker arm as valve closes. In either
case, lifter assembly should be removed for inspec-
tion.
REMOVAL
(1) Remove the cylinder head(s). (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL)
(2) Remove the yoke retainer and aligning yokes
(Fig. 73).
(3) Remove the hydraulic lifters. If necessary use
Special Tool C-4129, or equivalent to remove lifters
from bores. If lifters are to be reused, identify each
lifter to ensure installation in original location.
INSTALLATION
(1) Lubricate the lifters with engine oil.
NOTE: Position the lifter in bore with the lubrication
hole facing upward (Fig. 72).
(2) Install the hydraulic lifters with the lubrication
hole facing upward towards middle of block (Fig. 72).
Install lifters in original positions, if reused.
(3) Install lifter aligning yokes (Fig. 73).
(4) Install yoke retainer and torque screws to 12
N´m (105 in. lbs.) (Fig. 73).
(5) Install the cylinder heads. (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION)
(6) Start and operate engine. Warm up to normal
operating temperature.
CAUTION: To prevent damage to valve mechanism,
engine must not be run above fast idle until allhydraulic lifters have filled with oil and have
become quiet.
PISTON & CONNECTING ROD
DESCRIPTION
The pistons are made of cast aluminum alloy and
are a strutless, short skirt design. The piston rings
consist of two compression rings and a three piece oil
ring. Piston pins connect the piston to the forged
steel connecting rods. The piston pins are a press fit
into the connecting rod.
OPERATION
The piston and connecting rod is the link between
the combustion force to the crankshaft.
Fig. 72 LIFTER LUBRICATION HOLE
Fig. 73 Lifter Aligning Yoke and Retainer
1 - YOKE RETAINER
2 - BOLT - YOKE RETAINER
3 - ALIGNING YOKE
4 - HYDRAULIC LIFTER
9 - 126 ENGINE 3.3/3.8LRS
HYDRAULIC LIFTERS (CAM IN BLOCK) (Continued)
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(5) Inspect connecting rods and connecting rod
caps for cylinder identification. Identify them, if nec-
essary (Fig. 78).
(6) Remove connecting rod cap. Install connecting
rod bolt protectors on connecting rod bolts (Fig. 79).
(7) Remove each piston and connecting rod assem-
bly out of the cylinder bore.
NOTE: Be careful not to nick crankshaft journals.
(8) After removal, install bearing cap on the mat-
ing rod.
INSTALLATION
(1) Before installing pistons and connecting rod
assemblies into the bore, ensure that compression
ring gaps are staggered so that neither is in line with
oil ring rail gap (Fig. 80).(2) Before installing the ring compressor, ensure
the oil ring expander ends are butted and the rail
gaps located as shown in (Fig. 80).
(3) Lubricate the piston and rings with clean
engine oil. Position a ring compressor over the piston
and rings, and tighten the compressor (Fig. 81).Be
sure position of rings does not change during
this operation.
(4) Position upper bearing onto connecting rod.
Lubricate bearing with oil.
(5) Install connecting rod bolt protectors (rubber
hose or equivalent) on the connecting rod bolts (Fig.
81).
Fig. 77 Checking Cylinder Bore Size
Fig. 78 Identify Connecting Rod to Cylinder
1 - CYLINDER NUMBER
Fig. 79 Connecting Rod Protectors
1 - COVER ROD BOLTS WITH A SUITABLE COVERING WHEN
REMOVING OR INSTALLING PISTON ASSEMBLY
Fig. 80 Piston Ring End Gap Position
1 - SIDE RAIL UPPER
2 - NO. 1 RING GAP
3 - PISTON PIN
4 - SIDE RAIL LOWER
5 - NO. 2 RING GAP AND SPACER EXPANDER GAP
9 - 128 ENGINE 3.3/3.8LRS
PISTON & CONNECTING ROD (Continued)
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(3) Position heat shield on manifold (Fig. 136).
(4) Install the remaining manifold attaching bolts.
Tighten all bolts to 23 N´m (200 in. lbs.).
(5) Install and tighten heat shield attaching nut to
12 N´m (105 in. lbs.) (Fig. 136).
(6) Connect battery negative cable.
VALVE TIMING
STANDARD PROCEDURE
STANDARD PROCEDURE - VALVE TIMING
VERIFICATION
(1) Remove front cylinder head cover and all 6
spark plugs.
(2) Rotate engine until the #2 piston is at TDC of
the compression stroke.
(3) Install a degree wheel on the crankshaft pulley.
(4) With proper adaptor, install a dial indicator
into #2 spark plug hole. Using the indicator find TDC
on the compression stroke.
(5) Position the degree wheel to zero.
(6) Remove dial indicator from spark plug hole.
(7) Place a 5.08 mm (0.200 in.) spacer between the
valve stem tip of #2 intake valve and rocker arm pad.
Allow tappet to bleed down to give a solid tappet
effect.
(8) Install a dial indicator so plunger contacts the
#2 intake valve spring retainer as nearly perpendic-
ular as possible. Zero the indicator.
(9) Rotate the engine clockwise until the intake
valve has lifted .254 mm (0.010 in.).
CAUTION: Do not turn crankshaft any further clock-
wise as intake valve might bottom and result in
serious damage.
(10) Degree wheel should read 6 degrees BTDC to
6 degrees ATDC.
STANDARD PROCEDURE - MEASURING
TIMING CHAIN WEAR
NOTE: This procedure must be performed with the
timing chain cover removed (Refer to 9 - ENGINE/
VALVE TIMING/TIMING CHAIN COVER - REMOVAL).
(1) Position a scale next to timing chain so that
any movement of chain may be measured (Fig. 138).
(2) Position a torque wrench and socket on the
camshaft sprocket attaching bolt. Apply force in the
direction of crankshaft rotation to take up slack to
the following torque:
²41 N´m (30 ft. lb.) with cylinder heads installed
²20 N´m (15 ft. lb.) with cylinder heads removedNOTE: With torque applied to the camshaft
sprocket bolt, crankshaft should not be permitted to
move. It may be necessary to block crankshaft to
prevent rotation.
(3) Holding a measuring scale along edge of chain
links (Fig. 138).
(4) Apply force in the reverse direction to the fol-
lowing torque:
²41 N´m (30 ft. lb.) with cylinder heads installed
²20 N´m (15 ft. lb.) with cylinder heads removed
(5) Measure amount of sprocket/chain movement.
(6) Install a new timing chain and sprockets if
movement exceeds 3.175 mm (1/8 in.).
TIMING CHAIN COVER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(3) Raise vehicle on hoist.
(4) Drain engine oil.
(5) Remove right wheel and inner splash shield.
(6) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
(7) Remove oil pick-up tube (Fig. 139).
(8) Remove accessory drive belt. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(9) Remove A/C compressor and set aside.
(10) Remove crankshaft vibration damper. (Refer
to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(11) Remove radiator lower hose.
Fig. 138 Measuring Timing Chain Wear
1 - TORQUE WRENCH
RSENGINE 3.3/3.8L9 - 155
EXHAUST MANIFOLD - LEFT (Continued)
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INSTALLATION
INSTALLATION.......................47
INSTALLATION.......................48
OIL PRESSURE SENSOR/SWITCH
DESCRIPTION.........................48
REMOVAL.............................48
INSTALLATION.........................48
OIL TEMPERATURE SENSOR
DESCRIPTION.........................48
REMOVAL.............................48
INSTALLATION.........................48
OIL PRESSURE RELIEF VALVE
DESCRIPTION.........................49
REMOVAL.............................49
INSTALLATION.........................49
OIL COOLER & LINES
REMOVAL.............................50
INSTALLATION.........................50
OIL FILTER
DESCRIPTION.........................51
REMOVAL.............................51
INSTALLATION.........................51
OIL JET
DESCRIPTION.........................52
REMOVAL.............................52
INSTALLATION.........................52
INTAKE MANIFOLD
DESCRIPTION.........................52
REMOVAL.............................52INSTALLATION.........................52
VALVE TIMING
STANDARD PROCEDURE - LOCKING ENGINE
90É AFTER TDC.......................53
BALANCE SHAFT
DESCRIPTION.........................54
OPERATION...........................54
REMOVAL.............................55
INSTALLATION.........................55
TIMING BELT / CHAIN COVER(S)
REMOVAL
REMOVAL - TIMING BELT OUTER COVER . . 56
REMOVAL - TIMING BELT INNER COVER . . . 56
INSTALLATION
INSTALLATION - TIMING BELT OUTER
COVER.............................56
INSTALLATION - TIMING BELT INNER
COVER.............................57
TIMING BELT IDLER PULLEY
REMOVAL.............................58
INSTALLATION.........................58
TMNG BELT/CHAIN TENSIONER
REMOVAL.............................59
INSTALLATION.........................59
ADJUSTMENTS
ADJUSTMENT - TIMING BELT TENSIONER . 60
TIMING BELT/CHAIN AND SPROCKETS
REMOVAL.............................60
INSTALLATION.........................61
ENGINE 2.5L TURBO DIESEL
DESCRIPTION
DESCRIPTION - 2.5L COMMON RAIL DIESEL
ENGINE
This 2.5 Liter (2500cc) four-cylinder ªcommon railº
direct injection engine is an in-line overhead valve
diesel engine. This engine utilizes a cast iron cylin-
der block and an aluminum cylinder head. The
engine is turbocharged and intercooled. The engine
also has four valves per cylinder and dual overhead
camshafts (Fig. 1).
DESCRIPTION SPECIFICATION
Displacement 2.5L (2499 cc)
Bore 92.00
Stroke 94.00
Compression Ratio 17.5:1
Vacuum at Idle 685.8 mm/Hg (27.0
In/Hg)
Belt Tension Automatic Belt Tensioner
DESCRIPTION SPECIFICATION
Thermostat Opening 80ÉC   2ÉC
Generator Rating Denso 12V-95A
Cooling System Capacity 13.8 Liters W/O Auxiliary
Heater
16.6 Liters With Auxiliary
Heater
Engine Oil Capacity 6.0L W/Filter Change
Timing System Belt Driven Camshafts In
Cylinder Head Cover
Air Intake Dry Filter
Fuel Feed Vane Pump Incorporated
In Injection Pump
Fuel System Direct Fuel Injection
Combustion Cycle 4 Stroke
Cooling System Water Cooling
Injection Pump Rotary Pump and
Electronically Managed
Lubrication Pressure Lubricated By
Rotary Pump
Engine Rotation Clockwise Viewed From
Front Cover
9a - 2 ENGINERG
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SPECIFICATIONS
SPECIFICATIONS - 2.5L COMMON RAIL
DIESEL ENGINE
ENGINE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Type R2516C
Number of Cylinders 4
Bore 92 mm
Stroke 94 mm
Displacement 2499.5cc
Injection Order 1-3-4-2
Compression Ratio 17.5:1 (  0.5)
Maximum Power 103kW (140 HP) @ 4000
RPM
Peak Torque 320Nm (32.6 kgm) @
2000 RPM
CRANKSHAFT
Front Journal Diameter
Nominal 62.985-63.005 mm
-0.25 62.735-62.755 mm
Front Bearing Diameter
Nominal 63.045-63.074 mm
-0.25 62.795-62.824 mm
Clearance Between
Journal and Bearing0.040-0.089 mm
Center Journal Diameter
Nominal 63.005-63.020 mm
-0.25 62.755-62.770 mm
Center Bearing Diameter
Nominal 63.005-63.020 mm
-0.25 62.755-62.770 mm
Clearance Between
Journal and Bearing0.008-0.051 mm
Rear Journal Diameter
Nominal 89.980-90.000 mm
-0.25 89.730-99.750 mm
Rear Bearing Diameter
Nominal 90.045-90.065 mm
-0.25 89.795-89.815 mm
Clearance Between
Journal and Bearing0.045-0.080 mm
Connecting Rod Journal
Nominal 53.940-53.955 mm
DESCRIPTION SPECIFICATION
-0.25 53.690-53.705 mm
Connecting Rod Bearing
Nominal 53.977-54.016 mm
-0.25 53.727-53.766 mm
Clearance Between
Journal and Bearing0.022-0.076 mm
Crankshaft End Play
End Play 0.080-0.280 mm
Adjustment Thrust Washers
Thrust Washers Available 2.31-2.36 mm
2.41-2.46 mm
2.51-2.56 mm
Carrier with thrust
washers installed27.670-27.820 mm
MAIN BEARING CARRIERS
Internal Diameter
Front 67.025-67.050 mm
Center 66.670-66.690 mm
Rear 85.985-86.005 mm
LINERS
Internal Diameter 91.997-92.015 mm
Protrusion 0.01-0.06 mm
Adjustment Shims
Available Shims 0.15 mm
0.17 mm
0.20 mm
0.23 mm
0.25 mm
CYLINDER HEAD
Minimum Thickness 89.95-90.05 mm
Gasket Thickness 1.32 mm   0.08, 0
notches
1.42 mm   0.08, 1 notch
1.52 mm   0.08, 2
notches
CONNECTING RODS
Weight (without the
crankbearing)1129-1195 grams
Small End Bearing
Internal Diameter30.035-30.050 mm
Large End Internal
Diameter53.977-54.016 mm
9a - 8 ENGINERG
ENGINE 2.5L TURBO DIESEL (Continued)
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assembly, determined by the numbers stamped on
the crown of individual pistons. Engine cylinders are
numbered starting from gear train end of the engine.
Face arrow on top of piston toward front of
engine. Therefore, the numbers stamped on connect-
ing rod big end should face toward the injection
pump side of engine. To insert piston into cylinder
use a ring compressor (VM.1065) as shown in (Fig.
57).
INSTALLATION
(1) Before installing pistons, and connecting rod
assemblies into the bore, be sure that compression
ring gaps are staggered so that neither is in line with
oil ring rail gap (Fig. 56).
(2) Before installing the ring compressor, make
sure the oil ring expander ends are butted together.
(3) Immerse the piston head and rings in clean
engine oil, slide the ring compressor, over the piston
and tighten (Fig. 57).Ensure position of rings
does not change during this operation.
NOTE: Be sure arrow on top of piston faces
towards front of engine.
NOTE: Be careful not to nick crankshaft journals.
(4) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore. Insert
rod and piston into cylinder bore and guide rod over
the crankshaft journal.(5) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on connecting rod journal.
(6) Install connecting rod caps (Fig. 58). Install rod
bolts and tighten to 30N´m (22 ft.lb.) plus 60É. Then
torque to 88N´m (65 ft.lb).
(7) Install cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - INSTALLATION).
(8) Install balance shaft assembly (Refer to 9 -
ENGINE/VALVE TIMING/BALANCE SHAFT -
INSTALLATION).
(9) Install oil pump pickup tube (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP - INSTALLA-
TION).
(10) Install oil pan (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - INSTALLATION).
(11) Connect negative battery cable.
Fig. 57 PISTON INSTALLATION USING VM.1065
Fig. 58 PISTON AND CONNECTING ROD
INSTALLATION
1 - PISTON AND CONNECTING ROD ASSEMBLY
2 - FOUR DIGIT NUMBER
3 - CONNECTING ROD BOLT
4 - FOUR DIGIT NUMBER
9a - 40 ENGINERG
PISTON & CONNECTING ROD (Continued)
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TURBOCHARGER SYSTEM
DESCRIPTION
CAUTION: The turbocharger is a performance part
and must not be tampered with. The wastegate
bracket is an integral part of the turbocharger. Tam-
pering with the wastegate components can reduce
durability by increasing cylinder pressure and ther-
mal loading due to incorrect inlet and exhaust man-
ifold pressure. Poor fuel economy and failure to
meet regulatory emissions laws may result. Increas-
ing the turbocharger boost WILL NOT increase
engine power.
The turbocharger is an exhaust-driven super-
charger which increases the pressure and density of
the air entering the engine. With the increase of air
entering the engine, more fuel can be injected into
the cylinders, which creates more power during com-
bustion.
The turbocharger assembly consists of four (4)
major component systems (Fig. 1) (Fig. 2):
²Turbine section
²Compressor section
²Bearing housing
²Wastegate
OPERATION
Exhaust gas pressure and energy drive the tur-
bine, which in turn drives a centrifugal compressor
that compresses the inlet air, and forces the air into
the engine through the charge air cooler and plumb-
ing. Since heat is a by-product of this compression,
the air must pass through a charge air cooler to cool
the incoming air and maintain power and efficiency.
Increasing air flow to the engine provides:
²Improved engine performance
²Lower exhaust smoke density
²Improved operating economy
²Altitude compensation
²Noise reduction.
The turbocharger also uses a wastegate (Fig. 3),
which regulates intake manifold air pressure and
prevents over boosting at high engine speeds. When
the wastegate valve is closed, all of the exhaust gases
flow through the turbine wheel. As the intake mani-
fold pressure increases, the wastegate actuator opens
the valve, diverting some of the exhaust gases away
from the turbine wheel. This limits turbine shaft
speed and air output from the impeller.
The turbocharger is lubricated by engine oil that is
pressurized, cooled, and filtered. The oil is delivered
to the turbocharger by a supply line that is tapped
into the oil filter head. The oil travels into the bear-
ing housing, where it lubricates the shaft and bear-
ings (Fig. 4). A return pipe at the bottom of the
Fig. 1 Turbocharger Operation
1 - TURBINE SECTION
2 - EXHAUST GAS
3 - BEARING HOUSING
4 - COMPRESSOR SECTION
5 - INLET AIR
6 - COMPRESSED AIR TO ENGINE
7 - EXHAUST GAS
8 - EXHAUST GAS TO EXHAUST PIPE
Fig. 2 Turbocharger Wastegate Actuator
1 - TURBOCHARGER
2 - DIAPHRAGM
3 - WASTE GATE ACTUATOR
11a - 2 EXHAUST SYSTEM AND TURBOCHARGERRG
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