Turbocharger Dodge Dakota Shelby

DESCRIPTION

The turbocharger assembly houses a vacuum operated actuator, wastegate assembly and center housing rotating assembly for the compressor and turbine wheels. In addition to the turbocharger assembly, the system includes a Single Module Engine Controller (SMEC) controlled wastegate solenoid and a network of hoses to process the necessary coolant, oil and air supply.

COMPRESSOR

Exhaust gas is directed into the turbocharger past the turbine wheel blades where it is used to drive the center housing rotating assembly. The compressor wheel, like the turbine wheel, is attached to the center housing rotating assembly shaft. Compressor wheel rotation draws air into the compressor chamber through the air inlet duct. The air is then forced into the throttle body and pressurizes the air/fuel mixture into the intake manifold. To control the high pressure created by the turbocharger, the wastegate (pressure relief valve) will activate at a pre-determined value to prevent "over boost".

Scheme 6

TURBINE ASSEMBLY

The turbine is connected to the compressor by a shaft. The exhaust gas passes across the turbine wheel blades forcing the turbine wheel to rotate. Increased exhaust gas volume and pressure causes an increase in turbine speed. Faster rotation of the turbine increases compressor output. The turbine shaft is lubricated by oil from the engine.

WASTEGATE & ACTUATOR

The wastegate limits intake manifold pressure to a pre-set maximum. The actuator is a pressure-sensitive diaphragm. Operation of the wastegate is controlled by the wastegate solenoid and the SMEC. As maximum boost pressure is obtained, the actuator causes the wastegate to open. At this point, a portion of the exhaust gas is diverted around the turbine and enters the header pipe directly. The wastegate is mounted to the turbine assembly. (Scheme 6)

WASTEGATE SOLENOID

The wastegate solenoid receives electrical signals from the SMEC that regulate the duty cycle of the solenoid. The on/off action of the solenoid determines the amount of turbocharger boost by regulating vacuum signals applied to the actuator. (Scheme 7)and (Scheme 8).

Scheme 7

OIL SUPPLY

Turbochargers must have constant flow of clean engine oil for proper operation. Oil is supplied directly into the center housing of turbocharger. Oil feed pipe runs from fitting on the engine block to the turbocharger center housing. Engine oil is returned into the engine block by a tube attached to housing of turbocharger. Change oil and filter. Flush turbocharger with clean oil ANYTIME there is oil contamination.

* PLEASE READ THIS FIRST *

Note. Each turbocharger has a unique noise level when operating. If the sound cycles up and down, check for air restrictions in the intake tube and for dirt build-up in the compressor housing or wheel. If a high-pitched noise or whistle occurs, check for inlet air or exhaust gas leak.

FAULT CODES

Fault codes associated with the turbocharging system are code 36, open or short circuit in the wastegate solenoid, and code 45, boost limit exceeded. For more information on fault codes and code descriptions, see COMPUTER CONTROLS section.

WASTEGATE ACTUATOR ASSEMBLY

1. Remove hose from wastegate actuator assembly. Connect cooling system pressure tester to wastegate diaphragm. Slowly apply pressure while observing wastegate actuator rod.
2. If actuator rod does not move at about 5 psi (.35 kg/cm 2 ), wastegate is defective. Replace turbocharger assembly and repeat test procedure.

Scheme 8

1. Remove exhaust outlet pipe from turbocharger housing. Using a mirror, observe movement of the wastegate while operating the actuator linkage manually.
2. If wastegate fails to open or close, replace turbocharger assembly. Spin the compressor wheel and check for binding. Replace turbocharger if binding exists.
3. Remove the oil drain back from the center housing. Check center housing for sludge in the oil drain area. If heavily sludged or caked, replace turbocharger assembly.
4. Inspect compressor wheel and housing for signs of oil leakage, gouges, nicks, or distortion. If damaged or oil leakage, replace turbocharger assembly.

Note. Change engine oil and filter when replacing turbocharger.

REMOVAL PRECAUTIONS

Prior to any unit repair on a turbocharging system, several general precautions should be considered.

1. Clean area around turbocharger with non-caustic solution before disassembly.
2. Use extreme care during removal to avoid damage to turbine blades. Any damage may result in turbocharger failure when engine is started.
3. Scribe reference marks on turbine and compressor housing before disassembly to ensure correct assembly alignment.
4. If any joints are found to be coated with sealer, clean thoroughly and recoat with sealant during assembly.

Note. Turbocharger is removed from beneath vehicle.

Removal

1. Disconnect negative battery cable. Drain cooling system. Remove air cleaner hoses and air cleaner assembly. Remove front engine through bolt and tilt engine towards front of vehicle.
2. Disconnect and remove coolant hose from water box. (Scheme 6) Disconnect oil feed line at turbocharger. Remove wastegate rod retaining clip. Remove 3 (leaving one lower nut) turbocharger-to-exhaust manifold nuts. Disconnect oxygen sensor electrical connector. Disconnect necessary vacuum hoses.
3. Remove right front drive axle spindle nut. Raise and support vehicle. Remove speedometer pinion assembly from transaxle. Tap axle shaft end lightly with brass hammer to free axle shaft from hub splines. Remove right lower ball joint clamp bolt. Separate lower ball joint from steering knuckle.
4. Pull out on hub/steering knuckle assembly and separate right axle shaft from hub. Grasp both CV joints halves, to prevent separation, and pull axle shaft out of transaxle or intermediate shaft. Remove axle shaft from vehicle.
5. Remove turbocharger-to-block support bracket. Disconnect and remove oil drain tube from turbocharger. Remove one remaining turbocharger-to-exhaust manifold nut. Disconnect exhaust pipe joint from turbocharger housing.
6. Remove lower coolant line and fitting at turbocharger. Lift turbocharger off exhaust manifold studs and lower assembly down and out of vehicle.

Scheme 9

Note. When replacing turbocharger, pour fresh engine oil into oil feed line fitting on turbocharger before installing oil feed line.

Installation

To install, reverse removal procedures. Ensure turbocharger tightening specifications are followed. Apply anti-seize compound to exhaust manifold studs. Ensure turbine wheel turns freely before installing exhaust pipe.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS