2014 Flex Workshop Manual

SECTION 303-04C: Fuel Charging and Controls — Turbocharger, 3.5L GTDI	2014 Flex Workshop Manual
DIAGNOSIS AND TESTING	Procedure revision date: 05/02/2013

Turbocharger

Principles of Operation

The turbocharger is an exhaust-driven centrifugal air compressor. Its purpose is to increase power output by supplying compressed air to the engine. The internal components are oil, coolant and air cooled. Engine oil and coolant are circulated through the center housing which acts as a heat barrier between the "hot" turbine and the "cold" compressor. Bearings are sleeve type and lubricated by engine oil. Oil is circulated to the turbocharger center housing and returned to the sump through an oil drain in the center housing.

Expanding exhaust gases drive the turbine shaft assembly to speeds up to 200,000 rpm. Filtered air entering the compressor side of the turbocharger is compressed and delivered through a Charge Air Cooler (CAC). The very hot compressed air is cooled, then continues on to fill the intake manifold at a higher pressure than atmospheric pressure. Because considerably more air is forced into the intake manifold, the results are increased power, fuel efficiency and the ability to maintain power at higher altitudes.

Inspection and Verification

NOTE: This section provides mechanical diagnosis of the turbocharger assembly. If there is a Malfunction Indicator Lamp (MIL) illuminated, or DTCs are present, these should be diagnosed prior to performing turbocharger mechanical diagnosis. Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

Verify the customer concern.

Inspect the entire turbocharger system for obvious signs of damage or other mechanical concerns, using the following chart.

Visual Inspection Chart

Mechanical
Oil inlet pipe and connection Oil outlet pipe and connection Compressor housing inlet circuit and piping Compressor housing outlet circuit and piping Turbine housing inlet circuit and piping Turbine housing outlet circuit and piping Turbocharger actuator tubing or linkage

If the concern(s) remains after the inspection, GO to Symptom Chart .

If a driveability condition still exists, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

Symptom Chart

Symptom Chart
Condition	Possible Sources	Action
Loss of power/performance	Clogged Air Cleaner (ACL) element	INSTALL a new ACL element. REFER to Section 303-12 . TEST the system for normal operation.
	Loose connections or damage to air intake hoses and tubes	TIGHTEN the hose clamps. INSPECT for damage and REPAIR as necessary.
	Malfunctioning fuel system	REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
	Poor fuel quality	DRAIN and FILL with fresh fuel.
	Engine wear (piston rings, valve guides)	REPAIR as required.
	Turbocharger turbine or compressor wheel damage	INSPECT the turbocharger. REFER to the Check for Free Rotation — Off Vehicle in this section.
	Damaged exhaust or exhaust leaks at turbocharger housing or exhaust manifolds	INSPECT for leaks. Leaks can usually be detected audibly or visually, by a discoloration caused by escaping hot exhaust gases. REPAIR as required.
	Malfunctioning turbocharger bypass valve	REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
	Obstructed wastegate actuator linkage	INSPECT the suspect turbocharger wastegate linkage for obstruction. REPAIR as necessary.
	Damaged wastegate actuator linkage	INSPECT the suspect turbocharger wastegate linkage for damage. INSTALL a new turbocharger.
	Wastegate actuator operation	TEST the wastegate actuator operation. REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
	PCM — DTCs	REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
Excessive oil consumption	Incorrect type or grade of oil	DRAIN and FILL with specified oil.
	Oil in exhaust manifolds	REPAIR as required.
	Clogged ACL element	INSTALL a new ACL element. REFER to Section 303-12 . TEST the system for normal operation.
	Blocked or restricted turbocharger oil drain pipes	INSPECT the turbocharger oil drain pipes. REPAIR as necessary.
	Damaged or collapsed air intake hoses and tubes	TIGHTEN hose clamps. INSPECT for damage and REPAIR as necessary.
	Damaged exhaust or exhaust leaks at turbocharger housing or exhaust manifolds	INSPECT for leaks. Leaks can usually be detected audibly or visually, by a discoloration caused by escaping hot exhaust gases. REPAIR as required.
	Turbocharger oil seals leaking	REFER to Turbocharger Internal Oil Leak Test in this section.
	Damaged crankcase ventilation system	Visually INSPECT the crankcase ventilation system.
Excessive noise	Turbocharger compressor air intake pipe leaking	REPAIR or INSTALL a new pipe as required.
	Loose connections or damage to air intake hoses and tubes	TIGHTEN hose clamps. INSPECT for damage and REPAIR as necessary.
	Air leaks at turbine housing, blown joints or damaged exhaust	INSPECT for leaks. Leaks can usually be detected audibly or visually, by a discoloration caused by escaping hot exhaust gases. REPAIR as required.
	Carbon build up in the turbine housing causing contact with turbine wheel	INSPECT the turbocharger. REFER to the Check for Free Rotation — Off Vehicle in this section.
	Turbocharger imbalance due to foreign object/damage	REPAIR as required.
	Turbine bearing failure	INSPECT the turbocharger. REFER to the Check for Free Rotation — Off Vehicle in this section.
	Inoperative turbocharger bypass valve	REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
Engine emits excessive smoke (black/blue/white)	Clogged ACL element	INSTALL a new ACL element. REFER to Section 303-12 . TEST the system for normal operation.
	Incorrect type or grade of oil	DRAIN and FILL with specified oil.
	Blocked or restricted turbocharger oil drain pipes	INSPECT the turbocharger oil drain pipes. REPAIR as necessary.
	Damaged/restricted or leaking turbocharger compressor air intake pipe	REPAIR or INSTALL a new pipe as required.
	Engine wear (piston rings, valve guides)	REPAIR as required.
	Plugged crankcase ventilation system	Visually INSPECT the crankcase ventilation system.
	Turbocharger oil seals leaking	REFER to Turbocharger Internal Oil Leak Test in this section.

Component Tests

Turbocharger Internal Oil Leak Test

NOTE: Some engine oil may be present in the turbocharger compressor inlet and in the air inlet components due to the crankcase breather system.

Check the turbocharger compressor inlet for evidence of oil. If excessive oil is present, this indicates that the failure could be in the engine or turbocharger. Refer to Section 303-00 or the following turbocharger check. If excessive oil is found in the turbocharger compressor outlet, check the Charge Air Cooler (CAC) for oil contamination. If contamination is present, flush the CAC . Refer to Section 303-12 .

Check the turbocharger turbine outlet for evidence of oil. If excess oil is present in the outlet, remove the turbocharger from the engine and examine the oil supply and return passages in the turbocharger and engine block for restriction. If no restriction is found, install a new turbocharger.

Check for Free Rotation — Off Vehicle

NOTE: The turbocharger must be pre-oiled before carrying out this check.

NOTE: Turbine and compressor wheels must spin freely when turned by hand. No housing contact is permitted.

Inspect the turbocharger compressor and turbine fins for damage. If the compressor or turbine wheel fins are damaged, replace the turbocharger.

Press and rotate the turbocharger shaft, then repeat from the opposite side. If either the compressor wheel or the turbine wheel contacts the housing, the bearings are bad and a new turbocharger must be installed.