Symptom Chart

Symptom	Possible Sources	Action
Loss of power/performance	Clogged Air Cleaner (ACL) element	INSTALL a new Air Cleaner (ACL) element. TEST the system for normal operation.
Loose connections or damage to air intake hoses and tubes		INSPECT for damage. TIGHTEN the hose clamps. REPAIR as needed.
Malfunctioning fuel system		Refer to ENGINE CONTROLS - SYMPTOM CHARTS (EXCEPT DIESEL & HYBRID) .
Poor fuel quality		DRAIN and FILL with fresh fuel.
Engine wear (piston rings, valve guides)		REPAIR as needed.
Turbocharger turbine or compressor wheel damage		INSPECT the turbocharger. REFER to CHECK FOR FREE ROTATION - Off Vehicle .
Damaged exhaust or exhaust leaks at turbocharger housing		INSPECT for leaks. Leaks can usually be detected audibly or visually, by a discoloration caused by escaping hot exhaust gases. REPAIR as needed.
Malfunctioning turbocharger bypass valve		Refer to ENGINE CONTROLS - SYMPTOM CHARTS (EXCEPT DIESEL & HYBRID) .
Obstructed wastegate actuator linkage		INSPECT the turbocharger wastegate linkage for obstructions. REPAIR as needed.
Damaged wastegate actuator linkage		INSPECT the turbocharger wastegate linkage for damage. INSTALL a new turbocharger as needed. REFER to: Turbocharger .
Wastegate actuator operation		TEST the wastegate actuator operation. Refer to ENGINE CONTROLS - SYMPTOM CHARTS (EXCEPT DIESEL & HYBRID) .
PCM (powertrain control module) - DTC (diagnostic trouble code)		REFER to: Electronic Engine Controls .

Symptom	Possible Sources	Action
Excessive oil consumption	Incorrect type or grade of oil	DRAIN and FILL with specified oil.
Oil in the cylinder head to turbocharger flange		REPAIR as needed.
Clogged Air Cleaner (ACL) element		INSTALL a new Air Cleaner (ACL) element. TEST the system for normal operation.
Blocked or restricted turbocharger oil drain tube		INSPECT the turbocharger oil drain tube. REPAIR as needed.
Damaged or collapsed air intake hoses and tubes		INSPECT for damage. TIGHTEN the hose clamps. REPAIR as needed.
Damaged exhaust or exhaust leaks at turbocharger housing to cylinder head		INSPECT for leaks. Leaks can usually be detected audibly or visually, by a discoloration caused by escaping hot exhaust gases. REPAIR as needed.
Turbocharger oil seals leaking		REFER to Turbocharger Internal Oil Leak Test .
Damaged crankcase ventilation system		Visually INSPECT the crankcase ventilation system. REPAIR as needed.

Symptom	Possible Sources	Action
Excessive noise	Turbocharger compressor air intake pipe leaking	INSPECT for damage. TIGHTEN the hose clamps. REPAIR as needed.
Loose connections or damage to air intake hoses and tubes		INSPECT for damage. TIGHTEN the hose clamps. REPAIR as needed.
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 needed.
Carbon build up in the turbine housing causing contact with turbine wheel		INSPECT the turbocharger. REFER to CHECK FOR FREE ROTATION - Off Vehicle .
Turbocharger imbalance due to foreign object/damage		REPAIR as needed.
Turbine bearing failure		INSPECT the turbocharger. REFER to CHECK FOR FREE ROTATION - Off Vehicle .
Inoperative turbocharger bypass valve		Refer to ENGINE CONTROLS - SYMPTOM CHARTS (EXCEPT DIESEL & HYBRID) .

Symptom	Possible Sources	Action
Engine emits excessive smoke (black/blue/white)	Clogged Air Cleaner (ACL) element	INSTALL a new Air Cleaner (ACL) element. TEST the system for normal operation.
Incorrect type or grade of oil		DRAIN and FILL with specified oil.
Blocked or restricted turbocharger oil drain tube		INSPECT the turbocharger oil drain tube. REPAIR as needed.
Damaged/restricted or leaking turbocharger compressor air intake pipe		INSPECT for damage. TIGHTEN the hose clamps. REPAIR as needed.
Engine wear (piston rings, valve guides)		REPAIR as needed.
Plugged crankcase ventilation system		Visually INSPECT the crankcase ventilation system. REPAIR as needed.
Turbocharger oil seals leaking		REFER to Turbocharger Internal Oil Leak Test .

Symptom	Possible Sources	Action
Turbocharger oil leaks	Turbocharger oil tube seals and/or oil tube leaking	Visually INSPECT the turbocharger oil tubes and the turbocharger oil tube seals/gaskets. REPLACE the turbocharger oil tube seals/gaskets and the turbocharger oil tubes as needed. REFER to: Turbocharger Oil Return Tube . REFER to: Turbocharger Oil Supply Tube .

Symptom	Possible Sources	Action
Turbocharger coolant leaks	Turbocharger coolant tube seals and/or coolant tube leaking	Visually INSPECT the turbocharger coolant tubes and the turbocharger coolant tube seals/gaskets. REPLACE the turbocharger coolant tube seals/gaskets and the turbocharger coolant tubes as needed. REFER to: Turbocharger Coolant Return Tube . REFER to: Turbocharger Coolant Supply Tube .