Symptom Chart

Symptom	Possible Sources	Action
Loss of power/performance	Clogged air cleaner element	INSTALL a new air cleaner element. TEST the system for normal operation.
	Loose connections or damage to air intake pipes	INSPECT for damage. REPAIR as needed. TIGHTEN the hose clamps.
	Malfunctioning fuel system	Refer to Engine Controls - Description & Operation (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 the Check for Free Rotation -- On 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 - Description & Operation (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.
	Wastegate actuator operation	TEST the wastegate actuator operation. Refer to Engine Controls - Description & Operation (Except Diesel & Hybrid)
	PCM -- DTC	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 exhaust manifolds	REPAIR as needed.
	Clogged air cleaner elements	INSTALL a new air cleaner element. TEST the system for normal operation.
	Blocked or restricted turbocharger oil drain tubes	INSPECT the turbocharger oil drain tube. REPAIR as needed.
	Damaged or collapsed air intake pipes	INSPECT for damage. REPAIR as needed. TIGHTEN the hose clamps.
	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 intake pipes leaking	REPAIR or INSTALL a new pipe as needed.
	Loose connections or damage to air intake pipes	INSPECT for damage. REPAIR as needed. TIGHTEN the hose clamps.
	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 the Check for Free Rotation -- On Vehicle .
	Turbocharger imbalance due to foreign object/damage	REPAIR as needed.
	Inoperative turbocharger bypass valve	Refer to Engine Controls - Description & Operation (Except Diesel & Hybrid)

Symptom	Possible Sources	Action
Engine emits excessive smoke (black/blue/white)	Clogged air cleaner elements	INSTALL a new air cleaner 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 tubes	INSPECT the turbocharger oil drain tube. REPAIR as needed.
	Damaged/restricted or leaking turbocharger intake pipes	REPAIR or INSTALL a new pipe 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
External oil leaks or oil tube 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.

Symptom	Possible Sources	Action
External coolant leaks or coolant tube 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.