Normal Operation and Fault Conditions
Since it is possible that any one of multiple
systems may be the cause of the symptom, it may be necessary to use a
process of elimination type of diagnostic approach to pinpoint the
responsible system. NVH
symptoms should be identified using the diagnostic tools and
techniques that are available. For a list of these techniques, tools, an
explanation of their uses and a glossary of common terms, REFER to:
Noise, Vibration and Harshness (NVH) (100-04 Noise, Vibration and
Harshness, Diagnosis and Testing).
In some cases, a noise may be a normal
characteristic of that engine type. In other cases the noise may require
further investigation. Comparing the noise to a similar year/model
vehicle equipped with the same engine aids in determining if the noise
is normal or abnormal.
Once a concern is identified as an abnormal
engine noise, it is critical to determine the location of the specific
noise. Use the EngineEAR/ChassisEAR or stethoscope (the noise is always
louder closer to the noise source) to isolate the location of the noise
to one of the following areas.
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Fuel injector(s)
-
Upper end of engine
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Lower end of engine
-
Front of engine
-
Rear of engine
Fuel injector noise
A common source of an engine ticking noise can be
related to the fuel injection pump (Ecoboost engine) or fuel
injector(s). This is normal engine noise that can be verified by
listening to another like vehicle. If the injector noise is excessive or
irregular, use the EngineEAR/ChassisEAR or stethoscope to isolate the
noise to a specific fuel injector.
Upper End Engine Noise
A common source of upper end engine noise
(ticking, knocking or rattle) includes the camshaft(s) and valve train.
Upper end engine noise can be determined using the EngineEAR/ChassisEAR
or stethoscope on the valve cover bolts. If the noise is loudest from
the valve cover bolts, the noise is within the upper end. The
EngineEAR/ChassisEAR or stethoscope can be used to further isolate the
noise to the specific cylinder bank and cylinder. Removal of the valve
covers is required to pinpoint the source of the noise.
Lower End Engine Noise
A common source of lower end engine noise
(ticking or knocking) includes the crankshaft, connecting rod(s) and
bearings. Lower end noises can be determined by using the engine oil pan
or lower cylinder block. If the noise is loudest from these areas, the
noise is within the lower end. If an engine noise is isolated to the
lower end, some disassembly of the engine may be required to inspect for
damage or wear.
Front of Engine Noise
A common source of noise from the front of the engine (squeal,
chirp, whine or hoot) is the FEAD components. To isolate FEAD noise,
carry out the Engine Accessory Test, REFER to: Noise, Vibration and
Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and
Testing).
Some other noises from the front of the engine
(ticking, tapping or rattle) may be internal to the engine. Use the
EngineEAR/ChassisEAR or stethoscope on the engine front cover to
determine if the noise is internal to the engine. Removal of the engine
front cover may be necessary to inspect internal engine components.
Rear of Engine Noise
A common source of noise from the rear of the
engine (knocking) is the flywheel/flexplate. Inspection of the
flywheel/flexplate is necessary.
Some engines have timing drive components at the
rear of the engine and may be the source of noise (ticking, knocking or
rattle). Use the EngineEAR/ChassisEAR or stethoscope on the rear of the
engine if the noise is suspected to be internal to the engine. Some
disassembly of the engine may be required to inspect for damage or wear.
Turbocharger Noise (Ecoboost Engine)
A common source of noise is the turbocharger. Some whine or air rush noise is an acceptable condition.
To help locate the source of engine noise, REFER to: Engine Noise
Identification and Location (303-00 Engine System - General Information,
General Procedures).
Possible Sources
- Expanding/contracting materials
- Thin or diluted engine oil
- Low engine oil level
- Vacuum leak
- Cooling system concern
- Powertrain mount(s)
- Drivetrain
- Accessory drive system concern
- Air intake system concern
- Turbocharger bypass valve
- Turbocharger
- Engine or transmission interference to chassis or body
- Starter motor
- Fuel injector
- Fuel pump
- Fuel injection pump (direct injection engines only)
- Flywheel/flexplate
- Timing drive system concern
- Valve train component concern
- Cylinder head
- Balance shaft assembly
- Engine oil pump
- Lower end rotating assembly (connecting rods or crankshaft) concern
- Pistons/cylinder walls
NOTE:
A metal pinging/clicking sound occurring while the
engine is cooling down after reaching normal operating temperature is
considered normal.
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F1 COMPARE TO A LIKE VEHICLE |
-
Compare the noise concern to a like vehicle, similarly equipped.
Is the noise of concern present in the like vehicle?
Yes |
The vehicle is operating as designed.
|
|
F2 CHECK FOR OBVIOUS SIGNS OF MECHANICAL DAMAGE |
-
Visually inspect the powertrain components and all
possible causes listed for obvious signs of mechanical damage.
Is any mechanical damage present?
|
F3 CHECK THE ENGINE OIL LEVEL |
-
Check the engine oil level.
Is the engine oil level OK?
No |
FILL the engine oil to specification.
|
|
F4 CHECK THE ENGINE OIL FOR CONTAMINATION |
-
Check the engine oil for contamination.
Is the engine oil free of contamination?
No |
IDENTIFY the source of the contamination and REPAIR as necessary.
|
|
F5 CHECK THE VEHICLE SERVICE HISTORY |
-
Check the vehicle service history and make sure the correct engine oil used is documented.
Is the correct engine oil used based on the vehicle service history?
No |
CHANGE the engine oil and filter using the correct
engine oil specification. Refer to the Specifications procedure in the
303-01 section for the engine being diagnosed. Refer to the appropriate
section in Group 303 for the procedure.
|
|
F6 CHECK FOR PCM (POWERTRAIN CONTROL MODULE)
DIAGNOSTIC TROUBLE CODES (DTCS) |
-
Carry out the PCM
KOEO and KOER self-tests.
Are any Diagnostic Trouble Codes (DTCs) present?
Yes |
REFER to the Master DTC Chart to diagnose the DTC present.
|
|
F7 CHECK FOR AN ENGINE OVERHEATING CONCERN |
-
Check the engine for an overheating condition.
Is an engine overheat condition present?
Yes |
REFER to the Diagnosis and Testing procedure in the
303-03 section for the engine being diagnosed. Refer to the appropriate
section in Group 303 for the procedure.
|
|
F8 CHECK THE COOLANT PUMP END PLAY |
-
Check the coolant pump for excessive end play.
Inspect the coolant pump for imbalance with the drive belt off.
Is any concern with the coolant pump present?
|
F9 CHECK FOR A VACUUM LEAK |
NOTE:
A smoke machine may be used to identify the location of a vacuum leak.
-
Inspect the vacuum hoses for leaks and check the engine for a vacuum leak.
Is a vacuum leak present?
|
F10 CHECK THE AIR INTAKE SYSTEM |
NOTE:
The turbocharger bypass valve closes approximately
30 seconds after cold start up creating a pop noise. This is a normal
operating condition.
NOTE:
A hissing noise on vehicles with a plastic intake
manifold may occur during idle or high idle that is apparent with the
hood open. This is a normal operating condition.
-
Inspect the air intake system.
-
Check the air intake ducts, air cleaner and throttle body for leaks and correct fit.
-
If equipped, check the turbocharger/supercharger and CAC and tubes for leaks, correct alignment and damage.
Is any concern discovered with the air intake system?
Yes |
REPAIR or adjust as necessary.
|
|
F11 CHECK THE IGNITION SYSTEM |
-
Inspect the ignition system. Inspect the spark plugs for normal burning.
REFER to: Spark Plug Inspection (303-00 Engine System - General Information, General Procedures).
Is any concern found with the ignition system?
|
F12 CHECK THE ACCESSORY DRIVE SYSTEM |
NOTE:
The Engine Cold Soak and Engine Accessory Test
procedures can be used to help identify a concern with the accessory
drive. If a concern exists, place the EngineEAR probe directly on the
idler/tensioner center post or bolt to verify which bearing is making
the noise.
-
Inspect the accessory drive system.
-
If necessary, carry out the Engine Accessory Test.
REFER to: Noise, Vibration and Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing).
Is any concern discovered with the accessory drive system?
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F13 CHECK THE FUEL SYSTEM |
NOTE:
The fuel pump module turns on before the engine
starts to prime the fuel system. A whine or hum may be heard when
unlocking the vehicle or opening the door with the engine off. This is a
normal operating condition.
-
Inspect the fuel injection system. REFER to the
Diagnosis and Testing procedures in the 303-04 and 310-01 section for
the engine being diagnosed. Refer to the appropriate section in Group
303 for the procedure.
Is any concern discovered with the fuel injection system?
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F14 CHECK THE STARTER MOTOR |
-
Inspect the starter motor for damage and correct
installation. REFER to the Diagnosis and Testing procedure in the 303-06
section for the engine being diagnosed. Refer to the appropriate
section in Group 303 for the procedure.
Is any concern discovered with the starter motor?
|
F15 CHECK THE POWERTRAIN MOUNTS |
-
Inspect the powertrain mounts for damage.
Is any concern discovered with the powertrain mounts?
Yes |
PERFORM the Powertrain/Drivetrain Mount Neutralizing procedure. REFER to: Powertrain/Drivetrain Mount Neutralizing (303-00 Engine System - General Information, General Procedures). . If the concern still exists, REPAIR or INSTALL new powertrain mounts as necessary.
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F16 CHECK THE EXHAUST SYSTEM |
-
Inspect the exhaust system for damage. REFER to the
Diagnosis and Testing procedure in the 309-00 section for the engine
being diagnosed. Refer to the appropriate section in Group 303 for the
procedure.
Is exhaust system the cause of the noise?
Yes |
REPAIR or INSTALL new components as necessary.
|
|
F17 CHECK FOR TURBOCHARGER NOISE |
-
Check the turbocharger(s) for excessive noise.
Compare the noise to another vehicle similarly equipped. REFER to the
303-04 turbocharger Diagnosis and Testing procedure for the engine being
diagnosed. Refer to the appropriate section in Group 303 for the
procedure.
Are the turbocharger(s) the cause of the noise?
Yes |
INSTALL new turbocharger(s).
|
|
F18 CHECK ENGINE OIL PRESSURE |
-
Check the engine oil pressure.
REFER to: Oil Pressure Test (303-00 Engine System - General Information, General Procedures).
Compare the engine oil pressure gauge to the engine oil pressure
specifications in the 303-01 specifications procedure of the engine
being diagnosed. Refer to the appropriate section in Group 303 for the
procedure.
Is the engine oil pressure within specification?
|
F19 IDENTIFY THE LOCATION OF THE ENGINE NOISE |
-
Using EngineEAR/ChassisEAR, stethoscope and accelerometers along with the VCMM , locate the engine noise.
REFER to: Engine Noise Identification and Location (303-00 Engine System - General Information, General Procedures).
Is the noise coming from the engine?
Yes |
If the noise is coming from the rear of the engine GO to F20 If the
noise is coming from the front of the engine, GO to F21 If the noise is
coming from the upper end of the engine, GO to F22 If the noise is
coming from the lower end of the engine, GO to F25
|
No |
The condition is not present at this time.
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F20 CHECK THE FLEXPLATE OR FLYWHEEL AND CLUTCH |
-
If equipped, remove the torque converter nut/bolt
access plug. If equipped, remove the inspection cover. If needed, remove
the starter motor. Check if the torque converter nuts or bolts are
loose. Visually inspect the flexplate or flywheel and clutch for damage.
Using an assistant, rotate the crankshaft pulley by hand while
inspecting the flexplate or flywheel and clutch and listening for
unusual noises coming from between the engine and transmission. Check to
be sure the flexplate or flywheel do not feel loose on the crankshaft.
Restrict the movement of the flexplate or flywheel while an assistant
turns the crankshaft by hand if needed to help identify a possible
source of the noise.
Is damage found to the flexplate, flywheel or
clutch, are the torque converter, flexplate or flywheel fasteners loose
or does the noise seem to be coming from between the engine and
transmission?
Yes |
REMOVE the transmission. INSPECT the flexplate or
flywheel and clutch for damage. INSTALL a new flexplate or flywheel and
clutch as needed.
|
|
F21 CHECK THE TIMING DRIVE COMPONENTS |
-
Remove the engine front cover. Inspect the timing
components for excessive wear or damage. Inspect the engine front cover
for contact marks from the timing chain or belt. Inspect the VCT unit(s) for damage or excessive wear.
Is damage found to the timing drive components?
Yes |
INSTALL new timing drive components.
|
|
F22 CHECK THE VALVE TRAIN FOR DAMAGE |
-
Remove the valve cover(s). Visually inspect the
camshafts and valve train for obvious signs of excessive wear or damage.
Check for broken valve springs, damaged valve retainers, missing or
damaged valve keepers or bent valves.
Is damage found to the valve train?
Yes |
INSTALL new components.
|
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F23 PERFORM VALVE TRAIN ANALYSIS |
-
Perform the valve train analysis.
REFER to: Valve Train Analysis -
2.0L EcoBoost (177kW/240PS) – MI4/2.5L Duratec – Hybrid (121kW/164PS)
(BG) (303-00 Engine System - General Information, General Procedures). .
Compare the camshaft lift to the specifications in the 303-01 section
for the engine being diagnosed. Refer to the appropriate section in
Group 303 for the procedure.
Is the camshaft lift and valve clearance within specifications?
No |
ADJUST the valve clearance. If necessary, INSTALL new camshafts, camshaft roller followers or valve tappets.
|
|
F24 CHECK THE CYLINDER HEAD AND VALVES |
-
Remove the cylinder head(s). Remove the valves from
the cylinder heads and inspect the valves and valve guides for excessive
wear or damage.
REFER to: Valve Stem Diameter (303-00 Engine System - General Information, General Procedures).
REFER to: Valve Guide Inner Diameter (303-00 Engine System - General Information, General Procedures).
Compare the measurement to the valve stem-to-guide clearance
specification in 303-01 specifications for the engine being diagnosed.
Refer to the appropriate section in Group 303 for the procedure.
Are the valve clearances within specifications?
No |
INSTALL new cylinder head(s) and valves.
|
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F25 CHECK THE BALANCE SHAFTS FOR DAMAGE OR EXCESSIVE WEAR |
-
If equipped, remove the balance shaft assembly.
Inspect the balance shaft assembly for excessive wear or damage. Check
the bearing surfaces for excessive wear or damage.
Is damage or excessive wear found on the balance shaft assembly or the bearings?
Yes |
If debris from the balance shaft or bearings appear to have entered the
engine oil, GO to F26INSTALL a new balance shaft assembly.
|
|
F26 CHECK THE ENGINE OIL PUMP |
-
Remove the engine oil pump. Check the engine oil
pump for damage or excessive wear. Check for cracks on the housing.
Check for scoring or excessive clearance on the gearotor or internal
moving parts.
Is the engine oil pump damaged?
Yes |
If debris from the balance shaft or bearings appear to have entered the engine oil, GO to F27 INSTALL a new engine oil pump.
|
|
F27 CHECK THE CONNECTING ROD BEARINGS |
-
Remove the engine oil pan. Remove the connecting rod
caps and check the bearings for signs of excessive wear or damage.
Check the connecting rod bearing journal clearance.
REFER to: Connecting Rod Bearing Journal Clearance (303-00 Engine System - General Information, General Procedures).
Compare the connecting rod bearing journal clearance to the connecting
rod bearing journal clearance specification in the specifications
procedure for the 303-01 section of the engine being diagnosed. Refer to
the appropriate section in Group 303 for the procedure.
Are the connecting rod bearing journal clearances within specifications?
No |
If debris from the failed bearings or crankshaft appear to have entered
the engine oil, GO to F28. INSTALL new connecting rod bearings.
|
|
F28 CHECK THE CRANKSHAFT MAIN BEARINGS |
-
Remove the crankshaft main bearing caps and check
the bearings for signs of excessive wear or damage. Check the crankshaft
main bearing clearance.
REFER to: Crankshaft Main Bearing Journal Clearance (303-00 Engine System - General Information, General Procedures).
Compare the crankshaft main bearing journal clearance to the crankshaft
main bearing journal clearance specification in the specifications
procedure for the 303-01 section of the engine being diagnosed. Refer to
the appropriate section in Group 303 for the procedure.
Are the crankshaft main bearing journal clearances within specifications?
No |
INSTALL a new long block.
|
|
F29 CHECK THE PISTON TO CYLINDER WALL CLEARANCE |
-
Remove the engine. Remove the piston and connecting
rod assemblies from the engine. Inspect the pistons, piston rings and
cylinder walls for signs of piston slap. Inspect the pistons.
REFER to: Piston Inspection (303-00 Engine System - General Information, General Procedures). Check the piston ring end gap. REFER to: Piston Ring End Gap (303-00 Engine System - General Information, General Procedures).
Measure the cylinder bore taper. REFER to: Cylinder Bore Taper (303-00
Engine System - General Information, General Procedures). . Measure the piston diameter. REFER to: Piston Diameter (303-00 Engine System - General Information, General Procedures).
Calculate the piston-to-cylinder bore clearance and compare the
specification to the specification procedure in the 303-01 section for
the engine being diagnosed. Refer to the appropriate section in Group
303 for the procedure.
Is the piston-to-cylinder wall clearance within specification?
Yes |
INSTALL new piston rings. Hone the cylinder walls.
|
No |
INSTALL a new short block.
|
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