Symptom Chart - Engine NVH

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Engine NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, refer to NOISE, VIBRATION & HARSHNESS . 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. If this is not the causal system for the symptom, refer back to NOISE, VIBRATION & HARSHNESS for the next likely system and continue diagnosis.

SYMPTOM CHART - ENGINE NVH

Condition	Possible Sources	Action
Drone type noise	Powertrain mount(s)	CARRY OUT the POWERTRAIN/DRIVETRAIN MOUNT NEUTRALIZING procedure. TEST the system for normal operation.
Drumming noise - occurs inside the vehicle during idle or high idle, hot or cold. Very low-frequency drumming is very RPM dependent	Engine vibration excites the body resonances inducing interior noise	CARRY OUT the POWERTRAIN/DRIVETRAIN MOUNT NEUTRALIZING procedure. TEST the system for normal operation.
Engine drumming noise - accompanied by vibration	Powertrain mount(s)	CARRY OUT the POWERTRAIN/DRIVETRAIN MOUNT NEUTRALIZING procedure. TEST the system for normal operation.
Rattle - occurs at idle or at light acceleration from a stop	Powertrain mount(s)	CHECK the powertrain mounts for damage. For engine, REFER to ENGINE SUPPORT INSULATORS . For automatic transmission, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - TORQSHIFT 6 . REPAIR as necessary. TEST the system for normal operation.
	Damaged flexplate	INSPECT the flexplate. REFER to FLEXPLATE INSPECTION . REPAIR as necessary. TEST the system for normal operation.
	Fuel injector stuck open	REPLACE the fuel injector(s). REFER to FUEL CHARGING AND CONTROLS - 6.7L DIESEL . REPAIR as necessary. TEST the system for normal operation.
Whine/moan type noise - pitch increases or changes with vehicle speed	Powertrain mount(s)	CHECK the powertrain mounts for damage. For engine, REFER to ENGINE SUPPORT INSULATORS . For automatic transmission, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - TORQSHIFT 6 . REPAIR as necessary. TEST the system for normal operation.
	Valvetrain/Timing drive component noise	CARRY OUT the VALVE TRAIN ANALYSIS . REPAIR as necessary. TEST the system for normal operation
Clunk - occurs when shifting from PARK or between REVERSE and DRIVE	Powertrain mounts	CHECK the powertrain/drivetrain mounts for damage. For engine, REFER to ENGINE SUPPORT INSULATORS . For automatic transmission, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - TORQSHIFT 6 . REPAIR as necessary. TEST the system for normal operation.
	Driveshaft universal joint	INSPECT the driveshaft universal joints. REFER to DRIVESHAFT . REPAIR as necessary. TEST the system for normal operation.
Accessory drive bearing hoot - occurs at idle or high idle in cold temperatures of approximately +4°C (+40°F) or colder at the first start of the day	Accessory drive idler or tensioner pulley bearing is experiencing stick/slip between ball bearings and the bearing race	CARRY OUT the engine cold soak procedure. REFER to NOISE, VIBRATION & HARSHNESS . PLACE the EngineEAR probe directly on the idler/tensioner center post or bolt to verify which bearing is making the noise. REFER to ACCESSORY DRIVE . REPAIR as necessary. TEST the system for normal operation.
Accessory drive belt noise, squeal or chirping	Defective/worn or incorrect accessory drive belt Misaligned pulley(s) Pulley runout Damaged or worn accessory drive component or idler Fluid contamination of the accessory drive belt or pulleys Damaged or worn accessory drive belt tensioner Damaged pulley grooves	CARRY OUT the Engine Accessory Test. REFER to NOISE, VIBRATION & HARSHNESS . REFER to ACCESSORY DRIVE . REPAIR as necessary. TEST the system for normal operation.
Clunking noise	Coolant pump has excessive end play or imbalance	CHECK the coolant pump for excessive end play. REFER to ENGINE COOLING - DIESEL ENGINES . INSPECT the coolant pump for imbalance with the drive belt off. REPAIR as necessary. TEST the system for normal operation.
Whine or moaning noise	Air intake system Boost leak	CHECK the Air Cleaner (ACL) and ducts for correct fit. INSPECT the air intake system for leaks or damage. REFER to INTAKE AIR DISTRIBUTION & FILTERING . REPAIR as necessary. TEST the system for normal operation.
Whine or moaning noise	Excessive turbocharger noise	REMOVE and INSPECT the turbocharger. REFER to FUEL CHARGING AND CONTROLS - TURBOCHARGER . REPAIR as necessary. TEST the system for normal operation.
Whistling noise	Turbocharger inlet pipes	Inspect the turbocharger inlet pipes. REFER to EXHAUST SYSTEM . REPAIR as necessary. TEST the system for normal operation.
Whistling noise	EGR cooler pipes	INSPECT the EGR cooler pipes. REFER to ENGINE EMISSION CONTROL . REPAIR as necessary. TEST the system for normal operation.
Hissing noise - occurs during idle or high idle that is apparent with the hood open	Boost leak noise	USE the EngineEAR to locate the source. SCAN the air intake system from the inlet to each cylinder intake port. DISCARD the leaking parts, and INSTALL a new component.
	Composite intake manifold	Acceptable condition. Some composite manifolds exhibit this noise, which is the effect of the composite manifold.
Grinding noise - occurs during engine cranking	Incorrect starter motor mounting	INSPECT the starter motor for correct mounting. REFER to STARTING SYSTEM - DIESEL ENGINES . REPAIR as necessary. TEST the system for normal operation.
	Starter motor	CHECK the starter motor. REFER to STARTING SYSTEM - DIESEL ENGINES . REPAIR as necessary. TEST the system for normal operation.
	Incorrect starter motor drive engagement	INSPECT the starter motor drive for wear or damage. REFER to STARTING SYSTEM - DIESEL ENGINES . REPAIR as necessary. TEST the system for normal operation.
	Damaged flexplate	INSPECT the flexplate. REFER to FLEXPLATE INSPECTION . REPAIR as necessary. TEST the system for normal operation.
Engine noise, front of engine - knocking noise from lower front of engine	Damaged or separated crankshaft pulley/damper	CHECK for obvious signs of damage or wobble during operation. REFER to CRANKSHAFT PULLEY . REPAIR as necessary. TEST the system for normal operation.
Engine noise, front of engine - ticking, tapping or rattling noise from the front of the engine	Timing drive components	REMOVE the accessory drive belt. REFER to ACCESSORY DRIVE .
	Damaged oil pump	USE the EngineEAR to isolate the noise to the engine front cover. REMOVE the engine front cover and INSPECT the timing drive components and oil pump. REFER to ENGINE FRONT COVER . REPAIR as necessary. TEST the system for normal operation.
Engine noise, upper end - ticking noise near the fuel rail	Fuel injector	USE the EngineEAR to isolate the noisy injector(s). REFER to FUEL CHARGING AND CONTROLS - 6.7L DIESEL . REPAIR as necessary. TEST the system for normal operation.
Engine noise, upper end - ticking, knocking or rattle noise that occurs during idle or high idle during the first cold start of the day and may disappear as the engine warms	Valve train noise (bled down hydraulic lash adjuster)	CARRY OUT the VALVE TRAIN ANALYSIS . REPAIR as necessary. TEST the system for normal operation.
Engine noise, upper end - rattling noise from the valve train. Worse when the engine is cold	Low oil level	CHECK the oil level. FILL as necessary.
	Worn valve train components	CARRY OUT the VALVE TRAIN ANALYSIS . REPAIR as necessary. TEST the system for normal operation.
	Worn valve guides	CARRY OUT the VALVE GUIDE INNER DIAMETER procedure. REPAIR as necessary. TEST the system for normal operation.
	Excessive runout of the valve seats on the valve face	CARRY OUT the VALVE SEAT INSPECTION procedure. REPAIR as necessary. TEST the system for normal operation.
Engine noise, upper end - knocking or ticking noise, occurs mostly with a warm engine at idle	Low oil level	CHECK the oil level. FILL as necessary.
	Thin or diluted oil	INSPECT the oil for contamination. If the oil is contaminated, CHECK for the source. REPAIR as necessary. CHANGE the oil and filter.
	Incorrect oil viscosity	DRAIN the oil. REFILL with the proper viscosity oil for the climate.
	Damaged or incorrect oil filter	INSPECT the oil filter. INSTALL a new oil filter as necessary.
	Low oil pressure	CARRY OUT the OIL PRESSURE TEST . If not within specifications, GO to the LOW OIL PRESSURE TEST . REPAIR as necessary. TEST the system for normal operation.
Engine noise, lower end - ticking or knocking noise at engine front cover	Oil pump	USE the EngineEAR to verify the oil pump as the source of the noise at low RPM. INSTALL a new engine front cover. REFER to ENGINE FRONT COVER . TEST the system for normal operation.
Engine noise, lower end - light knocking noise, also described as piston slap. Noise is most noticeable when the engine is cold with light to medium acceleration. The noise disappears as the engine warms	Excessive clearance between the piston and the cylinder wall	CARRY OUT the PISTON TO CYLINDER BORE CLEARANCE procedure. REPAIR as necessary. TEST the system for normal operation.
Engine noise, lower end - light double knock or sharp rap sound. Occurs mostly with a warm engine at idle or low speeds in drive. Increases in relation to engine load. Associated with a poor lubrication history	Excessive clearance between the piston and the piston pin	CARRY OUT the PISTON INSPECTION procedure. REPAIR as necessary. TEST the system for normal operation.
Engine noise, lower end - light knocking noise. The noise is most noticeable when the engine is warm. The noise tends to decrease when the vehicle is coasting or in NEUTRAL	Excessive clearance between the connecting rod bearings and the crankshaft	CARRY OUT the CONNECTING ROD BEARING JOURNAL-TO-BEARING CLEARANCE procedure. REPAIR as necessary. TEST the system for normal operation.
Engine noise, lower end - deep knocking noise. The noise is most noticeable when the engine is warm, at lower RPM and under a light load and then at float	Worn or damaged crankshaft main bearings	CARRY OUT the CRANKSHAFT MAIN BEARING JOURNAL-TO-BEARING CLEARANCE procedure. REPAIR as necessary. TEST the system for normal operation.
Engine noise, rear of engine - knocking noise at rear of engine	Damaged flexplate	INSPECT the flexplate. REFER to FLEXPLATE INSPECTION . REPAIR as necessary. TEST the system for normal operation.
Engine vibration - vibration felt at all times	Excessive crankshaft pulley runout	CARRY OUT the CRANKSHAFT PULLEY RUNOUT CHECK . REFER to CRANKSHAFT PULLEY . REPAIR as necessary. TEST the system for normal operation.
Engine vibration - vibration felt at all times	Damaged or worn accessory drive component	CARRY OUT the Engine Accessory Test. REFER to NOISE, VIBRATION & HARSHNESS . INSPECT components and INSTALL new parts as necessary. REFER to ACCESSORY DRIVE . REPAIR as necessary. TEST the system for normal operation.
Engine vibration - at idle, a low-frequency vibration (5-20 Hz) or mild shake that is felt through the seat/floorpan	Cylinder misfire	CARRY OUT the Power Balance Test and the Relative Compression Test using the scan tool. REFER to INTRODUCTION - DIESEL MODELS . REPAIR as necessary. TEST the system for normal operation.
	Engine or torque converter out of balance	VERIFY the torque converter to crankshaft pilot clearance is correct. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - TORQSHIFT 6 . RE-INDEX the torque converter on the flexplate by 180 degrees. TEST the system for normal operation.
Engine vibration - is felt with increases and decreases in engine RPM	Powertrain mount(s)	CHECK the powertrain mounts for damage. For engine, REFER to ENGINE SUPPORT INSULATORS . For automatic transmission, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - TORQSHIFT 6 . REPAIR as necessary. TEST the system for normal operation.
	Engine or transmission contacting the chassis	INSPECT the powertrain/drivetrain for correct clearances. For engine, REFER to ENGINE SUPPORT INSULATORS . For automatic transmission, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - TORQSHIFT 6 . REPAIR as necessary. TEST the system for normal operation.
Engine vibration - increases intensity as the engine RPM is increased	Engine out-of-balance	CARRY OUT the Neutral Engine Run-Up (NERU) Test. REFER to NOISE, VIBRATION & HARSHNESS . ROTATE the torque converter 180 degrees. INSPECT the torque converter pilot outer diameter to crankshaft pilot inner diameter. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - TORQSHIFT 6 . REPAIR as necessary. TEST the system for normal operation.