Symptom Chart - Engine Noise/Vibration

WARNING: This page is about a different car, the 2004 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM CHART - ENGINE NOISE/VIBRATION

Condition	Possible Sources	Action
Grinding noise-occurs during engine cranking	Incorrect starter motor mounting.	INSPECT the starter motor for correct mounting. REPAIR as necessary. Refer to the appropriate ENGINE article.
	Starter motor.	CHECK the starter motor. REPAIR or INSTALL a new starter motor as necessary. REFER to STARTERS article.
	Incorrect starter motor drive engagement.	INSPECT the starter motor drive and flexplate/flywheel for wear or damage. INSTALL a new starter motor drive or flexplate/flywheel as necessary. REFER to STARTERS article.
Engine ticking noise	Fuel injector. Fuel line. Oil pump. Valve lifter. Belt tensioner. Water pump. Obstruction of cooling fan.	Go To PINPOINT TEST B: ENGINE TICKING NOISE
Engine drumming noise-normally accompanied by vibration	Powertrain mount.	CARRY OUT POWERTRAIN/DRIVETRAIN MOUNT NEUTRALIZING .
Engine drumming noise-normally accompanied by vibration	Damaged or misaligned exhaust system.	INSPECT the exhaust system for loose or broken clamps and brackets. CARRY OUT EXHAUST SYSTEM NEUTRALIZING .
Whistling noise-normally accompanied with poor idle condition	Air intake system.	CHECK the air intake ducts, air cleaner, throttle body and vacuum hoses for leaks and correct fit. REPAIR or ADJUST as necessary. REFER to INTAKE AIR DISTRIBUTION & FILTERING .
Clunking noise	Water pump has excessive end play or imbalance.	CHECK the water pump for excessive end play. INSPECT the water pump with the drive belt off for imbalance. INSTALL a new water pump as necessary. REFER to ENGINE COOLING .
Clunking noise	Generator has excessive end play.	CHECK the generator for excessive end play. REPAIR or INSTALL a new generator. REFER to GENERATORS & REGULATORS .
Pinging noise	Exhaust system leak.	INSPECT the exhaust system for leaks. REPAIR as necessary.
	Gasoline octane too low.	VERIFY with customer the type of gasoline used. CORRECT as necessary.
	Knock sensor operation.	CHECK the knock sensor. INSTALL a new knock sensor as necessary. REFER to ELECTRONIC ENGINE CONTROLS .
	Incorrect spark timing.	CHECK the spark timing. REPAIR as necessary.
	Foul-out spark plug.	CHECK the spark plugs. REPAIR or INSTALL new spark plugs as necessary.
	Catalytic converter.	Acceptable noise.
Knocking noise-light knocking noise, also described as piston slap. Noise is most noticeable when engine is cold with light to medium acceleration. Noise disappears as engine warms	Excessive clearance between the piston and the cylinder wall.	Engine cold and at high idle. Using an EngineEAR, pull a spark plug or fuel injector connector until the noise goes away. CARRY OUT a cylinder bore clearance to piston check. INSTALL a new piston. Refer to the appropriate ENGINE article.
Knocking noise-light double knock or sharp rap sound. Occurs mostly with warm engine at idle or low speeds in DRIVE. Increases in relation to engine load. Associated with poor lubrication history	Excessive clearance between the piston and the piston pin.	INSTALL a new piston or piston pin. Refer to the appropriate ENGINE article.
Knocking noise-light knocking noise is most noticeable when engine is warm. Noise tends to decrease when vehicle is coasting or in neutral	Excessive clearance between the connecting rod bearings and the crankshaft.	Engine warm and at idle. Using an EngineEAR, PULL a spark plug or fuel injector connector until the noise goes away. INSTALL new bearings. Refer to the appropriate ENGINE article.
Knocking-deep knocking noise. Noise is most noticeable when engine is warm, at lower RPM and under a light load and then at float	Worn or damaged crankshaft main bearings.	CARRY OUT Drive Engine Run-Up (DERU) Test. CHECK for noise with vehicle at operating temperature, during medium to heavy acceleration. CHECK at idle with injector disconnected, noise does not change. INSTALL new main bearings. Refer to the appropriate ENGINE article.
Knocking noise-occurs mostly with warm engine at light/medium acceleration	Spark plugs.	CHECK the spark plug for damage or wear. INSTALL new spark plugs as necessary.
	Carbon accumulation in combustion chamber.	REMOVE carbon from combustion chamber.
Whine or moaning noise	Air intake system.	CHECK the air cleaner and ducts for correct fit. INSPECT the air intake system for leaks or damage. REPAIR as necessary.
Whine or moaning noise	Generator electrical field or bearings.	CARRY OUT generator load test. REPAIR or INSTALL a new generator as necessary. REFER to GENERATORS & REGULATORS .
Drone type noise	Exhaust system.	CARRY OUT the EXHAUST SYSTEM NEUTRALIZING . REPAIR as necessary.
	A/C compressor.	CHECK for noise with vehicle at constant speeds. CYCLE the compressor on and off and listen for a change in pitch. REPAIR as necessary. REFER to AIR CONDITIONING .
	Powertrain mounts.	CARRY OUT the POWERTRAIN/DRIVETRAIN MOUNT NEUTRALIZING .
Sputter type noise - noise worse when cold, lessens or disappears when vehicle is at operating temperature	Damaged or worn exhaust system components.	INSPECT the exhaust system for leaks or damage. REPAIR as necessary. REFER to EXHAUST SYSTEM .
Rattling noise-noise from the upper engine (valve train). Worse when engine is cold	Low oil level.	CHECK oil level. FILL as necessary.
	Thin or diluted oil.	INSPECT the oil for contamination. If oil is contaminated, CHECK for the source. REPAIR as necessary. CHANGE the oil and filter.
	Low oil pressure.	CARRY OUT an oil pressure test. If not within specifications, REPAIR as necessary. REFER to ENGINE SYSTEM-GENERAL INFORMATION .
	Worn rocker arms/fulcrums or followers.	CARRY OUT a valve train analysis. INSTALL new valve train components as necessary. Refer to the appropriate ENGINE article.
	Worn valve guides.	CARRY OUT a valve train analysis. INSTALL new valve guides as necessary. Refer to the appropriate ENGINE article.
	Excessive runout of valve seats on the valve face.	CARRY OUT a valve seat runout test. INSPECT the valve face and seat. INSTALL new valves as necessary. Refer to the appropriate ENGINE article.
Rattling noise-from the bottom of the vehicle	Loose muffler shields or catalytic converter shields.	CHECK the exhaust system for loose shields. REPAIR as necessary.
Thumping noise-from the bottom of the vehicle, worse at acceleration	Exhaust pipe/muffler grounded to chassis.	CHECK the exhaust system to chassis clearance. CHECK the exhaust system hangers for damage. REPAIR as necessary. REFER to EXHAUST SYSTEM .
Whoosh-occurs during light vehicle acceleration. Heard inside the vehicle	Throttling late, creating turbulence transmitted through the plastic manifold.	CHECK for leaks or missing seal in the dash panel.
Engine vibration-increases intensity as engine RPM is increased	Engine out-of balance.	CARRY OUT Neutral Engine Run-Up (NERU) Test. ROTATE the torque converter, 120° for 3 bolt and 180° for 4 bolt. INSPECT the torque converter pilot outer diameter to crankshaft pilot inner diameter. REPAIR as necessary. REFER to AUTOMATIC TRANSMISSION - 5R44E & 5R55E .
Engine vibration-is felt with increases and decreases in engine RPM	Strain on exhaust mounts.	CARRY OUT the EXHAUST SYSTEM NEUTRALIZING . REPAIR as necessary. CHECK the powertrain/drivetrain mounts for damage. Refer to the appropriate ENGINE article. REPAIR as necessary. INSPECT the powertrain/drivetrain for correct clearances. REPAIR as necessary.
	Damaged or worn powertrain/drivetrain mounts	CHECK the powertrain/drivetrain mounts for damage. Refer to the appropriate ENGINE article. REPAIR as necessary.
	Engine or transmission grounded to chassis.	INSPECT the powertrain/drivetrain for correct clearances. REPAIR as necessary.
Engine vibration-vibration felt at all times	Excessive engine pulley runout.	CARRY OUT Engine Accessory Test. INSTALL a new engine pulley as necessary. Refer to the appropriate ENGINE article.
Engine vibration-vibration felt at all times	Damaged or worn accessory component.	CARRY OUT Engine Accessory Test. REPAIR or INSTALL a new component as necessary.
Accelerator pedal vibration-felt through the pedal as a buzz	Throttle cable loose or misrouted.	INSPECT the throttle cable. REPAIR as necessary. REFER to ACCELERATION CONTROL .
Engine vibration-mostly at coast/neutral coast. Condition improves with vehicle accelerating	Combustion instability.	CHECK the ignition system. INSTALL new components as necessary.
Engine vibration or shudder-occurs with light to medium acceleration above 56 km/h (35 mph)	Worn or damaged spark plugs.	INSPECT the spark plugs for cracks, high resistance or broken insulator. INSTALL a new spark plug(s) as necessary.
	Plugged fuel injector.	REPAIR or INSTALL a new injector as necessary.
	Damaged spark plug wire.	INSPECT the spark plug wires for damage. INSTALL a new spark plug wire(s) as necessary.
	Damaged spark plug wire.	INSPECT the spark plug wires for damage. INSTALL a new spark plug wire(s) as necessary.
	Contaminated fuel.	INSPECT the fuel for contamination. DRAIN the fuel system and refill.
	Worn or damaged torque converter.	CHECK the torque converter. INSTALL a new torque converter as necessary. REFER to AUTOMATIC TRANSMISSION - 5R44E & 5R55E .