Symptom Chart - Engine NVH

2010 Ford Mustang Base, 2D Coupe, AutomaticSECTION Symptom Chart - Engine NVH
NOTE: 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)
  • 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
  • Engine drumming noise - accompanied by vibration
  • Powertrain mount(s)
  • Rattle - occurs at idle or at light acceleration from a stop
  • Powertrain mount(s)
  • Whine/moan type noise - pitch increases or changes with vehicle speed
  • Powertrain mount(s)
  • Clunk - occurs when shifting from PARK or between REVERSE and DRIVE
  • Powertrain mounts
  • Idle speed is too high
  • CHECK for the correct idle speed.
  • 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
  • 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
  • Clunking noise
  • Coolant pump has excessive end play or imbalance
  • Whine or moaning noise
  • Air intake system
  • Whistling noise - normally accompanied with poor idle condition
  • Air intake system
  • Hissing noise - occurs during idle or high idle that is apparent with the hood open
  • Vacuum 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.
  • Vehicles with a plastic intake manifold
  • Acceptable condition. Some plastic manifolds exhibit this noise, which is the effect of the plastic manifold.
  • Grinding noise - occurs during engine cranking
  • Incorrect starter motor mounting
  • Starter motor
  • Incorrect starter motor drive engagement
  • Engine noise, front of engine - knocking noise from lower front of engine
  • Damaged or separated crankshaft pulley/damper
  • Engine noise, front of engine - ticking, tapping or rattling noise from the front of the engine
  • Timing drive components
  • Engine noise, upper end - ticking noise near the fuel rail and intake manifold
  • Fuel rail clip
  • Fuel injector
  • 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 lifter/lash adjuster)
  • Engine noise, upper end - occurs mostly with a warm engine at light/medium acceleration
  • Worn or damaged spark plugs
  • Carbon accumulation in combustion chamber
  • INSPECT the cylinder using a Bore scope. ELIMINATE carbon buildup.
  • 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
  • Worn valve guides
  • Excessive runout of the valve seats on the valve face
  • Engine noise, upper end - pinging noise
  • Gasoline octane too low
  • VERIFY with customer the type of gasoline used. CORRECT as necessary.
  • Knock Sensor (KS) operation
  • Incorrect spark timing
  • High operating temperature
  • INSPECT the cooling system for leaks. CHECK the coolant level. REFILL as necessary. CHECK the coolant for the correct mix ratio. DRAIN and REFILL as needed. VERIFY the engine operating temperature is within specifications. REPAIR as necessary. Refer to the ENGINE - 4.0L SOHC , ENGINE - 4.6L (3V) , and ENGINE - 5.4L (4V) for the procedure.
  • Spark plug
  • Catalytic converter
  • Acceptable noise.
  • 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.
  • Damaged or incorrect oil filter
  • INSPECT the oil filter. INSTALL a new oil filter as necessary.
  • Low oil pressure
  • Camshaft phaser and sprocket(s) [VCT  engines only]
  • Engine noise, lower end - ticking or knocking noise near the oil filter adapter
  • Oil pump
  • 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
  • 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
  • Excessive clearance between the piston and the connecting rod
  • 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
  • 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
  • Engine noise, rear of engine - knocking noise at rear of engine
  • Damaged flywheel/flexplate
  • Engine vibration - vibration felt at all times
  • Excessive crankshaft pulley runout
  • Damaged or worn accessory component
  • CARRY OUT the Engine Accessory Test. REPAIR or INSTALL a new component as necessary.
  • Engine vibration - at idle, a low-frequency vibration (5-20 Hz) or mild shake that is felt through the seat/floorpan
  • Cylinder misfire
  • Engine or torque converter out of balance
  • VERIFY the torque converter to crankshaft pilot clearance is correct. REPAIR as necessary. RE-INDEX the torque converter on the flexplate by 120 degrees for a 3-bolt converter or 180 degrees for a 4-bolt converter. Refer to the IN-VEHICLE REPAIR for the procedure.
  • Engine vibration - is felt with increases and decreases in engine RPM
  • Powertrain mount(s)
  • Engine or transmission contacting the chassis
  • INSPECT the powertrain/drivetrain for correct clearances. REPAIR as necessary.
  • 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, 120 degrees for 3-bolt or 180 degrees for 4-bolt. INSPECT the torque converter pilot outer diameter to crankshaft pilot inner diameter. REPAIR as necessary. Refer to the IN-VEHICLE REPAIR for the procedure.
  • Engine vibration - mostly at coast/neutral coast. Condition improves with vehicle acceleration
  • Combustion instability
  • Engine vibration or shudder - occurs with light to medium acceleration above 56 km/h (35 mph)
  • Worn or damaged spark plugs
  • Plugged fuel injector
  • Contaminated fuel
  • INSPECT the fuel for contamination. DRAIN the fuel system and refill.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.