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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 1795 (Noise, Vibration And Harshness - F-150 & Mark LT) >> Diagnostic Tests >> Noise, Vibration and Harshness (NVH) >> Symptom Charts

Symptom Charts

WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Symptom Chart - Air Leak and Wind Noise

Condition Possible Sources Action
  • Air leak around door perimeter
  • Loose fit seal
  • PINCH the seal carrier to improve retention on the seal flange.
 
  • Seal installed incorrectly
  • REINSTALL the seal.
 
  • Door misaligned
  • REALIGN the door. CHECK door gaps and fit in the door opening and ADJUST as necessary.
 
  • Scuff plate installed incorrectly
  • REINSTALL the scuff plate.
 
  • Seal or seal push pins damaged
  • INSTALL a new seal.
  • Air leak around glass run
  • Door glass misaligned
  • ADJUST the door glass.
 
  • Glass run installed incorrectly
  • ADJUST the glass run. INSERT foam in the glass run carrier.
 
  • Leak path behind glass run
  • INSTALL foam rope behind the glass run.
 
  • Glass run channel spread wide
  • PINCH the glass run channel to reduce the size of the opening.
 
  • Blow-out clip bent or contacting door glass
  • ADJUST the blow-out clip or INSTALL a new glass run/blow-out clip molding assembly.
 
  • Glass run damaged
  • INSTALL a new glass run.
  • Air leak at inner belt line
  • Belt line seal installed incorrectly on flange
  • ADJUST the seal. (Do not bend the flange.)
 
  • Belt line seal integrated with door trim installed incorrectly (no glass contact)
  • REINSTALL the door trim.
 
  • No contact with side glass
  • ADJUST the door glass.
 
  • No contact with glass runs at both ends of belt line seal
  • ADJUST the belt line seal or ADD foam at the seal ends.
 
  • Belt line seal damaged
  • INSTALL a new seal.
  • Air leak at outer belt line
  • Belt line seal installed incorrectly on flange (no glass contact)
  • ADJUST the seal.
 
  • Belt line seal does not contact the glass
  • ADJUST the door glass.
 
  • No contact with glass runs at both ends of belt line seal
  • ADJUST the belt line seal/ADD foam at the seal ends.
 
  • Belt line seal damaged
  • INSTALL a new seal.
  • Draft at inner door handle/speaker opening
  • Hole in watershield
  • SEAL the hole with a suitable tape.
 
  • Watershield misaligned
  • REALIGN the watershield. INSTALL a new watershield if the pressure sensitive adhesive fails.
 
  • Exterior door handle seal misaligned/damaged
  • REALIGN or INSTALL a new seal as necessary.
  • Wind noise from side view mirror
  • Outside mirror housing misaligned
  • REALIGN with the edges shingled correctly and no gaps.
 
  • Mirror sail gasket folded/misaligned
  • REINSTALL with the gasket unfolded and aligned correctly.
 
  • Mirror housing trim cap installed incorrectly
  • REINSTALL with the edges shingled to the air flow.
 
  • Air leak through mirror housing hinge
  • Fully ENGAGE the mirror into its operating position/USE foam to block the air path through the hinge.
 
  • Inner sail trim installed incorrectly
  • REINSTALL the sail trim/ADJUST the door trim.
 
  • Inner sail gasket/barrier installed incorrectly
  • REINSTALL the trim cover with the gasket/barrier aligned correctly.
 
  • Air path through wiring bundle/fastener access holes
  • BLOCK the air path(s) with foam/tape.
 
  • Exposed fastener access hole on mirror housing/sail
  • INSTALL a new cap if it is missing.
  • Air leak around perimeter of fixed glass
  • Gaps in the sealant bead
  • APPLY approved sealant.
 
  • Air traveling up windshield molding along A-pillar
  • INSTALL foam rope the full length of the A-pillar.
 
  • Windshield/backlite misaligned or not installed correctly
  • REINSTALL the windshield/backlite.
 
  • Rear hood seal at base of windshield misaligned/damaged
  • REALIGN or INSTALL a new seal as necessary.
  • Air leak at cowl
  • Cowl gasket misaligned/damaged
  • REALIGN or INSTALL a new seal as necessary.
  • Air leak around liftgate perimeter
  • Loose fit seal
  • PINCH the seal carrier to improve retention on the seal flange or INSERT foam in the carrier.
 
  • Seal misaligned
  • REINSTALL the seal.
 
  • Liftgate misaligned
  • REALIGN the liftgate. CHECK the liftgate fit in the body opening and ADJUST as necessary.
 
  • Scuff plate misaligned
  • REINSTALL the scuff plate.
 
  • Seal or seal push pins damaged
  • INSTALL a new seal.
  • Air leak around the liftgate flip window perimeter
  • Loose fit seal
  • PINCH the seal carrier to improve the retention to the seal flange.
 
  • Seal misaligned
  • REINSTALL the seal.
 
  • Glass misaligned
  • REALIGN the glass.
 
  • Seal damaged
  • INSTALL a new seal.
  • Wind noise from antenna
  • Shape of antenna
  • INSTALL an antenna boot or a spiral antenna.
 
  • Air leak around antenna cable access hole
  • INSPECT the antenna access hole grommet. REPAIR as necessary.
  • Air leak from closed roof opening panel
  • Seal installed incorrectly
  • REINSTALL the seal.
 
  • Roof opening panel glass/door misaligned
  • REALIGN the roof opening panel glass/door.
 
  • Roof opening panel damaged
  • INSTALL a new roof opening panel.
  • Buffeting from an open roof opening panel
  • Wind deflector inoperative/damaged
  • REPAIR or INSTALL a new wind deflector as necessary.
 
  • Wind deflector height incorrect
  • ADJUST the wind deflector higher.
  • Wind noise created by airflow over or behind body panels
  • Fender splash shield misaligned
  • REALIGN the fender splash shield.
 
  • Body panel misaligned (exposed edge)
  • REALIGN the appropriate body panel.
 
  • Hood misaligned (front margin)
  • CHECK hood gaps and fit. ADJUST the hood as necessary.
 
  • Front grille edge noise
  • APPLY foam in the hollow areas behind the louvers.
  • Wind noise created by grille opening panel
  • Grille relationship to leading edge on hood
  • ADJUST the grille opening panel forward to eliminate wind noise.
 
  • Sharp edges due to material imperfections
  • REMOVE the sharp edges (no damage to visible surface).
  • Wind noise from air extractor
  • Air extractor housing seated incorrectly
  • REINSTALL the air extractor housing.
 
  • Air extractor housing or flaps damaged
  • INSTALL a new air extractor.
  • Air leak at top of A-pillar - vehicles with a convertible top
  • Seal at windshield header installed incorrectly
  • REINSTALL the seal.
 
  • Seal pinched
  • FILL the seal with foam to reshape it.
 
  • Gap between side rail and header seal at A-pillar
  • ADJUST the J-hook/vinyl top.
  • Air leak at rear quarter glass (division bar) - vehicles with a convertible top
  • No contact between front side glass and quarter glass division bar
  • ADJUST the front side glass regulator and the rear quarter glass regulator.
  • Air leak or wind noise from top of side glass - vehicles with a convertible top
  • Gap between side rail and vinyl top
  • ADD additional foam tape to seal between the side rail and the vinyl top.
 
  • Seal at windshield header installed incorrectly
  • REINSTALL the seal.
 
  • Seal damaged between side rail and vinyl top
  • INSTALL a new seal.
 
  • Vinyl top damaged
  • INSPECT the vinyl top. INSTALL a new vinyl top as necessary.
  • Air leak or wind noise at windshield header - vehicles with a convertible top
  • Vinyl top not flush with header
  • ADJUST the J-hook to lower the top to achieve a flush condition.
 
  • Seal at windshield header installed incorrectly
  • Header seal not flush with header
  • REINSTALL the seal.
  • Convertible top flapping with the top up
  • Vinyl top contacting interior headliner
  • Working from front to back, INSTALL a 6.35 mm (0.25 in) foam sheet between the headliner and the vinyl top at the suspected area. Allow a clearance of 50 mm (2 in) - 75 mm (3 in) away from the roof bows and the side rails.
  • Noise from roof rack
  • Roof rack rails or crossbars loose
  • TIGHTEN the fasteners.
 
  • Roof rack fasteners missing
  • INSTALL the approved fasteners.
 
  • Roof rack crossbars installed backward
  • REINSTALL the crossbars.
 
  • Roof rack rub strips partially lifting from roof
  • REAPPLY adhesive or fasteners or INSTALL new rub strips as necessary.
 
  • Roof rack gaskets loose or misaligned
  • REINSTALL the gasket.
  • Wind noise from bug shield/exterior windshield sun visor
  • Turbulence created by location and shape
  • REMOVE per customer direction if it is a dealer installed option.
Symptom Chart - Brake Noise/Vibration

Condition Possible Sources Action
  • Rattling noise
  • Caliper mounting bolts loose
  • CHECK the caliper bolts. TIGHTEN to specifications. REFER to FRONT DISC BRAKE article for the front disc brake pads or REAR DISC BRAKE article for the rear disc brake pads.
 
  • Damaged or worn caliper pins or retainers
  • CHECK the caliper pins and retainers for lubrication and correct fit. LUBRICATE or INSTALL new components as necessary. REFER to FRONT DISC BRAKE article for the front disc brake pads or REAR DISC BRAKE article for the rear disc brake pads.
 
  • Missing or damaged anti-rattle clips or springs
  • CHECK the brake pads for missing clips or broken springs. INSTALL new components as necessary. REFER to FRONT DISC BRAKE article for the front disc brake pads or REAR DISC BRAKE article for the rear disc brake pads.
 
  • Loose brake disc shield
  • Clicking noise - with brakes applied with ABS brakes
  • ABS hydraulic control unit
  • Acceptable condition.
  • Squealing noise - occurs on first (morning) brake application
  • Disc brake pads
  • Acceptable condition. Caused by humidity and low disc brake pad temperature.
  • Squealing noise - a continuous squeal
  • Disc brake pads or linings worn below minimum thickness
  • Squealing noise - an intermittent squeal brought on by cold, heat, water, mud or snow
  • Disc brake pad
  • Acceptable condition.
  • Groaning noise - occurs at low speeds with brake lightly applied (creeping)
  • Disc brake pads
  • Acceptable condition.
  • Grinding noise - continuous
  • Disc brake pads or linings worn below minimum thickness
  • INSPECT the disc brake pads, brake discs/drums and attaching hardware for damage. REPAIR or INSTALL new components as necessary. REFER to FRONT DISC BRAKE article for the front disc brake pads or REAR DISC BRAKE article for the rear disc brake pads.
  • Moaning noise
  • Brake linings contaminated with grease or oil
  • INSPECT the brake pads and shoes for contamination. REPAIR or INSTALL new components as necessary. REFER to FRONT DISC BRAKE article for the front disc brake pads or REAR DISC BRAKE article for the rear disc brake pads.
  • Brake vibration/shudder - occurs when brakes are applied
  • Uneven disc or drum wear
  • Uneven disc brake pad or lining transfer
  • Suspension components
  • Brake vibration/shudder - occurs when the brake pedal is released
  • Brake drag
  • INSPECT the disc brake pads or linings for premature wear. REPAIR or INSTALL a new caliper or wheel cylinder as necessary. REFER to FRONT DISC BRAKE article for the front disc brake pads or REAR DISC BRAKE article for the rear disc brake pads.
Symptom Chart - Driveline Noise/Vibration

Condition Possible Sources Action
  • Axle howling or whine - front or rear axle
  • Axle lubricant low
  • CHECK the lubricant level. FILL the axle to specification.
 
  • Axle housing damage
 
  • Damaged or worn wheel bearings or axle bearings
  • CHECK for abnormal wheel bearing play or roughness. Refer to Wheel Bearing Check  in this article. ADJUST or INSTALL new wheel bearings as necessary.
 
  • Damaged or worn differential ring and pinion
 
  • Damaged or worn differential side or pinion bearings
 
  • Damaged or worn differential side gears and pinion gears
  • Front axle groan, hum or vibration - occurs when operated in 2 HIGH
  • Front drive axle halfshaft rotational speed variance
  • REFER to component test Front Drive Axle Halfshaft Rotation Speed in this article.
  • Driveline clunk - loud clunk when shifting from REVERSE to DRIVE
  • Incorrect axle lubricant level
  • CHECK the lubricant level. FILL the axle to specification.
 
  • Excessive backlash in the axle or transmission
 
  • Damaged or worn pinion bearings
 
  • Damaged or worn universal joints (U-joints)
  • INSPECT the U-joints for wear or damage. INSTALL new U-joints as necessary. REFER to DRIVESHAFT article.
 
  • Loose suspension components
  • INSPECT the suspension for damage or wear. REPAIR or INSTALL new components as necessary.
 
  • Broken powertrain mounts
 
  • Idle speed too high
  • CHECK for the correct idle speed.
  • Driveline clunk - occurs as the vehicle starts to move forward following a stop
  • Worn or galled driveshaft slip-yoke splines
  • CLEAN and INSPECT the splines of the yoke for a worn or galled condition. INSTALL a new yoke as necessary. REFER to DRIVESHAFT article.
 
  • Worn or galled driveshaft and coupling shaft splines
  • CLEAN and INSPECT the splines of the driveshaft and coupling shaft for a worn or galled condition. INSTALL a new driveshaft assembly as necessary. REFER to DRIVESHAFT article.
 
  • Loose rear leaf spring U-bolts
  • Driveline clunk (4WD vehicles) - occurs during shift-on-the-fly engagement
  • Clutch relay
  • Shift motor
  • Transfer case
  • 4WD module
  • Clicking, popping or grinding - occurs while vehicle is turning
  • Brake components
 
  • Steering components
  • INSPECT the drag link, inner and outer tie-rods or idler arm for wear or damage. REPAIR as necessary.
 
  • Suspension components
 
  • Damaged or worn wheel bearings
  • CHECK for abnormal wheel bearing play or roughness. Refer to Wheel Bearing Check  in this article. ADJUST or INSTALL new wheel bearings as necessary.
  • High pitched chattering - noise from the rear axle when the vehicle is turning
  • Incorrect or contaminated lubricant
  • CHECK the vehicle by driving in tight circles (5 clockwise, 5 counterclockwise). FLUSH and REFILL with the specified rear axle lubricant and friction modifier as necessary.
 
  • Damaged or worn differential (differential side gears and pinion gears)
  • Buzz - buzzing noise is the same at cruise or coast/deceleration
  • Damaged or worn tires
  • CHECK for abnormal tire wear or damage. INSTALL a new tire as necessary. REFER to WHEELS AND TIRES article.
 
  • Incorrect driveline angles
  • Rumble or boom - noise occurs at coast/deceleration, usually driveshaft speed related and noticeable over a wide range of speeds
  • Driveshaft is out-of-balance
  • CHECK the driveshaft for damage, missing balance weights or undercoating. CHECK the driveshaft balance. CARRY OUT a driveline vibration test. REFER to DRIVELINE SYSTEM - GENERAL INFORMATION article.
 
  • U-joints binding or seized
  • ROTATE the driveshaft and CHECK for rough operation or seized U-joints. INSTALL new U-joints as necessary. REFER to DRIVESHAFT article.
 
  • Excessive pinion flange runout
  • Grunting - normally associated with a shudder experienced during acceleration from a dead stop
  • Driveshaft slip yoke binding
  • CLEAN and LUBRICATE the male and female splines.
 
  • Loose rear spring U-bolts
  • Howl - can occur at various speeds and driving conditions. Affected by acceleration and deceleration
  • Incorrect ring and pinion contact, incorrect bearing preload or gear damage
  • Chuckle - heard at coast/deceleration. Also described as a knock
  • Incorrect ring and pinion contact or by damaged teeth on the coast side of the ring and pinion
  • Knock - noise occurs at various speeds. Not affected by acceleration or deceleration
  • Gear tooth damage to the drive side of the ring and pinion
 
  • Excessive axle shaft end play (Vehicles with integral axles)
  • Scraping noise - a continuous low pitched noise starting at low speeds
  • Worn or damaged pinion bearings
  • Driveline shudder - occurs during acceleration from a slow speed or stop
  • Rear drive axle assembly mispositioned
  • CHECK the axle mounts and the rear suspension for damage or wear. REPAIR as necessary.
 
  • Loose rear spring U-bolts
 
  • Incorrect or high CV joint operating angle
  • CHECK vehicle ride height is within limits. REPAIR as necessary.
 
  • Damaged or worn front suspension components
  • CHECK for a loose stabilizer bar, damaged or loose strut/strut bushings or loose or worn ball joints. INSPECT the steering linkage for wear or damage. REPAIR or INSTALL new components as necessary.
 
  • Driveline angles out of specification
 
  • U-joints binding or seized
  • ROTATE the driveshaft and CHECK for rough operation or seized U-joints. INSTALL new U-joints as necessary. REFER to DRIVESHAFT article.
 
  • Binding, damaged or galled splines on the driveshaft slip-yoke
  • CLEAN and INSPECT the splines of the slip-yoke, driveshaft and coupling shaft for a worn, damaged or galled condition. INSTALL a new slip-yoke or driveshaft assembly as necessary. REPAIR as necessary. REFER to DRIVESHAFT article.
  • Driveline vibration - occurs at cruising speeds
  • U-joints are worn
  • CHECK for wear or incorrect seating. INSTALL new U-joints as necessary. REFER to DRIVESHAFT article.
 
  • Worn or damaged driveshaft center bearing support
  • CHECK the insulator for damage or wear. ROTATE the driveshaft and CHECK for rough operation. INSTALL a new center bearing support as necessary. DRIVESHAFT article.
 
  • Loose axle pinion flange bolts
  • INSPECT the axle pinion flange. TIGHTEN the pinion flange bolts to specification. REFER to DRIVESHAFT article.
 
  • Excessive axle pinion flange runout
 
  • Driveshaft is out-of-balance
  • CHECK the driveshaft for damage, missing balance weights or undercoating. CHECK driveshaft balance. CARRY OUT a driveline vibration test. REFER to DRIVELINE SYSTEM - GENERAL INFORMATION article. REPAIR as necessary.
 
  • Binding or damaged splines on the driveshaft slip-yoke
  • CLEAN and INSPECT the splines of the slip-yoke, driveshaft and coupling shaft for wear or damage. INSTALL a new slip-yoke or driveshaft assembly as necessary. REFER to DRIVESHAFT article. REPAIR as necessary.
 
  • Driveshaft runout
 
  • Incorrect lateral and radial tire/wheel runout
  • INSPECT the tire and wheels. MEASURE tire runouts. REPAIR or INSTALL new components as necessary. REFER to WHEELS AND TIRES article.
 
  • Driveline angles out of specification
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 STARTING SYSTEM article.
 
  • Starter motor
  • CHECK the starter motor. REPAIR or INSTALL a new starter motor as necessary. REFER to STARTING SYSTEM article.
 
  • Incorrect starter motor drive engagement
  • INSPECT the starter motor drive and flywheel/flexplate for wear or damage. INSTALL a new starter motor drive or flywheel/flexplate as necessary. REFER to STARTING SYSTEM article.
  • Engine ticking noise
  • Fuel injector
  • Fuel line
  • Oil pump
  • Valve lifter
  • Belt tensioner
  • Water pump
  • Obstruction of cooling fan
  • Engine drumming noise - normally accompanied by vibration
  • Powertrain mount
 
  • Damaged or misaligned exhaust system
  • Whistling noise - normally accompanied with poor idle condition
  • Air intake system
  • 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 article.
 
  • Generator has excessive end play
  • 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
 
  • Incorrect spark timing
  • CHECK the spark timing. REPAIR as necessary.
 
  • High operating temperature
  • INSPECT cooling system for leaks. CHECK the coolant level. REFILL as necessary. CHECK the coolant for the correct mix ratio. DRAIN and REFILL as needed. CHECK engine operating temperature is within specifications. 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 ENGINE - 4.2L article, ENGINE - 4.6L (2V) article or ENGINE - 5.4L (3V) 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
  • 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
  • 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 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 ENGINE - 4.2L article, ENGINE - 4.6L (2V) article or ENGINE - 5.4L (3V) 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.
 
  • Generator electrical field or bearings
  • Drone type noise
  • Exhaust system
 
  • A/C compressor
 
  • Powertrain mounts
  • 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 article.
  • 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
 
  • Worn rocker arms/fulcrums or followers
 
  • Worn valve guides
 
  • Excessive runout of valve seats on the valve face
  • Rattling noise - from the bottom of the vehicle
  • Loose muffler shields or catalytic converter shields
  • CHECK the exhaust system for loose exhaust 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 article.
  • 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 TRANSAXLE/TRANSMISSION - 4R70E/4R75E article.
  • Engine vibration - is felt with increases and decreases in engine rpm
  • Strain on exhaust mounts
 
  • Damaged or worn powertrain/drivetrain mounts
 
  • 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
 
  • 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
  • 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.
 
  • Contaminated fuel
  • INSPECT the fuel for contamination. DRAIN the fuel system and refill.
 
  • Worn or damaged torque converter
Symptom Chart - Idle Noise/Vibration

Condition Possible Sources Action
  • Idle air control (IAC) valve moan - occurs on throttle tip-out
  • IAC valve is contaminated with oil
  • Go to Component Tests in this article.
  • Accessory drive belt chirp - occurs at idle or high idle, cold or hot. Most common occurrence is during humid weather.
  • Accessory drive belt worn, or pulley is misaligned or loose
  • INSPECT for loose or misaligned pulleys. CHECK the drive belt for wear or damage. INSTALL new pulley(s)/accessory drive belt, as necessary. REFER to ACCESSORY DRIVE article.
  • Accessory drive bearing hoot - occurs at idle or high idle in cold temperatures of approximately +4°C (+40°F) or colder at first start of the day
  • Accessory drive idler or tensioner pulley bearing is experiencing stick/slip between ball bearings and bearing race
  • Power steering moan - occurs at high idle and possibly at idle during the first cold start of the day in temperatures of approximately -18°C (0°F) or colder. Noise can even be a severe screech for less than one minute in very cold temperatures of approximately -29°C (-20°F) or colder
  • High fluid viscosity, or plugged reservoir screen in power steering reservoir starves pump causing cavitation
  • Generator whine - during high electrical loads at idle or high idle, a high pitch whine or moan is emitted from the generator
  • Generator electrical field noise
  • Using an EngineEAR, PROBE near the generator housing. LISTEN for changes in the noise level while changing electrical loads (such as rear defrost, headlamps, etc.). CARRY OUT a generator load test. If the system passes the load test, the noise is from the generator bearings, INSTALL new bearings. If the system fails the load test, INSTALL a new generator. REFER to CHARGING SYSTEM - GENERAL INFORMATION article.
  • Engine-driven cooling fan moan - occurs during the first start of the day. It is most objectionable near idle speeds up to 2000 rpm. The noise increases with rpm
  • The viscous cooling fan clutch engages until the fluid in the clutch reaches normal operating temperature, causing the fan to fully engage
  • Drumming noise - occurs inside the vehicle during idle or high idle, hot or cold. Very low-frequency drumming is very rpm dependent
  • Exhaust system vibration excites the body resonances inducing interior noise
  • Engine vibration excites the body resonances inducing interior noise
  • Hissing noise - occurs during idle or high idle that is apparent with the hood open
  • Vacuum leak or idle air control (IAC) valve flow noise
  • Use the Ultrasonic Leak Detector/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.
  • Automatic transmission buzz or hiss
  • Incorrect driveline angles
 
  • Worn or damaged main control solenoids or valves
  • Manual Transmission Clutch throw-out bearing whine. A change in noise pitch or loudness while depressing the clutch pedal
  • Worn throw-out bearing
  • INSTALL a new throw-out bearing.
  • Heating, vacuum and air conditioning (HVAC) system chirp - most audible inside the vehicle. Listen for a change in noise pitch or loudness while changing the HVAC system blower speed
  • Damaged or worn HVAC blower bearing
  • INSTALL a new blower motor.
  • Air conditioning (A/C) clutch ticking - occurs when the compressor clutch engages
  • Acceptable noise
  • Incorrect air gap
  • LISTEN to the clutch to determine if the noise occurs with clutch engagement. A small amount of noise is acceptable. If the noise is excessive, CHECK the A/C clutch air gap. INSPECT the A/C clutch for wear or damage. INSTALL a new clutch as necessary.
  • Intermittent rattle, or scraping/rubbing noise
  • Loose exhaust heat shield(s)
  • INSPECT the exhaust system for loose parts using a glove or clamps to verify cause. REPAIR as necessary. REFER to EXHAUST SYSTEM article.
 
  • Wiring, hose or other part interfering with accessory drive, drive belt or pulley
  • INSPECT accessory drive system closely verifying there is adequate clearance to all rotating components. REPAIR as necessary.
  • Engine ticking or knocking noise - occurs during idle or high idle during the first cold start of the day
  • Piston noise or valve train noise (bled down lifter/lash adjuster)
  • A continuous, speed-dependent rattle from the engine - occurs during idle or high idle during the first cold start of the day and disappears as the engine warms up
  • Piston noise or valve train noise (bled down lifter/lash adjuster)
  • Idle vibration - 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 flex plate by 120° on a 3 bolt converter or 180° for a 4 bolt converter. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article. RETEST the vehicle.
  • Idle vibration - a high-frequency vibration (20-80 Hz) or buzz, that is felt through the steering wheel or seat
  • Exhaust system mounts bound up
  • VERIFY concern occurs at engine firing frequency. CHECK that the exhaust system vibrates at the same frequency as the engine. ADD 9-14 km (20-30 lb.) to the tail pipe to test, CARRY OUT Exhaust System Neutralizing  in this article.
 
  • Body mounts loose
  • INSPECT the body mounts. CARRY OUT a Neutral Engine Run-Up (NERU) Test. REPAIR as necessary
 
  • Power steering lines grounded out
  • INSPECT that the power steering lines are not contacting the chassis or each other. REPAIR as necessary.
Symptom Chart - Squeak and Rattle

Condition Possible Sources Action
  • Squeak - heard inside the vehicle when closing/opening the door
  • Insufficient lubrication on the door hinge or check strap
  • LUBRICATE the hinge or check strap.
 
  • Internal door components loose, rubbing or misaligned
  • CHECK the inside of the door. TIGHTEN or ALIGN as necessary. USE the Rotunda Squeak and Rattle Kit to isolate any rubbing components.
  • Squeak - heard inside the vehicle when closing/opening the window
  • Worn or damaged glass run/channel
  • Squeak - heard outside of vehicle when closing/opening the door
  • Exhaust shield rubbing against the chassis or exhaust pipe
  • CHECK the exhaust system. REPAIR as necessary. EXHAUST SYSTEM article.
  • Squeak - occurs with initial brake pedal application
  • Disc brake pads
  • Under certain conditions, asbestos free pads can generate a squeak noise. This noise is normal and does not indicate a concern.
  • Squeak - a constant noise that occurs with brake pedal applications
  • Damaged or worn disc brake pads
  • INSPECT the pads for oil, grease or brake fluid contamination. CHECK for glazed linings. A brake disc with hard spots will also cause a squeak type noise. REPAIR or INSTALL new pads as necessary. REFER to FRONT DISC BRAKE article for the front disc brake pads or REAR DISC BRAKE article for the rear disc brake pads.
  • Squeak - noise occurs over bumps or when turning
  • Worn control arm bushings
 
  • Worn or damaged shock absorber/strut
  • Rattle - heard when closing/opening the door or window
  • Loose internal door mechanism, bracket or attachment
  • REPEAT the motion or CARRY OUT a "tap test" to duplicate the noise. INSPECT the door for loose components. TIGHTEN loose components or USE the Rotunda Squeak and Rattle Kit to isolate any rattling components.
  • Squeak or rattle - heard inside the vehicle over rough roads/bumps
  • Misaligned glove compartment door/hinge
  • ALIGN the glove compartment door.
 
  • Instrument panel trim loose or misaligned
  • INSPECT the instrument panel trim for missing or loose clips or screws. REPAIR as necessary.
 
  • Loose interior component or trim
  • CARRY OUT a "touch test". ELIMINATE the noise by pressing or pulling on interior trim and components. USE the Rotunda Squeak and Rattle Kit to isolate any rattling/squeaking components.
  • Squeak or rattle - noise with a vibration concern
  • Damaged or worn body mounts
  • INSPECT the upper and lower absorbers and washers for damage or wear. CHECK the body mount brackets for damage. CHECK the nuts and bolts are tightened to specifications. TIGHTEN as necessary.
 
  • Damaged or worn subframe mounts
  • INSPECT the upper and lower absorbers for damage or wear. CHECK the sub-frame for damage. CHECK the nuts and bolts are tightened to specifications. TIGHTEN as necessary.
Symptom Chart - Steering Noise/Vibration

Condition Possible Sources Action
  • Steering grunt or shudder - occurs when turning into or out of a turn at low speeds (temperature sensitive)
  • Steering gear or power steering hoses
  • Go to Steering Gear Grunt/Shudder Test component test in this article.
  • Steering System clonk - hydraulic knocking sound
  • Air in the steering hydraulic system
  • Power steering pump moan - loud humming noise occurs when the steering wheel is rotated to the stop position. Produces a 120-600 Hz frequency that changes with rpm
  • Power steering hose grounded out to chassis
  • INSPECT the power steering hoses. REPAIR as necessary.
 
  • Aerated fluid
 
  • Steering gear isolators
  • INSPECT the isolators for wear or damage. REPAIR as necessary.
 
  • Low fluid
  • CHECK the fluid level. REFILL as necessary.
 
  • Power steering pump brackets loose or misaligned
  • Steering gear clunk - occurs only while cornering over a bump (can be temperature sensitive)
  • Steering gear
  • Feedback (rattle, chuckle or knocking noise in the steering gear) - a condition where roughness is felt in the steering wheel when the vehicle is driven over rough surfaces
  • Column intermediate/flexible shaft joints damaged or worn
  • INSTALL a new intermediate/flexible shaft. REFER to STEERING COLUMN article.
 
  • Loose, damaged or worn tie-rod ends
  • TIGHTEN the nuts to specification or INSTALL new tie-rod ends as necessary. REFER to POWER STEERING article.
 
  • Steering gear insulators or mounting bolts loose or damaged
 
  • Steering column intermediate shaft bolts are loose
 
  • Steering column damaged or worn
  • REPAIR or INSTALL a new steering column as necessary. REFER to STEERING COLUMN article.
 
  • Loose suspension bushings, bolts or ball joints
  • Feedback (nibble at the steering wheel) - a condition where slight rotational movement is felt in the steering wheel when the vehicle is driven over rough or grooved surfaces
  • Lateral runout in the tire or wheel
 
  • Yoke spring in the steering gear
  • CHECK TSBs for revised yoke spring for applicable vehicles.
  • Accessory drive belt squeal/chirp - when rotating the steering wheel from stop to stop
  • Loose or worn accessory drive belt
  • ADJUST or INSTALL a new accessory drive belt as necessary. REFER to ACCESSORY DRIVE article.
  • Power steering gear hiss
  • Steering column intermediate/flexible shaft-to-steering gear is binding or misaligned
  • REPAIR or INSTALL a new intermediate/flexible shaft as necessary. REFER to STEERING COLUMN article.
 
  • Grounded or loose steering column boot at the dash panel
  • REPAIR as necessary.
 
  • Damaged or worn steering gear input shaft and valve
  • REPAIR or INSTALL a new steering gear as necessary. REFER to POWER STEERING article.
  • Steering column rattle
  • Loose bolts or attaching brackets
  • TIGHTEN the bolts to specifications.
 
  • Loose, worn or insufficiently lubricated column bearings
  • LUBRICATE or INSTALL new steering column bearings as necessary. REFER to STEERING COLUMN article.
 
  • Steering shaft insulators damaged or worn
 
  • Intermediate/flexible shaft compressed or extended
  • INSPECT the rubber spider coupling for damage. INSTALL a new intermediate/flexible shaft. REFER to STEERING COLUMN article.
  • Steering column squeak or cracks
  • Insufficient lubricated steering shaft bushings
  • LUBRICATE the steering shaft and shaft tube seals.
 
  • Loose or misaligned steering column shrouds
  • TIGHTEN or ALIGN the steering column shrouds.
 
  • Steering wheel rubbing against steering column shrouds
  • REPOSITION the steering column shrouds.
 
  • Insufficient lubricated speed control slip ring
  • LUBRICATE the speed control slip ring.
 
  • Upper or lower bearing sleeve out of position
  • REPOSITION the bearing sleeves.
  • Power steering pump noisy
  • Incorrect assembly of components
  • Imperfections on the outside diameter or end surface of the power steering pump rotor
  • Damaged or worn power steering pump rotor splines
  • A crack on the inner surface of the power steering pump cam
  • Interference between the power steering pump rotor and cam
  • Damaged or worn power steering pump rotor and pressure plates
  • REPAIR or INSTALL a new power steering pump as necessary. REFER to POWER STEERING article.
  • Power steering pump swish noise
  • Power steering fluid flow into the bypass valve of the pump valve housing with fluid temperature below 54°C (130°F)
  • Acceptable condition.
  • Power steering pump whine noise
  • Aerated fluid
 
  • Damaged power steering pump cam
  • REPAIR or INSTALL a new power steering pump as necessary. REFER to POWER STEERING article.
 
  • Damaged valve cover O-ring seal
  • REPAIR or INSTALL a new power steering pump as necessary. REFER to POWER STEERING article.
  • Power steering pump clicking (mechanical) noise
  • Power steering pump rotor slippers too long, excessive rotor slipper-to-slot clearance or damaged or worn rotor assembly
  • REPAIR or INSTALL a new power steering pump as necessary. REFER to POWER STEERING article.
  • Power steering pump clatter noise
  • Damaged corners on the outside diameter or the power steering rotor or distorted rotor slipper ring
  • REPAIR or INSTALL a new power steering pump as necessary. REFER to POWER STEERING article.
Symptom Chart - Suspension Noise/Vibration

Condition Possible Sources Action
  • Squeak or grunt - noise from the front suspension, occurs more in cold ambient temperatures. More noticeable over rough roads or when turning
  • Front stabilizer bar insulators
  • Under these conditions, the noise is acceptable. CHECK TSBs.
  • Clunk - noise from the front suspension, occurs in and out of turns
  • Loose front struts or shocks
  • Clunk - noise from the rear suspension, occurs when shifting from REVERSE to drive
  • Loose rear suspension components
  • Click or pop - noise from the front suspension. More noticeable over rough roads or over bumps
  • Worn or damaged ball joints
  • Front suspension noise - a squeak, creak or rattle noise. Occurs mostly over bumps or rough roads
  • Steering components
  • Loose or bent front struts or shock absorbers
  • Damaged spring or spring mounts
  • Damaged or worn control/radius arm bushings
  • Worn or damaged stabilizer bar bushings or links
  • Rear suspension noise - a squeak, creak or rattle noise. Occurs mostly over bumps or rough roads
  • Loose or bent rear shock absorbers
  • Damaged spring or spring mounts
  • Damaged or worn control arm bushings
  • Worn or damaged stabilizer bar bushings or links
  • Shudder - occurs during acceleration from a slow speed or stop
  • Rear drive axle assembly mispositioned
  • CHECK the axle mounts and the rear suspension for damage or wear. REPAIR as necessary.
 
  • Incorrect or high CV joint operating angle
  • CHECK vehicle ride height is within limits. REPAIR as necessary.
 
  • Damaged or worn front suspension components
  • CHECK for a loose stabilizer bar, damaged or loose strut/strut bushings or loose or worn ball joints. INSPECT the steering linkage for wear or damage. REPAIR or INSTALL new components as necessary.
  • Shimmy - most noticeable on coast/deceleration. Also hard steering condition
  • Excessive positive caster
Symptom Chart - Tire Noise/Vibration

Condition Possible Sources Action
  • Tire noise - hum/moan at constant speeds
  • Abnormal wear patterns
  • SPIN the tire and CHECK for tire wear. INSTALL a new tire as necessary. INSPECT for damaged/worn suspension components. CARRY OUT wheel alignment.
  • Tire noise - noise tone lowers as the vehicle speed is lowered
  • Out-of-balance tire
  • BALANCE the tire and road test. INSTALL a new tire as necessary. REFER to WHEELS AND TIRES article.
  • Tire noise - ticking noise, changes with speed
  • Nail puncture or stone in tire tread
  • INSPECT the tire. REPAIR as necessary.
  • Wheel and tire - vibration and noise concern is directly related to vehicle speed and is not affected by acceleration, coasting or decelerating
  • Damaged or worn tire
  • Tire wobble or shudder - occurs at lower speeds
  • Damaged wheel bearings
 
  • Damaged wheel
  • INSPECT the wheel for damage. INSTALL a new wheel as necessary. REFER to WHEELS AND TIRES article.
 
  • Damaged or worn suspension components
  • INSPECT the suspension components for wear or damage. REPAIR as necessary.
 
  • Loose wheel nuts
  • CHECK the wheel nuts. TIGHTEN to specification. REFER to WHEELS AND TIRES article.
 
  • Damaged or uneven tire wear
  • SPIN the tire and CHECK for abnormal tire wear or damage. INSTALL a new tire as necessary. REFER to WHEELS AND TIRES article.
  • Tire shimmy or shake - occurs at lower speeds
  • Wheel/tire out of balance
  • BALANCE the wheel/tire assembly.
 
  • Uneven tire wear
  • CHECK for abnormal tire wear. INSTALL a new tire as necessary. REFER to WHEELS AND TIRES article.
 
  • Excessive radial runout of wheel or tire
  • CARRY OUT a radial runout test of the wheel and tire. INSTALL a new tire as necessary. REFER to WHEELS AND TIRES article.
 
  • Worn or damaged wheel studs or elongated stud holes
  • INSPECT the wheel studs and wheels. INSTALL new components as necessary. REFER to WHEELS AND TIRES article.
 
  • Excessive lateral runout of the wheel or tire
  • CARRY OUT a lateral runout test of the wheel and tire. CHECK the wheel, tire and hub. REPAIR or INSTALL new components as necessary.
 
  • Foreign material between the brake disc and hub or in the brake disc fins
  • CLEAN the mounting surfaces of the brake disc and hub. CHECK the brake disc fins for material.
  • High speed shake or shimmy - occurs at high speeds
  • Excessive wheel hub runout
  • Damaged or worn tires
  • Damaged or worn wheel bearings
  • Worn or damaged suspension or steering linkage components
  • Brake disc or drum imbalance
Symptom Chart - Transmission (Manual) and Transfer Case Noise/Vibration

Condition Possible Sources Action
  • Clutch rattling noise - occurs with clutch engaged, noise changes/disappears with clutch pedal depressed
  • Flywheel bolts, clutch housing bolts or clutch pressure plate bolts loose
  • TIGHTEN the bolts to specifications. CHECK the bolts for damage.
  • Clutch squeaking noise - noise is heard when the clutch is operated. Vehicle moves slowly or creeps when the clutch is disengaged. Can also be difficult to shift into FIRST and REVERSE gear
  • Pilot bearing seized or damaged
  • INSTALL a new pilot bearing.
  • Clutch squeaking noise - occurs with clutch pedal depressed/released
  • Worn clutch pedal shaft or bushings
  • INSPECT the clutch pedal for wear or damage. REPAIR as necessary.
  • Clutch whirring/rattle noise - occurs when clutch pedal is depressed
  • Worn, damaged or misaligned clutch release bearing
  • INSTALL a new clutch release bearing.
  • Clutch grating/grinding noise - occurs when clutch pedal is depressed
  • Clutch pressure plate fingers bent or worn
  • INSPECT the clutch pressure plate release fingers. INSTALL a new pressure plate as necessary.
 
  • Contact surface of clutch release bearing worn or damaged
  • INSTALL a new clutch release bearing.
  • Clutch chatter - a small amount of noise when clutch pedal is released at initial take-off
  • Clutch engagement
  • Acceptable operating condition.
  • Clutch chatter/grabs - in some cases a shudder is felt. Occurs with clutch pedal depressed/released
  • Damaged or worn powertrain/driveline mounts
  • INSPECT the powertrain/drivetrain mounts. INSTALL new mounts as necessary.
 
  • Binding or dragging plunger of the clutch master cylinder or slave cylinder
  • CHECK the master and slave cylinder operation. INSPECT the components for damage or wear. INSTALL a new master or slave cylinder as necessary.
 
  • Grease or oil on the clutch disc facing
  • CHECK the input shaft seal and rear main oil seal. REPAIR as necessary. INSTALL a new clutch disc.
 
  • Clutch disc surface glazed or damaged
  • INSPECT the clutch disc surface for a glazed, hardened or damage condition. CARRY OUT a disc check. INSTALL a new clutch disc as necessary.
 
  • Damaged or worn clutch pressure plate
  • INSPECT the clutch pressure plate for wear or damage. INSTALL a new clutch pressure plate as necessary.
 
  • Flywheel surface damaged or glazed
  • INSPECT the flywheel for damage or wear. CARRY OUT a flywheel runout check. INSTALL a new flywheel as necessary.
  • Clutch chatter noise - noise when clutch pedal is released at initial take-off. Clutch is hard to engage and disengage
  • Pilot bearing worn, damaged or not correctly aligned in bore
  • INSPECT the clutch pressure plate release fingers for uneven wear, clutch components burnt or a seized pilot bearing. INSTALL a new pilot bearing as necessary.
  • Clutch vibration
  • Loose flywheel bolts
  • Damaged or loose clutch pressure plate
  • Excessive flywheel runout
  • Transmission rattling/clattering noise - noise at idle or on light acceleration from a stop. Gear selection difficult
  • Gearshift lever joint worn or damaged
  • INSTALL a new gearshift lever.
 
  • Gearshift lever loose
  • TIGHTEN the bolts to specification.
 
  • Gearshift linkage rods worn or damaged
  • CHECK the linkage bushings for wear. INSTALL new linkage rods as necessary. REFER to the appropriate workshop manual for the service procedures.
  • Transmission rattling/clattering noise - occurs in NEUTRAL or in gear, at idle
  • Incorrect fluid level or fluid quality
  • CHECK that the transmission is filled to the correct level and with the specified fluid.
  • Transmission rattling/clattering noise - noise at idle in NEUTRAL
  • Worn or rough reverse idler gear
  • CHECK the reverse idler gear. REPAIR as necessary.
 
  • Rough running engine, cylinder misfire
  • CHECK the ignition system. CARRY OUT a cylinder power test. REPAIR as necessary.
 
  • Excessive backlash in gears
  • CHECK the gear backlash. ADJUST as necessary.
 
  • Worn countershaft gears
  • REPAIR as necessary.
  • Transmission whine - a mild whine at extreme speeds or high rpm
  • Rotating gears/geartrain
  • Acceptable noise.
  • Transmission whine - a high pitched whine, also described as a squeal
  • Transmission gears are worn (high mileage vehicle)
  • Result of normal gear wear. REPAIR as necessary.
 
  • Mismatched gear sets
  • INSPECT the gear sets for an uneven wear pattern on the face of the gear teeth. REPAIR as necessary.
 
  • Damaged or worn transmission bearing
  • INSPECT the transmission bearings. INSTALL new bearings as necessary.
  • Transmission growling/humming - noise occurs in the FORWARD gears. The noise is more prominent when the gear is loaded. The problem gear can be located as the noise occurs in a specific gear position
  • Gear is cracked, chipped or rough
  • INSPECT the transmission gears for damage or wear. INSTALL new gears as necessary.
  • Transmission hissing - noise in NEUTRAL or in FORWARD gears. As bearings wear or break up, the noise changes to a thumping noise
  • Damaged or worn bearings
  • INSPECT the transmission bearings. INSTALL new bearings as necessary.
  • Transmission knocking/thudding - noise at low speeds in FORWARD gears
  • Bearings with damaged balls or rollers or with pitted and spalled races
  • INSPECT the transmission bearings. INSTALL new bearings as necessary.
  • Transmission rumble/growl - noise at higher speeds in FORWARD gears, more pronounced in a coast/deceleration condition
  • Incorrect driveline angle
 
  • Driveshaft out of balance or damaged
  • CHECK the driveshaft for damage, missing balance weights or undercoating. Using the vibration analyzer (VA), CHECK the driveshaft balance. CARRY OUT a driveline vibration test. REFER to DRIVELINE SYSTEM - GENERAL INFORMATION article. REPAIR as necessary.
  • Transmission rumble/growl - noise at all speeds in FORWARD gears, more pronounced in a heavy acceleration condition
  • Damaged or worn transmission bearing or gears (high mileage vehicles)
  • CHECK transmission fluid for excessive metal particles. REPAIR as necessary.
  • Transfer case whine - noise at all ranges
  • Incorrect fluid level or fluid quality
 
  • Worn oil pump
 
  • Under-inflated or oversized tires
  • CONFIRM that the tires and wheels are correct for the vehicle. CHECK that the tire inflation pressures are correct.
  • Transfer case growl/rumble - noise at all ranges (A small amount of planetary noise can be heard when the transfer case is operated in low range.)
  • Damaged or worn bearings or planetary gear
  • DISASSEMBLE the transfer case. CHECK the bearings or planetary gear for wear or damage. REPAIR as necessary. REFER to FOUR WHEEL DRIVE (4WD) SYSTEMS article.
  • Transfer case scraping/grating - noise at all ranges
  • Excessively stretched drive chain hitting the case
  • Transfer case howl/hum - noise at all ranges or HIGH range only
  • Worn or damaged sun (input) gear, clutch pack (intermediate) gear or output shaft gear
  • Transfer case howl/hum - noise at LOW range only
  • Worn or damaged intermediate gear and sliding gears (clutch pack)
  • Transfer case vibration - vibration felt with vehicle in 4WD
  • Transfer case mounting
  • Driveshaft out of balance
  • Excessive pinion flange runout
Symptom Chart - Transmission (Automatic) Noise/Vibration

Condition Possible Sources Action
  • Rattle - occurs at IDLE or at light acceleration from a stop
  • Damaged engine or transmission mounts
 
  • A loose front exhaust pipe heat shield
  • REPAIR or INSTALL a new heat shield as necessary.
 
  • Loose inspection plate or dust cover plate
 
  • Loose flexplate to converter nuts
  • Whine - pitch increases with vehicle speed. Starts in FIRST and SECOND gear, decreases or goes away at higher gears
  • Damaged or worn low one-way clutch
  • Damaged or worn intermediate one-way clutch
  • Friction elements
  • Damaged or worn planetary or sun gear
  • Whine - the pitch changes with engine speed
  • A worn or damaged accessory drive component
  • CARRY OUT the Engine Accessory Test. REPAIR or INSTALL new components as necessary.
 
  • Incorrect fluid level
 
  • Partially blocked filter
 
  • Worn or damaged torque converter
 
  • Worn or damaged front pump
  • Whine - pitch changes with vehicle speed
  • Speedometer cable or gears
  • REPAIR or INSTALL new cables or gears as necessary.
  • Whine/moan type noise - pitch increases or changes with vehicle speed
  • Damaged engine or transmission mount
 
  • U-joints worn or damaged
 
  • Damaged or worn differential ring and pinion
 
  • Planetary gears nicked or chipped
  • Whistle - noise is high pitched, constant. Changes in pitch with throttle position
  • Hydraulic pressure in the main control
 
  • Incorrect band/clutch apply pressure
 
  • Worn or damaged torque converter
  • Clunk - occurs when shifting from PARK to a DRIVE or REVERSE position
  • Damaged powertrain mounts
  • INSPECT the powertrain mounts for damage. INSTALL new mounts as necessary.
 
  • Damaged or worn pinion bearings
 
  • Worn or galled driveshaft slip yoke splines
  • CLEAN and INSPECT the splines of the yoke. INSTALL a new slip yoke as necessary. REFER to DRIVESHAFT article.
 
  • Worn friction elements or excessive clutch pack end plate play
  • Bump - occurs when shifting from PARK to a DRIVE or REVERSE position. Similar to Clunk but with no sound
  • Initial gear engagement
  • Acceptable condition.
  • Buzz or hiss
  • Incorrect driveline angles
 
  • Worn or damaged main control solenoids or valves
  • Vibration - a high frequency (20-80 Hz) that is felt through the seat or gear shifter. Changes with engine speed
  • Transmission cooler lines grounded out
  • CHECK the transmission cooler lines. REPAIR as necessary.
 
  • Flexplate to torque converter nuts loose
 
  • Fluid filler tube grounded out
  • CHECK the fluid filler tube. REPAIR as necessary.
 
  • Shift cable incorrectly routed, grounded out or loose
  • Shutter or chatter - occurs with light to medium acceleration from low speeds or a stop
  • Electrical inputs/outputs
  • Vehicle wiring harness
  • Incorrect inputs/outputs from the powertrain control module (PCM), digital transmission range (TR) sensor, brake pedal position (BPP) sensor, throttle position (TP) sensor, transmission speed sensor (TSS), output speed shaft (OSS) sensor or the torque converter clutch (TCC)
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