Symptom Chart NVH

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

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 AND HARSHNESS . Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system.

Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Noise, Vibration and Harshness (NVH) .

Symptom	Possible Sources	Action
Grinding noise during 4WD system engagement, especially at high speeds	Front halfshaft speeds not turning at the same speed Sticking IWEs Sticking or leaking IWE solenoid	GO to Pinpoint Test E
The front axle makes noise in 2H mode only	Vacuum leaks Vacuum check valve Vacuum reservoir IWE solenoid IWE s Needle bearings between half shaft and wheel hub	GO to Pinpoint Test E
Grinding / clicking / ratcheting noise from front axle in 2H mode under acceleration or heavy loads	Vacuum leaks Vacuum check valve	GO to Pinpoint Test E
The transfer case makes noise	Tire inflation pressure Tire and wheel size Tire tread wear Internal components Fluid level	VERIFY all tires inflation pressures are correct. VERIFY all tires and wheels are the same. CHECK tire tread wear to see if there is more than 1.6 mm (0.062 in) or 2/32 inch difference in tread wear between front and rear. INTERCHANGE one front wheel and one rear wheel. ROAD TEST again. CHECK the transfer case shaft bearings, the upper and lower drive sprockets and drive chain for damage. INSTALL new parts as necessary CHECK that the transfer case is filled to the correct level and with the specified fluid. REFER to: Transfer Case Draining and Filling .
Transfer case whine - noise at all ranges	Incorrect fluid level or fluid quality Worn oil pump Under-inflated or oversized tires	CHECK that the transfer case is filled to the correct level and with the specified fluid. REFER to: Transfer Case Draining and Filling . DISASSEMBLE the transfer case. CHECK the oil pump for wear or damage. REPAIR as necessary. REFER to: Transfer Case - Vehicles With: 1-Speed Torque On Demand Transfer Case . 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	Damaged or worn bearings	DISASSEMBLE the transfer case. CHECK the bearings for wear or damage. REPAIR as necessary. REFER to: Transfer Case - Vehicles With: 1-Speed Torque On Demand Transfer Case .
Transfer case scraping/grating - noise at all ranges	Excessively stretched drive chain hitting the case	DISASSEMBLE the transfer case. CHECK the drive chain for wear or damage. REPAIR as necessary. REFER to: Transfer Case - Vehicles With: 1-Speed Torque On Demand Transfer Case .
The front axle makes noise in 2H mode only and generally under heavy throttle	Vacuum leaks Vacuum check valve Vacuum reservoir IWE solenoid IWE s	GO to Pinpoint Test L