Pinpoint Tests L: Front End Noise - Driving Straight On Smooth Roads
- L1: CHECK TIRE CONDITION
- Check tires for wear, damage, uneven tread or miss-matched tires (miss-matched tires are especially important on AWD and 4x4 systems).
- Verify all 4 tires are matching size and brand.
- Are the tires free from wear, damage, uneven tread or miss-matching issues?
Yes No Go to L2. INSTALL new tires as necessary. REFER to Wheels And Tires .
- L2: CHECK FOR NOISE CHANGE DURING BUMPS AND VARYING SPEEDS
- Test drive the vehicle and confirm the noise.
- Make sure to drive over bumps and vary the vehicle speed during the test.
- Was the noise affected by bumps?
Yes No Go to PINPOINT TEST AC . If the noise was affected by vehicle speed, Go to L3.
- Test drive the vehicle and confirm the noise.
- L3: VISUAL INSPECTION FOR NOISE SOURCE
- The following components can cause noise issues while rotating. Inspect the following components for looseness, wear and damage:
- Wheel hubs and bearings
- Axle shafts or halfshafts (includes center support bearing)
- Drive shafts and pinion bearings
- Left and right inner CV joints
- PTO output shaft (FWD only)
- Transfer case assembly (if equipped)
- Integrated wheel ends and associated vacuum system (4x4 only)
- Drive shaft center support bearing (RWD only)
- The following components can cause noise issues while being disturbed by the wind. Inspect the following undercarriage components for looseness, wear, witness marks or damage:
- Heat shields
- Wiring harnesses
- Tubes and hoses
- Wheel well linings and splash shields
- Air dams
- Radiator ducts or shields
- Other components not retained
- Are all of the listed components OK?
Yes No Go to L4. REPAIR or INSTALL new components as necessary.
- The following components can cause noise issues while rotating. Inspect the following components for looseness, wear and damage:
- L4: VEHICLE ON-HOIST INSPECTION
- With the transmission in NEUTRAL, position the vehicle on a hoist. Refer to Jacking And Lifting .
- Raise the vehicle until the wheels can spin freely.
- Start the engine.
- For hybrid vehicles, make sure the engine ready to run indicator is illuminated.
- Disable the AdvanceTrac or traction control system (if equipped).
- Bring the vehicle up to speed where the reported noise can be heard.
- Listen for the noise.
- Was the noise able to be replicated with the vehicle on the hoist?
Yes No Using a listening device, such as Chassis Ears, LOCATE the causal component. REPAIR or INSTALL new as necessary. Go to L5.
- L5: ROAD TEST NOISE VERIFICATION
- Using a listening device, such as Chassis Ears:
- Attach probe 1 to the back side of the left front wheel knuckle or spindle.
- Attach probe 2 to the back side of the right front wheel knuckle or spindle.
- Using an assistant to test drive the vehicle, attempt to duplicate the noise while listening to the device.
- Is the reported noise also heard through probe 1 or 2?
Yes No The noise may be caused by the wheel bearing or related components. INSPECT and REPAIR or INSTALL new as necessary (brake components, integrated wheel ends, etc.). REFER to the list of possible sources in step L3 for further evaluation of noise sources, or REFER to Noise, Vibration And Harshness to continue NVH diagnostics.
- Using a listening device, such as Chassis Ears: