Pinpoint Test AE: Front End Noise - During Acceleration (Tip-In) Or Deceleration (Tip-Out)
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.
- AE1: FRONT END NOISE EVALUATION
- Test drive the vehicle, determine if the noise occurs only during braking or if the noise occurs during braking, acceleration and deceleration.
- Does the noise ONLY occur during vehicle braking?
Yes No REFER to BRAKE SYSTEM - GENERAL INFORMATION to diagnose the braking system. Go to AE2.
- AE2: SERVICE BAY ACTIVE UNDER HOOD FRONT END NOISE INSPECTION NOTE: Noise sources can be identified by stethoscope or hands-on during vehicle rocking. Tip-in and tip-out noises are not usually steering gear related.
- Prepare the vehicle for testing in a quiet area on level ground.
- Steer the front wheels into the straight-ahead position.
- Shift the transmission into PARK (automatic transmission) or THIRD (manual transmission).
- Shut the engine off.
- Release the parking brake.
- Open the hood.
- Rock the vehicle backwards and forwards by pushing on the front bumper and attempt to locate the source of the noise.
- Rocking the vehicle causes the engine mounts to flex, resulting in the movement of several components.
- Possible noise sources could be, but are not limited to:
- Steering column shaft slip joint
- Transmission or engine mounts
- Roll restrictor
- Subframe mounts
- Axle shafts or halfshafts
- Drive shafts
- All coolant tubes, air conditioning tubes and wiring harnesses
- Exhaust hangars and other related exhaust components
- Was the noise identified and located during this test?
Yes No REPAIR or INSTALL new components as necessary. Go to AE3.
- Prepare the vehicle for testing in a quiet area on level ground.
- AE3: VISUAL INSPECTION FOR FRONT END NOISE SOURCE
- With the transmission in NEUTRAL, position the vehicle on a hoist. Refer to Jacking And Lifting .
- Inspect the following components for a potential concern (loose, damaged, worn, broken):
- Engine mounts
- Transmission mounts
- Roll restrictors
- Exhaust heat shield (tinny rattle)
- Steering gear heat shield
- Exhaust isolators and bracket
- Steering column shaft slip joints (dry condition)
- Subframe mounts
- Engine to chassis wiring, tubes or brackets (loose or out of position)
- Halfshafts (FWD)
- Drive shafts (RWD)
- Mid-shaft bearing (if equipped)
- Are all of the listed components OK?
Yes No Components may pass a visual inspection but could still be making internal noises. Noise may only be identified during a test drive. REFER to the list of components in the pinpoint test step and, using a Chassis Ears or similar tool, pinpoint the noise source.
For additional NVH information, REFER to NOISE, VIBRATION AND HARSHNESS . REPAIR or INSTALL new components as necessary.REPAIR or INSTALL new components as necessary.