Road Test Quick Checks
ROAD TEST QUICK CHECKS1. 24-80 km/h (15-50 mph): With light acceleration, a moaning noise is heard and possibly a vibration is felt in the floorpan. It is usually worse at a particular engine speed and at a particular throttle setting during acceleration at that speed. It may also produce a moaning sound, depending on what component is causing it. Refer to Tip-In Moan in the symptom chart. Symptom Related Diagnostic Procedures
2. 40-72 km/h (25-45 mph): With steady to heavy acceleration or deceleration, a rumble-type noise is heard. It is very intense during heavy acceleration or deceleration and very light during cruise or neutral coast. The vibration is hard to duplicate with vehicle supported on a hoist, since the wheels are coasting free. Refer to Driveshaft Vibration in the symptom chart. Symptom Related Diagnostic Procedures
3. High Speed: With slow acceleration and deceleration or at constant speed, a shake is sometimes noticed in the steering wheel/column, seats, floorpan, trim panels or front end sheet metal. It is a low frequency vibration (around 9-15 cycles per second). It may increase when applying the brakes lightly. Refer to High-Speed Shake in the symptom chart. Symptom Related Diagnostic Procedures
4. High Speed: A vibration is felt in the floorpan or seats, with no visible shake, but with an accompanying sound or rumble, buzz, hum, drone or booming noise.
It will exist in all drive modes, but may vary somewhat in acceleration, deceleration, float or coast modes. In some cases, the driveline vibration is eliminated in the float mode. Refer to Driveshaft Vibration in the symptom chart. Symptom Related Diagnostic Procedures
5. Neutral Engine Run-Up: A vibration is felt whenever the engine reaches a particular rpm either with the vehicle in motion or while the vehicle is sitting still. It can be caused by any component from the fan back to the torque converter and by anything that turns at engine speed when the vehicle is stopped. Refer to Engine Accessory Vibration in the symptom chart. Symptom Related Diagnostic Procedures
6. Noise and Vibration While Turning: Clicking, popping or grinding noises may be due to the following:
- cut or damaged CV joint boot resulting in inadequate or contaminated lube fill in the CV joint
- loose CV joint boot clamp
- a component contacting the halfshaft assembly
- worn, damaged or improperly installed wheel bearing
- worn, contaminated or dry CV joint