Road Test Quick Checks
Road Test Quick Checks1. 24-80km/h (15-50mph): With light acceleration, a moaning noise is heard and possibly a vibration is felt in the front floor pan. It is usually worse at a particular engine speed and at a particular throttle setting during acceleration at that speed.
Refer to the Tip-In Moan Pinpoint Test. B: Tip-In Moan
2. High Speed: With slow acceleration and deceleration, a shake is sometimes noticed in the steering wheel/column, seats, front floor pan, trim panels or front end sheet metal. It is a low frequency vibration (around 9-15 cycles per second). It may or may not be increased by applying brakes lightly.
Refer to the High Speed Shake Pinpoint Test. A: High Speed Shake
3. High Speed: A vibration is felt in the front floor pan or seats with no visible shake, but with an accompanying rumble, buzz, hum, drone, or booming noise. Coast with automatic transaxle in NEUTRAL (N) and engine idling. If vibration is still evident, it may be related to wheels, tires, front disc brake rotors, wheel hubs, or wheel bearings.
Refer to the High Speed Shake Pinpoint Test. A: High Speed Shake
4. 0-High Speed: A vibration is felt whenever the engine reaches a particular rpm. It will disappear in neutral coast. The vibration can be duplicated by operating the engine at the problem rpm while the vehicle is sitting still. It can be caused by any component, from the accessory drive belts to the torque converter, which turns at engine speed when the vehicle is stopped.
Refer to the Drive Belt Check Pinpoint Test. H: Drive Belt Check
5. Noise and Vibration While Turning. Clicking, popping, or grinding noises may be due to the following:
a. Cut or damaged front wheel driveshaft joint boot resulting in inadequate or contaminated lube fill in outboard or inboard front wheel driveshaft joint.
b. Loose front wheel driveshaft joint boot clamps.
c. Other component contacting front wheel driveshaft and joint assembly.
d. Worn, damaged or improperly installed wheel bearing.
e. Worn, contaminated, or dry inboard or outboard front wheel driveshaft joint.
6. Neutral Coast Test. A neutral coast test is a good method to determine if the engine, driveline, wheels, or tires are causing the vibration. To do this, accelerate to the legal maximum speed limit on a seldom used road, then place the gearshift lever in NEUTRAL (N) and allow the engine to return to idle speed. If the vibration exists in this condition, the investigation can be confined to the transaxle, wheels, and tires. If the vibration does not exist during neutral coast, perform an engine run-up check. G: Engine Run-Up Check