Road Test Quick Checks
Road Test Quick Checks1. 24-80 kph (15-50 mph): 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. It may also produce a moaning sound, depending on what component is causing it. Refer to Tip-in Moan Pinpoint Test B.
2. High Speed: With slow acceleration and deceleration, a shake is sometimes noticed in the steering wheel/column, seats, front floor pan, front door 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 High Speed Shake Pinpoint Test A.
3. High Speed: A vibration is felt in the front floor pan or seats with no visible shake, but with an accompanying sound or rumble, buzz, hum, drone or booming noise. Coast with clutch pedal depressed or shift control selector lever 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 front wheel bearings. Refer to the High Speed Shake Pinpoint Test A.
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 belt to the clutch or torque converter which turns at engine speed when the vehicle is stopped. Refer to Drive Belt Check Pinpoint Test H.
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 tube fill in outboard front wheel drive shaft joint or inboard front wheel drive shaft joint
b. Loose front wheel driveshaft joint boot clamp
c. Other components contacting the front wheel driveshaft and joint
d. Worn, damaged or improperly installed front wheel bearing
e. Worn, contaminated, or dry inboard front wheel driveshaft joint or outboard front wheel driveshaft joint
6. Neutral Coast Test: This 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 transaxle 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 the Engine Run-Up Check Pinpoint Test G.