Suspension Vibrations Could Have Your Customers Singing The Blues

The song "Good Vibrations" by the Beach Boys may have been a big hit in its day, but there's no such thing as good vibrations or noise when it comes to a customer's vehicle. Vibrations are annoying and may be a warning signal that something's amiss. Any unusual noises or vibrations should be immediately investigated to determine their cause.

Most vibrations and noises can be classified according to when they occur:

Engine speed sensitive - The vibration/noise is directly related to engine speed and nothing else (not vehicle speed or driving conditions). The symptom appears or changes in direct proportion to engine rpm.
Vehicle speed sensitive - The vibration/noise occurs only at certain speeds or changes in direct proportion to vehicle speed.
Acceleration/deceleration sensitive - The vibration/noise is noticed only when vehicle speed changes (as when starting from a stop, passing, slowing down or coasting).
Random - The vibration/noise comes and goes with no obvious connection to engine rpm, vehicle speed or driving conditions.

When a customer comes to you with a vibration or noise complaint, the first diagnostic step is to get as accurate a description as possible of what's happening from your customer.

Focus on the driving conditions that accompany the vibration or sound. Does it occur only under certain driving conditions...