Buick Encore Owners & Service Manuals

Buick Encore: Diagnostic information and procedures



Tire and Wheel Runout Specifications

Tire and Wheel Runout Specifications



The information contained in this Vibration Diagnosis and Correction section is designed to cover various vehicle designs and configurations. Not all content will apply to all vehicles.

NOTE: The following steps must be completed before using the analysis tables or the symptom tables.

  1. Perform the Vibration Analysis - Road Testing (EL-38792-A Electronic Vibration Analyzer), Vibration Analysis - Road Testing (CH-51450-NVH Oscilloscope) table before using the other Vibration Analysis tables or the Symptom tables in order to effectively diagnose the customer's concern.

The use of Vibration Analysis - Road Testing will first provide duplication of virtually any vibration concern and then identify the correct procedure for diagnosing the area of concern which has been duplicated.

  1. Review the following Vibration Diagnostic Process.
  2. Review the general descriptions to familiarize yourself with vibration theory and terminology, the CH- 51450-NVH Oscilloscope Diagnostic Kit (w/NVH) , or the EL-38792-A Electronic Vibration Analyzer (EVA) 2 , and the EL-38792-VS Vibrate Software. Reviewing this information will help you determine whether the condition described by the customer is a potential operating characteristic or not.

Refer to the following:

  • Vibration Theory and Terminology
  • Oscilloscope Diagnostic Kit Description and Operation
  • Electronic Vibration Analyzer (EVA) Description and Operation
  • Vibrate Software Description and Operation
  • Reed Tachometer Description

Vibration Diagnostic Process

NOTE: Using the following steps of the vibration diagnostic process will help you to effectively narrow-down and pin-point the search for the specific source of a vibration concern and to arrive at an accurate repair.

  1. Gather specific information on the customer's vibration concern.
  2. Perform the road testing steps in sequence as identified in Vibration Analysis - Road Testing in order to duplicate the customer's concern and evaluate the symptoms of the concern under changing conditions.

    Observe what the vibration feels like and what it sounds like. Observe when the symptoms first appear, when they change, and when they cease.

  3. Determine if the customer's vibration concern is truly an abnormal condition or something that is potentially an operating characteristic of the vehicle.
  4. Systematically eliminate or "rule-out" possible vehicle systems.
  5. Focus diagnostic efforts on the remaining vehicle system and systematically eliminate or "rule-out" possible components of that system.
  6. Make a repair on the remaining component, or components, which have not been eliminated systematically, and must therefore be the cause of the vibration.
  7. Verify that the customer's concern has been eliminated or at least brought to an acceptable level.
  8. Again perform the road testing steps in sequence as identified in Vibration Analysis - Road Testing in order to verify that the vehicle did not have more than one vibration occurring.

Preliminary Visual/Physical Inspection

  • Inspect for aftermarket equipment and modifications which could affect the operation of the vehicle rotating component systems.
  • Inspect the easily accessible or visible components of the vehicle rotating component systems for obvious damage or conditions which could cause the symptom.
  • Inspect the tire inflation pressures for the proper pressure.

Diagnostic Aids

Improper component routing or isolation, or components which are worn or faulty may be the cause of intermittent conditions that are difficult to duplicate. If the vibration concern could not be duplicated by following the steps of the Vibration Diagnostic Process, refer to Vibration Diagnostic Aids.


     Vibration analysis - road testing (EL-38792-A ELECTRONIC VIBRATION ANALYZER)

    Test Description The numbers below refer to the step numbers on the diagnostic table. 5 Obtaining rotational speed for the components rotating at tire/wheel speed is critical to systematically elimin

     Vibration analysis - hub and/or axle input

    Test Description The numbers below refer to the step numbers on the diagnostic table: 2 This test will determine the effect of turning input on the vibration. 6 This test will determine the effect of

     Vibration analysis - engine/accessory isolation

    Special Tools CH-51450-NVH Oscilloscope Diagnostic Kit (w/NVH) EL-38792-A Electronic Vibration Analyzer (EVA) 2 EL-38792-25 Inductive Pickup Timing Light EL-47955 Multi Diagnostic Interface MDI


     Cleaning High Gloss Surfaces and Vehicle Information and Radio Displays

    Use a microfiber cloth on high gloss surfaces or vehicle displays. First, use a soft bristle brush to remove dirt that can scratch the surface. Then gently clean by rubbing with a microfiber cloth. Never use window cleaners or solvents. Periodically hand wash the microfiber cloth separately, using

     Brake System

    Visually inspect brake lines and hoses for proper hook-up, binding, leaks, cracks, chafing, etc. Inspect disc brake pads for wear and rotors for surface condition. Inspect drum brake linings/shoes for wear or cracks. Inspect all other brake parts. Steering, Suspension, and Chassis Components Visuall

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