GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

Inspect the flywheel ring gear for damage or unusual wear.

Step

Action

Yes

No

1

Did you review the Battery Description and Operation , Starting System Description and Operation and Charging System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Engine Electrical

2

Start the engine.

Does the starter operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Start the engine while listening to the starter motor turn.

Is there a loud whoop, (it may sound like a siren if the engine is revved while the starter is engaged), after the engine starts, but while the starter is still held in the engaged position?

Go to Step 6

Go to Step 4

4

Do you hear a rumble, a growl, or, in some cases, a knock as the starter is coasting down to a stop after starting the engine?

Go to Step 7

Go to Step 5

5

When the engine is cranked, do you hear a high-pitched whine after the engine cranks and starts normally? (This is often diagnosed as a starter drive gear hang-in or a weak solenoid).

Go to Step 9

Go to Step 7

6

Inspect the flywheel ring gear for the following:

    • Chipped gear teeth
    • Missing gear teeth
    • Milled teeth

Is the flywheel bent, or does it have damaged teeth?

Go to Step 8

Go to Step 9

7

  1. Remove the starter motor. Refer to Starter Motor Replacement .
  2. Inspect the starter motor bushings and clutch gear.

Does the clutch gear have chipped or milled teeth or worn bushings?

Go to Step 9

Go to Step 8

8

Replace the flywheel.

Did you complete the replacement?

Go to Step 10

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9

Replace the starter motor. Refer to Starter Motor Replacement .

Did you complete the replacement?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3