GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

    • Inspect the flywheel ring gear for damage or unusual wear.
    • Shim the starter if applicable.
    • In order to add pinion to ring gear clearance a full size shim must be used. Do not shim only 1 starter mounting bolt. There are 3 shims available in different shapes for clearance. All are 1 mm (0.039 in) thick.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

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

This is often diagnosed as a starter drive gear hang-in or a weak solenoid.

When the engine is cranked, do you hear a high-pitched whine after the engine cranks and starts normally?

Go to Step 6

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. Refer to Engine Flywheel Replacement for the 4.2 L engine, Engine Flywheel Replacement for the 5.3 L engine or Engine Flywheel Replacement for the 6.0 L engine.

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