GM Service Manual Online
For 1990-2009 cars only

To correct starter motor noise during starting, use the following procedure:

  1. Refer to the Starter Motor Noise Diagnosis Table to determine the cause of the problem.
  2. If the diagnosis of the noise on the vehicle indicates that the pinion clearance is incorrect, make sure that the proper starter motor was installed. During initial starter motor installation, shims are not used.
  3. If diagnosis of noise indicates that the pinion clearance is incorrect, install 1.0 mm (0.04 in) full shims, one at a time, until the noise is gone. Single shims installed on the outer bolt are used to decrease clearance. Double shims installed on both bolts are used to increase clearance. Do not use more than two shims and do not exceed 2.0 mm (0.08 in).

Starter Motor Noise Diagnosis Table

Step

Action

Value

Yes

No

1

Do you hear a high pitched whine during cranking (before the engine fires) but the engine cranks and fires normally?

--

Go to Step 2

Go to Step 3

2

Reduce the distance between the starter pinion and the flywheel. Refer to step 3 in the text.

Has the noise stopped?

--

System OK

--

3

As the key is being turned, do you hear a high-pitched whine after the engine fires?

(The engine cranks and fires normally. This is often diagnosed as starter hang-in or a weak solenoid.)

--

Go to Step 4

Go to Step 5

4

Increase the distance between the starter pinion and the flywheel. Refer to step 3 in the text.

(Flywheel runout makes this appear to be intermittent.)

Has the noise stopped?

--

System OK

--

5

Is there a loud whoop after the engine fires, but while the starter is still held engaged?

(It may sound like a siren if the engine is revved while the starter is engaged.)

--

Go to Step 6

Go to Step 7

6

Remove the starter motor. Refer to Starter Motor Replacement .

Has the noise stopped?

--

System OK

--

7

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

--

Go to Step 8

System OK

8

  1. Remove the starter motor. Refer to Starter Motor Replacement .
  2. Check for a bent or unbalanced starter armature.

Has the noise stopped?

--

System OK

--