GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2001 🢒 Firebird 🢒 Engine 🢒 Engine Mechanical - 3.8L 🢒 Drive Belt Chirping Diagnosis

Diagnostic Aids

The symptom may be intermittent due to moisture on the drive belt or the pulleys. It may be necessary to spray a small amount of water on the drive belt in order to duplicate the customers concern. If spraying water on the drive belt duplicates the symptom, cleaning the belt pulleys may be the probable solution.

A loose or improper installation of a body component, a suspension component, or other item(s) on the vehicle may cause the chirping noise.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. The noise may not be engine related. This step verifies that the engine is making the noise. If the engine is not making the noise do not proceed further with this table.

    2.

  2. The noise may be an internal engine noise. Remove the drive belt and operate the engine for a brief period, verifing that the chirping noise is related to the drive belt. With the drive belt(s) removed the water pump may not operate and the engine may overheat. DTCs may set when the engine is operated with the drive belt removed.

    3.

  3. Inspect all drive belt pulleys for pilling. Pilling is the small balls or pills in the drive belt grooves from the accumulation of rubber dust.

    4.

  4. Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley may be bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across 2 or 3 pulleys. If a misaligned pulley is found, refer to that accessory drive component for the proper installation procedure for that pulley.

    5.

  5. Inspection of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed.

    6.

  6. Inspecting the pulleys for being bent should include inspecting for dents or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.

    7.

  7. Replacing the drive belt when it is not damaged or there is not excessive pilling will only be a temporary repair.

Step

Action

Yes

No

Notice: Do not use belt dressing on the drive belt. Belt dressing causes the breakdown of the composition of the drive belt. Failure to follow this recommendation will damage the drive belt.

DEFINITION: The following items are indications of chirping:

    • A high pitched noise that is heard once per revolution of the drive belt or a pulley.
    • Chirping may occur on cold damp startup conditions and will subside once the vehicle reaches normal operating temperature.

1

Did you review the Symptoms - Drive Belt diagnostic information and perform the necessary inspections?

Go to Step  2

Go to Symptoms - Engine Mechanical

2

Verify that there is a chirping noise.

Does the engine make the chirping noise?

Go to Step 3

Go to Diagnostic Aids

3

  1. Remove the drive belt.
  2. Operate the engine for no longer than 30 to 40 seconds.

Does the chirping noise still exist?

Go to Engine Noise on Start-Up, but Only Lasting a Few Seconds or Upper Engine Noise, Regardless of Engine Speed or Lower Engine Noise, Regardless of Engine Speed

Go to Step 4

4

Inspect for severe belt pilling exceeding 1/3 of the belt groove depth.

Does the belt grooves have pilling?

Go to Step 5

Go to Step 6

5

Clean the drive belt pulleys with a suitable wire brush.

Were the drive belt pulleys cleaned?

Go to Step 15

Go to Step 6

6

Inspect for a misalignment of the pulleys.

Are any of the pulleys misaligned?

Go to Step 7

Go to Step 8

7

Replace and/or repair any misaligned pulleys.

Were the misaligned pulleys repaired and/or replaced?

Go to Step 15

Go to Step 8

8

Inspect for bent and/or cracked brackets.

Were there any bent and/or cracked brackets?

Go to Step 9

Go to Step 10

9

Replace any bent and/or cracked brackets. Refer to Drive Belt Tensioner Replacement .

Were the bent and/or cracked brackets replaced?

Go to Step 15

Go to Step 10

10

Inspect for improper, missing and/or loose fasteners.

Were there any improper, missing and/or loose fasteners?

Go to Step 11

Go to Step 12

11
  1. Replace any improper and/or missing fasteners.
  2. Tighten any loose fasteners. Refer to Fastener Tightening Specifications .

Did you complete the repair?

Go to Step 15

Go to Step 12

12

Inspect for a bent pulley.

Was a bent pulley found?

Go to Step 13

Go to Step 14

13

Replace the bent pulley.

Was the bent pulley replaced?

Go to Step 15

Go to Step 14

14

Replace the drive belt. Refer to Drive Belt Replacement .

Was the drive belt replaced?

Go to Step 15

Go to Diagnostic Aids

15

Run the engine in order to verify the repair.

Does the drive belt still chirp?

Go to Step 3

System OK