Hummer H2. Manual - part 1701

DRIVE BELT WHINE DIAGNOSIS 

Diagnostic Aids 

The drive belt(s) will not cause the whine. 

If the whine is intermittent, verify that it is not the accessory drive component(s) by varying their loads, making 

z

A loud screeching noise that is caused by a slipping drive belt(s) (this is unusual for a drive belt 
with multiple ribs)  

z

The squeal occurs when a heavy load is applied to the drive belt(s), such as an A/C compressor 
engagement, snapping the throttle, slipping on a seized pulley, or a faulty accessory drive 
component.  

1

Did you review the Symptoms - Engine Mechanical 
diagnostic information, and perform the necessary 
inspections?

Go to Step 2

Go to Symptoms - 

Engine 

Mechanical

2

Verify that there is a squealing noise. 
Does the engine make the squeal noise?

Go to Step 3

Go to Diagnostic 

Aids

3

1. Remove the drive belt(s). Refer to Drive Belt 

Replacement - Accessory or Drive Belt 
Replacement - Air Conditioning .  

2. Operate the engine for no longer than 30 to 

40 seconds.  

Does the squealing noise still exist?

Go to Engine Noise on 

Start-Up, but Only 

Lasting a Few Seconds

Go to Step 4

4

Inspect for a seized accessory drive component 
bearing or a faulty accessory drive component. 
Did you find and correct the condition?

Go to Step 9

Go to Step 5

5

Inspect the drive belt tensioner for proper operation. 
Refer to Drive Belt Tensioner Diagnosis . 
Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

Check for the correct length drive belt(s). 
Did you find and correct the condition?

Go to Step 9

Go to Step 7

7

Inspect for a misaligned pulley. 
Did you find and correct the condition?

Go to Step 9

Go to Step 8

8

Inspect for an incorrect size pulley. 
Did you find and correct the condition?

Go to Step 9

-

9

1. Install the drive belt(s). Refer to Drive Belt 

Replacement - Accessory or Drive Belt 
Replacement - Air Conditioning .  

2. Clear any codes.  

3. Run the engine in order to verify the repair.  

Does the squealing noise still exist?

-

System OK

 

2004 Hummer H2 

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

  

sure they are operating to their maximum capacity. An overcharged air conditioning (A/C) system, a power 
steering system restriction or the incorrect fluid, or a failing generator are suggested items to inspect. 

Test Description 

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

3: This test is to verify that the whine is being caused by the accessory drive component(s). Remove the 
drive belt(s) and operate the engine for a few seconds, this will verify if the whining noise is related to the 
accessory drive component. With the drive belt(s) removed the water pump will not operate and the 
engine may overheat. Also diagnostic trouble codes (DTCs) may set when the engine is operated with the 
drive belt(s) removed.  

4: This inspection should include checking the drive belt tensioner and the drive belt idler pulley 
bearings. The drive belt(s) may have to be installed and the accessory drive components operated 
separately by varying their loads. Refer to the suspected accessory drive component for the proper 
removal and installation procedure.  

Drive Belt Whine Diagnosis 

Step

Action

Yes

No

DEFINITION: A high pitched continuous noise that may be caused by an accessory drive component 
failed bearing.

NOTE:

Refer to Belt Dressing Notice in Cautions and Notices.

1

Did you review the Symptoms - Engine Mechanical 
diagnostic information, and perform the necessary 
inspections?

Go to Step 2

Go to Symptoms - 

Engine 

Mechanical

2

Verify that there is a whining noise. 
Does the engine make the whining noise?

Go to Step 3

Go to Diagnostic 

Aids

3

1. Remove the drive belt(s). Refer to Drive Belt 

Replacement - Accessory or Drive Belt 
Replacement - Air Conditioning .  

2. Operate the engine for no longer than 30 to 

40 seconds.  

Does the whining noise still exist?

Go to Engine Noise on 

Start-Up, but Only 

Lasting a Few Seconds

Go to Step 4

4

1. Inspect for a failed accessory drive 

component bearing.  

2. Install the drive belt(s). Refer to Drive Belt 

Replacement - Accessory or Drive Belt 
Replacement - Air Conditioning .  

Did you find and correct the condition?

Go to Step 5

-

1. Clear any codes.  

 

2004 Hummer H2 

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

  

DRIVE BELT RUMBLING DIAGNOSIS 

Diagnostic Aids 

Vibration from the engine operating may cause a body component or another part of the vehicle to make 
rumbling noise. 

The drive belt(s) may have a condition that can not be seen or felt. Sometimes replacing the drive belt(s) may be 
the only repair for the symptom. 

If after replacing the drive belt(s) and completing the diagnostic table, the rumbling is only heard with the drive 
belt(s) installed, there might be an accessory drive component failure. Varying the load on the accessory drive 
component(s) may aid in identifying which component is causing the rumbling noise. 

Test Description 

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

2: This test is to verify that the symptom is present during diagnosing. Other vehicle components may 
cause a similar symptom.  

3: This test is to verify that the drive belt(s) is causing the rumbling. Rumbling may be confused with an 
internal engine noise due to the similarity in the description. Remove only one drive belt at a time if the 
vehicle has multiple drive belts. Operate the engine for a few seconds, this will verify if the rumbling 
noise is related to the drive belt(s) or not. With the drive belt(s) removed the water pump will not operate 
and the engine may overheat. Also diagnostic trouble codes (DTCs) may set when the engine is operated 
with the drive belt(s) removed.  

4: Inspect the drive belt(s) to ensure that the drive belt(s) is not the cause of the noise. Small cracks across 
the ribs of the drive belt(s) will not cause the noise. Belt separation is identified by the plys of the belt 
separating, this may be seen at the edge of the belt or felt as a lump in the belt.  

5: Small amounts of pilling is a normal condition and acceptable. When the pilling is severe the drive belt
(s) does not have a smooth surface for proper operation.  

Drive Belt Rumbling Diagnosis 

5

2. Run the engine in order to verify the repair.  

Does the whining still exist?

-

System OK

Step

Action

Yes

No

DEFINITION: 

z

A low pitch tapping, knocking, or thumping noise heard at or just above idle.  

NOTE:

Refer to Belt Dressing Notice in Cautions and Notices.

 

2004 Hummer H2 

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

  

DRIVE BELT VIBRATION DIAGNOSIS 

Diagnostic Aids 

z

Heard once per revolution of the drive belt(s) or pulley(s).  

z

Rumbling may be caused from: 

{

Pilling, the accumulation of rubber dust that forms small balls (pills) or strings in the drive 
belt(s) pulley groove  

{

The separation of the drive belt(s)  

{

A damaged drive belt(s)  

1

Did you review the Symptoms - Engine Mechanical 
diagnostic information, and perform the necessary 
inspections?

Go to Step 2

Go to Symptoms - 

Engine 

Mechanical

2

Verify that there is a rumbling noise. 
Does the engine make the rumbling noise?

Go to Step 3

Go to Diagnostic 

Aids

3

1. Remove the drive belt(s). Refer to Drive Belt 

Replacement - Accessory or Drive Belt 
Replacement - Air Conditioning .  

2. Operate the engine for no longer than 30 to 

40 seconds.  

Does the rumbling noise still exist?

Go to Engine Noise on 

Start-Up, but Only 

Lasting a Few Seconds

Go to Step 4

4

Inspect the drive belt(s) for damage, separation, or 
sections of missing ribs. 
Were any of these conditions found?

Go to Step 7

Go to Step 5

5

Inspect for severe pilling of more than 1/3 of the 
drive belt groove depth. 
Do the drive belt grooves have pilling?

Go to Step 6

Go to Step 7

6

1. Clean the drive belt pulleys using a suitable 

wire brush.  

2. Reinstall the drive belt(s). Refer to Drive 

Belt Replacement - Accessory or Drive Belt 
Replacement - Air Conditioning .  

Did you complete the repair?

Go to Step 8

-

7

Install a new drive belt(s). Refer to Drive Belt 
Replacement - Accessory or Drive Belt 
Replacement - Air Conditioning . 
Did you complete the replacement?

Go to Step 8

-

8

1. Clear any codes.  

2. Run the engine in order to verify the repair.  

Does the rumbling noise still exist?

-

System OK

 

2004 Hummer H2 

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2