Chevrolet Silverado / GMC Sierra. Service manual — part 240

DRIVE BELT TENSIONER DIAGNOSIS

Inspection Procedure

2. Replace improper or missing fasteners.

Does the drive belt continue to fall off?

Go to Step 9

System OK

9

Test the drive belt tensioner for operating

correctly. Refer to Drive Belt Tensioner

Diagnosis.

Does the drive belt tensioner operate correctly? Go to Step 11

Go to Step 10

10

Replace the drive belt tensioner. Refer to Drive

Belt Tensioner Replacement - Accessory or

Drive Belt Tensioner Replacement - Air

Conditioning.

Does the drive belt continue to fall off?

Go to Step 11

System OK

11

Inspect for failed drive belt idler and drive belt

tensioner pulley bearings.

Did you find and repair the condition?

Go to Step 12

Go to Diagnostic
Aids

12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

13

Inspect the drive belt for the proper installation.

Refer to Drive Belt Replacement - Accessory

or Air Conditioning Compressor Belt

Replacement.

Did you find this condition?

Go to Step 16

Go to Step 14

14

Inspect for the proper drive belt.

Did you find this condition?

Go to Step 16

Go to Step 15

15

Inspect for the drive belt rubbing against a

bracket, hose, or wiring harness.

Did you find and repair the condition?

Go to Step 17

Go to Diagnostic
Aids

16

Replace the drive belt. Refer to Drive Belt

Replacement - Accessory or Air

Conditioning Compressor Belt

Replacement.

Did you complete the replacement?

Go to Step 17

-

17

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

-

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 19: Releasing Drive Belt Tension
Courtesy of GENERAL MOTORS CORP.

NOTE:

Allowing the drive belt tensioner to snap into the free position
may result in damage to the tensioner.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

1. Remove the drive belt. Refer to Drive Belt Replacement - Accessory or Air

Conditioning Compressor Belt Replacement.

2. Move the drive belt tensioner through its full travel.

The movement should feel smooth.

There should be no binding.

The tensioner should return freely.

3. If any binding is observed, replace the drive belt tensioner. Refer to Drive Belt Tensioner

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

4. Install the drive belt. Refer to of Drive Belt Replacement - Accessory or Air

Conditioning Compressor Belt Replacement.

REPAIR INSTRUCTIONS - ON VEHICLE

DRIVE BELT REPLACEMENT - ACCESSORY

Removal Procedure

IMPORTANT: When the engine is operating the drive belt tensioner arm

will move. Do not replace the drive belt tensioner because of
movement in the drive belt tensioner arm.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 20: MAF/IAT Sensor & Air Cleaner Assembly
Courtesy of GENERAL MOTORS CORP.

1. Loosen the air cleaner outlet duct clamps at the following locations:

Throttle body

Mass airflow/intake air temperature (MAF/IAT) sensor

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2