- A low-pitched tapping, detonation, or thud is only audible at idle or slightly higher.
- Heard once per revolution of the drive belt or pulley.
- Rumble may be due to the following reasons:
- 1. Build-up and incorporation of foreign particles - accumulation of rubber dust that forms small balls or threads in the groove of the drive belt pulley
- 2. Drive belt delamination
- 3. Damaged drive belt
Diagnostic Information
The rumbling sound may be caused by a body component or other part of the vehicle due to vibration from the running engine.
The drive belt may have properties that cannot be determined by visual inspection. Sometimes, to eliminate the symptom, it is enough to replace the drive belt.
If, after replacing the drive belt and following all of the troubleshooting charts, the rumble is heard only with the drive belt installed, then a failed accessory drive component may be the cause. Changing the load on a component (Oh) accessory drive can help identify which component is causing the rumbling noise.
Description of the test
The numbers below refer to the operations in the diagnostic table:
2. This test is done to check for the presence of this symptom at the time of diagnosis. Other components of the car can also cause a similar symptom.
3. This test is done to verify that the rumble is caused by the drive belt. The rumble can be confused with the internal noise of the engine due to the similarity in the description. Run the engine for a few seconds, this will help determine if the rumbling sound is related to the drive belt or not. Without a drive belt, the water pump will not work and the engine may overheat. Diagnostic Trouble Codes may also be activated (DTC), if the engine is running without a drive belt.
4. Carefully inspect the drive belt to make sure it is not causing the noise. Small cracks across the ribs of the drive belt will not cause noise. Belt delamination is determined by the flexing and twisting of the belt and can be seen along the side edges of the belt or felt as a bulge on the surface of the belt.
5. A small amount of build-up and inclusions is normal and acceptable. With a significant amount of sticking and inclusions, the drive belt no longer has the smooth surface necessary for proper functioning.
| Step | Operation | Values | Yes | No |
| 1 |
Have you read the diagnostic information Symptom - Engine Mechanical and performed the necessary inspections?
|
-
|
Go to operation 2
|
Go to item Symptoms - Engine Mechanical
|
| 2 |
Check for a rumbling sound.
Does the engine make a rattling sound?
|
-
|
Go to operation 3
|
Go to Diagnostic Information
|
| 3 |
Is the whistling sound still present?
|
-
|
Go to operation 4
|
|
| 4 |
Inspect the drive belt for damage, splitting, or missing rib sections.
Have any of these conditions been found?
|
-
|
Jump to Operation 7
|
Go to operation 5
|
| 5 |
Inspect for sticking and inclusions more than 1/3 of the depth of the drive belt groove.
Do the drive belt grooves have build-up and inclusions?
|
-
|
Go to operation 6
|
Jump to Operation 7
|
| 6 |
Repair completed?
|
-
|
Jump to operation 8
|
-
|
| 7 |
Install a new drive belt. See Section 1C1, Engine Mechanical - FAM II 2.4D.
Has the replacement been made?
|
-
|
Jump to operation 8
|
-
|
| 8 |
Is the rumbling sound still present?
|
-
|
-
|
System OK
|