Inspection and Verification

1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical damage.

   Visual Inspection Chart 

   VISUAL INSPECTION CHART
   
   

   Mechanical
   Drive belt cracking/chunking/wear Belt/pulley contamination Incorrectly routed belt Pulley misaligned or excessive pulley runout Loose or mislocated hardware Incorrectly routed power steering tubes (rubbing)

3. Eliminate all other non-belt related noises that could cause belt misdiagnosis, such as A/C compressor engagement chirp, power steering cavitations at low temperatures, variable camshaft timing (VCT) tick or generator whine.
4. If concern is found, correct the condition before proceeding to the next step.

   V-Ribbed Serpentine Belt With Cracks Across Ribs 

   Fig 1: Identifying V-Ribbed Serpentine Belt With Cracks Across Ribs

   Courtesy of MAZDA MOTORS CORP.
   NOTE:

   • Up to 15 cracks in a rib over a distance of 100 mm (3.93 in) can be considered acceptable. If damage exceeds the acceptable limit or any chunks are found to be missing from the ribs, a new belt must be installed.
5. Check the belt for cracks.

   V-Ribbed Serpentine Belt With Piling 

   NOTE:

   • Piling is an excessive buildup in the V-grooves of the belt.
   Fig 2: Identifying V-Ribbed Serpentine Belt With Piling

   Courtesy of MAZDA MOTORS CORP.
6. The condition of the drive belt should be compared against the illustration and appropriate action taken.
   1. Small scattered deposits of rubber material. This is not a concern, therefore, installation of a new belt is not required.
   2. Longer deposit areas building up to 50 percent of the rib height. This is not considered a concern but it can result in excessive noise. If noise is apparent, install a new belt.
   3. Heavy deposits building up along the grooves resulting in a possible noise and belt stability concern. If heavy deposits are apparent, install a new belt.

   V-Ribbed Serpentine Belt With Chunks of Rib Missing 

   Fig 3: Identifying V-Ribbed Serpentine Belt With Chunks Of Rib Missing

   Courtesy of MAZDA MOTORS CORP.
7. There should be no chunks missing from the belt ribs. If the belt shows any evidence of this, install a new accessory drive belt.
8. If the concern is not visually evident, verify the symptom. See SYMPTOM TROUBLESHOOTING CHART - DRIVE BELT , .

Drive Belt Noise/Flutter 

Drive belt chirp occurs due to pulley misalignment or excessive pulley runout. It can be the result of a damaged or an incorrectly aligned grooved pulley.

To correct, determine the area where the noise comes from. Check each of the pulleys in that area with a straightedge to the crankshaft pulley. Look for accessory pulleys out of position in the fore/aft direction or at an angle to the straightedge.

Drive belt squeal may be an intermittent or constant noise that occurs when the drive belt slips on an accessory pulley under certain conditions.

A short intermittent squeal may occur during engine start-up and shut down or during very rapid engine acceleration and decelerations, such as:

• wide open throttle 1 - 2 and 2 - 3 shifts or 2 - 3 and 3 - 4 back out shifts on automatic transmissions.
• wide open throttle 1 - 2 and 2 - 3 shifts and any combination of rapid downshifting on manual transmissions.

These special short-term transient events are expected, and are due to the higher system inertias required to meet the electrical and cooling demands on today's vehicle systems. Constant or re-occurring drive belt squeal can occur under these conditions:

• if the A/C discharge pressure goes above specifications:
  • the A/C system is overcharged.
  • the A/C condenser core airflow is blocked.
• if the A/C OFF equalized pressure (the common discharged and suction pressure that occurs after several minutes) exceeds specifications.
• if any of the accessories are damaged or have a worn or damaged bearing. All accessories should be rotatable by hand in the unloaded condition, if not, inspect the accessory.
• if there is evidence of fluid contamination on the accessory drive belt. When the drive belt has been exposed to fluid contamination during vehicle operation, such as leaks from the power steering system, A/C system or cooling system, clean all pulleys with soap and water, rinse with clean water and install a new accessory drive belt. If the drive belt has been exposed to fluids in a localized area during routine vehicle service, such as replacement of hoses or fluids, the drive belt and pulleys should be washed with soap and water immediately (prior to starting the engine), and rinsed with clean water.
• if the accessory drive belt is too long. A drive belt that is too long will allow the accessory drive belt tensioner arm to go all the way to the arm travel stop under certain load conditions, which will release tension to the drive belt. If the accessory drive belt tensioner indicator is outside the normal installation wear range window, install a new accessory drive belt.

• Install a new accessory drive belt tensioner if the drive belt tensioner is worn or damaged.

Incorrect Drive Belt Installation 

Non-standard accessory drive belts can track differently or incorrectly. If an accessory drive belt tracks incorrectly, install a new accessory drive belt to avoid performance failure or loss of the drive belt.

Incorrect Installation 

Fig 4: Identifying Incorrect Installation Of Drive Belt

Courtesy of MAZDA MOTORS CORP.

Correct Installation 

Fig 5: Identifying Correct Installation Of Drive Belt

Courtesy of MAZDA MOTORS CORP.

With the engine running, check accessory drive belt tracking on all pulleys. If the edge of the accessory drive belt rides beyond the edge of the pulleys, noise and premature wear will occur. Make sure the accessory drive belt rides correctly on the pulley. If an accessory drive belt tracking condition exists, proceed with the following:

• Visually check the accessory drive belt tensioner for damage, especially the mounting pad surface. If the accessory drive belt tensioner is not installed correctly, the mounting surface pad will be out of position. This will result in chirp and squeal noises.
• With the engine running, visually observe the grooves in the pulleys (not the pulley flanges or the pulley forward faces) for excessive wobble. Install new components as necessary.
• Check all accessories, mounting brackets and the accessory drive belt tensioner for any interference that would prevent the component from mounting correctly. Correct any interference condition and recheck the accessory drive belt tracking.
• Tighten all accessories, mounting brackets and accessory drive belt tensioner retaining hardware to specification. Recheck the accessory drive belt tracking.

Belt Tensioner - Mechanical 

The only mechanical check that needs to be made is a check for tensioner stick, grab or bind.

1. With the engine not running, check routing of the belt.
2. Detach the belt in the area of the tensioner.
3. Using the correct tool, move the tensioner from its relaxed position, through its full stroke and back to the relaxed position to make sure there is no stick, grab or bind, and to make sure that there is tension on the tensioner spring.
4. Rotate the tensioner pulley and check for a binding, contaminated or seized condition. Install a new tensioner if necessary. See BELT TENSIONER REMOVAL / INSTALLATION - 2.3L , .
5. Inspect the area surrounding the tensioner for oil leaks or contamination. Repair any leaks before installing a new tensioner. If the tensioner is contaminated, do not attempt to clean it as the damping mechanism inside may be damaged. Install a new tensioner if necessary. See BELT TENSIONER REMOVAL / INSTALLATION - 2.3L , .
6. If the tensioner meets the above criteria, proceed to test the tensioner dynamically. If the tensioner does not meet the above criteria, install a new tensioner. See BELT TENSIONER REMOVAL / INSTALLATION - 2.3L , .

   Belt Tensioner - Dynamic 

   The automatic belt tensioner can be checked dynamically as follows:

7. With the engine running, observe the belt tensioner movement. The tensioner should move (respond) when the air conditioning clutch cycles (if equipped), or when the engine is accelerated rapidly. If the tensioner movement is excessive without air conditioning clutch cycling or engine acceleration, a pulley or shaft is possibly bent, or out of round or the damper mechanism inside the tensioner may be damaged. Excessive belt rideout (uneven depth of grooves in the belt) can cause excessive tensioner movement. Check condition by installing a new belt. See DRIVE BELT REMOVAL / INSTALLATION - 2.3L , .