Accessory drive diagnostics and checks

Inspection and verification

1. Check the validity of the customer's complaint.

2. Visually inspect for obvious signs of mechanical damage.

Visual Inspection Table

Mechanical factors:

• Damaged or dirty accessory drive belt
• Incorrect accessory drive belt
• Accessory belt tensioner.
• Accessory drive belt intermediate pulley.
• Generator
• Power steering pump
• Air conditioning compressor (A/C)
• Pulley (s)
• Loose fasteners

3. If an obvious cause of the problem you identified or the customer described is found, fix it before proceeding to the next steps (if possible).

CAUTION: Do not lubricate the accessory drive belt, accessory drive belt tensioner, or idler pulley (s), because this may cause damage to the material structure of the accessory drive belt, the accessory drive belt tensioner damping mechanism, the accessory drive belt tensioner pulley bearing, and the idler pulley bearing (ov).

NOTE: Up to 15 cracks per rib at 100mm are allowed. If the cracks are out of tolerance or if any belt fragments are missing, install a new accessory drive belt.

4. The condition of the accessory drive belt should be compared with the figure and appropriate action taken.

• 1. Small scattered deposits of crumb rubber are not a problem and therefore a new accessory drive belt should not be installed.
• 2. Extended deposits of crumb rubber up to 50% of the height of the accessory drive belt rib are not a problem, but they can cause excessive noise. If there is excessive noise, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section.
• 3. Large deposits of crumb rubber along the grooves are a problem and can cause increased noise and stability of the accessory drive belt. If large deposits or excessive accessory drive belt noise are evident, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section.

5. Check the accessory drive belt for cracks. If the amount of damage exceeds the allowable limit, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section.




6. Check the accessory drive belt for damage. If large belt fragments are missing, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section.

7. Check the accessory drive belt for fraying. The condition of the accessory drive belt should be compared with the figures. For levels 1 to 3, the accessory drive belt does NOT need to be replaced. For levels 4 and 5, INSTALL a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section.

• 1. No wear (new belt)
• 2. Wear is just beginning
• 3. Light wear
• 4. High degree of wear without breaking the cord
• 5. High wear with cord breakage

8. If the cause is not visually obvious, check the symptom and refer to the Symptom Chart.

Symptom table

State	Possible Causes	Action
• Noise or squeal of accessory drive belt	• Worn or damaged accessory drive elements.	•CHECK the system with the engine running and the accessory drive belt removed (let the engine run only for a very short period). If noise is present, the cause is not the accessory drive system. If there is no noise, the accessory drive system is the cause. CHECK where the noise is coming from and INSTALL new parts if necessary. CHECK the system is working properly.
	• Incorrect installation of accessory drive elements.	• CHECK that the accessory drive components are correctly installed. REPAIR if necessary.
	• The accessory drive belt is not installed correctly.	• CHECK that the accessory drive belt is correctly installed in the pulley grooves. INSTALL a new accessory drive belt if necessary. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section. CHECK the system is working properly.
	•Pulley (s)	•CHECK pulley (s) for damage and freedom of rotation and correct alignment. INSTALL new items as needed.
	• Grease or other contamination.	• CHECK the accessory drive belt for dirt or damage. REMOVE the accessory drive belt and wash it with detergent and water. If the accessory drive belt does not clean or is damaged, INSTALL a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section. CHECK the system is working properly.
	•Accessory drive belt	• CHECK the correct use of the accessory drive belt. INSTALL a new accessory drive belt. CHECK the system is working properly. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section. CHECK the system is working properly.
• Fraying accessory drive belt	•Accessory drive belt. •Pulley (s) •Generator. •Power steering pump • A/C compressor.	•CHECK pulley (s) for damage and freedom of rotation and correct alignment. Install new elements if necessary. CHECK the system is working properly.
• Accessory drive belt does not hold tension	• The accessory drive belt is cracked or damaged.	• INSPECT the accessory drive belt for cracks or damage. If the cracks are within acceptable limits, the accessory drive belt is OK. If the cracks exceed the allowable limit, INSTALL a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L Engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles Without Accessory Drive Belt Tensioner available in this section. CHECK the system is working properly.
	• Worn or damaged accessory drive belt tensioner.	• INSPECT the accessory drive belt tensioner for proper operation or damage. INSTALL a new accessory drive belt tensioner if necessary. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt Tensioner - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt Tensioner - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt Tensioner - available in this section. CHECK the system is working properly.

Item checks

Accessory Drive Belt Tensioner - Static Check

The accessory drive belt tensioner can be checked statically by proceeding as follows:

1. Disconnect the accessory drive belt at the accessory drive belt tensioner area.

2. Using the correct tool, move the accessory belt tensioner from its free position to full piston travel and back to the free position to make sure there is no binding or sticking, and check that the accessory belt tensioner spring is in position. in a tense state.

3. Rotate the accessory drive belt tensioner pulley and check for damage and free rotation and alignment. INSTALL a new accessory drive belt tensioner if necessary.

4. Inspect the area around the accessory drive belt tensioner for grease or other contamination. Repair any leaks before installing a new accessory drive belt tensioner. If the accessory drive belt tensioner is dirty, do not attempt to clean it as the damping mechanism located inside may be damaged. INSTALL a new accessory drive belt tensioner if necessary.

5. If the accessory drive belt tensioner meets the above criteria, proceed with the accessory drive belt tensioner dynamic test. If the accessory drive belt tensioner does not meet the above criteria, INSTALL a new accessory drive belt tensioner.

Accessory Drive Belt Tensioner - Dynamic Check

The accessory drive belt tensioner can be checked dynamically by proceeding as follows:

1. With the engine running, observe the movement of the accessory drive belt tensioner. The accessory drive belt tensioner must move (to react) when accelerating the engine hard or when cycling the A/C clutch. If the movement of the accessory belt tensioner is not constant without engine acceleration or A/C clutch cycling, the pulley or shaft may be deformed or out of roundness, or the damping mechanism located inside the accessory belt tensioner may be damaged. Accessory drive belt overrun (uneven depth of grooves in the accessory drive belt) may be causing excessive movement of the accessory drive belt tensioner. Check the problem condition by installing a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt Tensioner - available in this section for more information. Vehicles with 1.6L Duratec engine. For more information refer to Accessory Drive Belt Tensioner - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. Refer to Accessory Drive Belt Tensioner - available in this section for more information. CHECK the system is working properly.