Car Serpentine belt

How to detect the poly-V-belt malfunction

The condition of the belts should be checked after every 10-15 thousand km of mileage, together with every oil replacement. First, inspect the component. If it is significantly damaged, install a new one. In case of few small cracks, replacement of the component is not required. However, if cracks are less than 10-20 mm apart from each other, the belt is severely deteriorated. Also, check whether the pulleys are not fouled with dirt and foreign objects.

You may notice that the poly-V-belt requires diagnostics by the following symptoms:

• noise and whistling are heard from the component when driving;
• the belt slips, vibrates, or gets twisted;
• the reverse side of the component looks shiny and glossy;
• the engine gets overheated;
• elements of ribs are absent;
• smudges and grease marks are visible on the surface of the component;
• grooves in the ribs are clogged;
• edges of the belt are damaged;
• the battery does not hold charge;
• the base layer of the belt is damaged or torn;
• fibers on the surface of the belt are cracked.

The reasons of poly-V-belt malfunction

The poly-V-belt is subjected to heavy loads. Partly premature wear of the component is caused by high temperature in the engine compartment, as well as continuous movement. These factors are the reasons for appearance of cracks on the component and for detachment of rubber fragments.

The degree of belt tension is a critical factor. Insufficient tension may cause severe vibration and abrasion of the component, excessive tension may cause rupture. Incorrect installation of the component, in particular, its location outside the pulley, results in detachment of the ribs from the base. Belt damage may also result from its installation on worn or misaligned pulleys. Besides, the reason of breakage of base cord threads and of the belt itself may be ingress of foreign objects in the pulley.

Replacing the poly-V-belt

The maximum service life of the component is 4 years. After that period, a new component is to be installed. A damaged component is not subject to repair. Before removing the belt, remove the top of the air filter and the mass airflow sensor. Then remove the solenoid valve, and remove the bottom of the air filter. To remove the belt, loosen the tensioner. During the installation of a new component, place it in the middle of the pulleys, and unscrew the tensioner screw. At the end, install all components in the reverse order.