Repair Guide: Steps in Identifying Timing Belt Idler Pulley Failure
Your vehicle is designed to run smoothly and silently. If you start hearing unusual noises, this usually means there might be a problem. The timing belt assembly is among the most common sources of engine noise. Since most timing belts are made from rubber, they are usually the first ones to go due to everyday wear and tear. But, the belts are not the only one that could fail in the assembly. You should also check the timing belt idler and idler pulley. The idler and idler pulley are important in keeping the timing belt properly adjusted. The timing belt idler pulley is the one located between the crank shaft gear and intake cam gear. Read below on how to identify when the idler pulley is bad or has failed.
What you'll need:
- Lug wrench
- Pulley puller
- Floor jack and jack stands
- Socket wrench
- Torque wrench
- Repair manual
- Drop light
- Drain pan
Step 1: First, secure the vehicle to the ground using a floor jack, wheel blocks, and jack stands. Make sure to consult your owner's manual to know the proper support points for your vehicle to avoid any accident. Pop the hood and secure it.
Step 2: Next, disconnect the battery. You need to remove this so you can have more room to work on when inspecting the timing belt components. Make sure to always remove the negative connection first to avoid possibility of short circuits. Remove the positive and take out the battery. Make sure to store it in a secure area.
Step 3: If you need to remove other components in the engine bay, make sure to drain the coolant in the radiator first. Use a drain pan. If you need to replace the coolant, make sure to follow proper chemical waste disposal procedures.
Step 4: Remove the timing belt cover and inspect the timing belt. Use a drop light to properly see within the engine bay. If you notice any misalignment in the timing belt, this indicates that the tensioner or idler is not correctly attached to the mounting location on the engine. This could also be due to worn idler or idler pulley as a result of excess play. Pulley alignment can be checked by placing a straight edge against it or with a special laser alignment tool designed for this purpose.
Step 5: Check the idler pulley for side-to-side play or rocking. All pulleys should turn freely without any binding, roughness, or wobble. If there is any sign of movement, it is necessary to replace the idler pulley.
Step 6: It is also necessary to check both the idler pulley and tensioner pulley for roughness when rotating the bearing. These two should spin freely and smoothly. If there is roughness detected, the bearings should be replaced.
Step 7: If there's any misalignment or sign of excessive wear in the timing belt, tensioner, and idler pulley, replace them with new components to avoid engine damage or failure. Make sure to correct any misalignment in the system before installing the new timing belt to avoid repeat problems.