Modern crankshaft position sensors measure more than the position of the crankshaft.
Misalignment and bearing wear can cause the belt to track off-center.
One of the noisiest components under the hood of a vehicle can be the belt and the drive components. Noise is not the fault of the belt, but the result of how the power comes from the crankshaft and the components attached to the belt.
The serpentine belt is part of a system and is not the only component susceptible to wear. The tensioner, idler pulley and, on some vehicles, the decoupler pulley all wear over time and need periodic inspection and replacement. If you are replacing just the belt without looking at the other components, you could be sending a new belt to a premature death.
Selling a replacement serpentine belt at 90,000 or 100,000 miles is easy. But, making that new belt go the same distance as the original can be more difficult. With zero miles on an odometer, the belt is operating in the best possible environment. The plane of the belt pulleys is properly aligned and there are no leaks. And, the tensioner is new and the spring and dampening elements are not worn out.
Andrew Markel talks stretch belts, and how they manage to keep working without a tensioner. Sponsored by Dayco.
Andrew Markel goes over tips to visually inspect a belt tensioner, including how to tell if the belt is running uneven. Sponsored by Litens.
Andrew Markel offers quick tips to ensure a belt tensioner replacement and installation job goes smoothly without causing any damage. Sponsored by Litens.
If an engineer could design a belt system that would never slip it would be a miracle. This perfect belt system would last a long time because without slipping, there would be very little wear. But, it is not that simple. Too much tension would increase the loads on the engine and the strain on a belt is not constant. It is a balancing act between drag, slippage and belt wear.
Most late-model engines have serpentine belt drives for the engine-driven accessories. And, most people know that belts are a maintenance item and eventually have to be replaced. However, many don’t know the spring-loaded automatic tensioner that keeps a serpentine belt tight is also a wear item. Consequently, the automatic tensioner may also have to be replaced when the time comes to change the belt.