A car making a whining noise indicates that one or more of the belts in the engine is loose. A belt also runs the risk of slipping or not being seated properly. Belt problems are linked to a number of different parts of the engine itself.
Whining noises are associated with belt problems throughout the engine. The variety of belts in an engine compartment makes it difficult to tell which one is whining without visual inspection. Turning the car on and lifting the hood shows how the belts are running and is a good indication of which belt needs to be shifted, adjusted or replaced.
The most likely belts that cause whining in an engine are the cam shaft belt, fan belt, timing belt or tensioner. These belts hold the engine together and keep the entire car running properly, so the loss of one greatly harms the function of the rest of the machine.
Visually inspecting belts shows whether they are running properly over the gears where they are set. When these two elements are not properly aligned, the belt sliding off the wheel or causing unintended friction creates a whining sound. This also wears down the belt prematurely and results in the potential for the belt to snap while driving.