The Serpentine Belt
The greatest danger, however, lies in the moving parts. If an animal—whether a cat or a marten—is sleeping near the serpentine belt or the timing belt, the consequences when the engine is started are catastrophic. The belt can catch the animal, which is fatal not only for the animal but also for the engine.
There are countless cases in which the remains of an animal caused the serpentine belt to slip off its pulleys. In the worst cases, fragments of the belt can end up behind the timing belt cover. If the timing belt jumps or snaps as a result, the valves collide with the pistons. The result is an engine destroyed from the inside. Repair costs for an overhaul or replacement engine range from three thousand to ten thousand euros.