What causes the engine noise to increase after a vehicle has driven through water?

[Lucian]

Common reasons for increased engine noise after a vehicle has driven through water are as follows: Increased engine noise: After a vehicle has driven through water, the most common cause of increased engine noise is water ingress into the bearings of the generator or air conditioning compressor, or rusting of the generator belt tensioner pulley bearings due to water exposure. It is essential to identify the source of the noise promptly and replace the affected components. If the noise originates from inside the engine, it is crucial to visit a repair facility as soon as possible to diagnose the issue and prevent severe engine damage. Increased transmission noise: If the vehicle has driven through water deeper than a certain level, water can enter the transmission through vents or other openings, mixing with the transmission fluid. This reduces the lubrication of components such as transmission bearings, leading to unusual noises. It is important to identify the source of the noise quickly, replace the affected parts, clean the transmission fluid passages, and replace the transmission fluid with new oil.