Is it harmful to wash a hot engine once?

[LeAllie]

Occasionally doing it once won't cause harm. However, frequent washing like this can lead to thermal contraction from the temperature difference, potentially shortening the engine's lifespan. Here's relevant information: Overview: The car engine is the device that provides power to the vehicle, determining its performance, fuel efficiency, stability, and environmental friendliness. Depending on the power source, car engines can be classified into diesel engines, gasoline engines, electric vehicle motors, and hybrids, among others. Others: Common gasoline and diesel engines belong to reciprocating piston internal combustion engines, capable of converting the chemical energy of fuel into mechanical energy for piston movement and outputting power. Gasoline engines have high rotational speeds, are lightweight, produce less noise, are easy to start, and have lower manufacturing costs. Diesel engines have higher compression ratios, greater thermal efficiency, and better fuel economy and emission performance compared to gasoline engines.

[LeonardoLynn]

As someone who frequently maintains my own car, I can tell you that washing a hot engine does pose risks. When the engine is running, internal metal components reach extremely high temperatures. Spraying cold water causes rapid cooling, generating thermal stress that may lead to micro-cracks in the cylinder head, engine block, or manifold. Electrical connections could also short-circuit or degrade due to temperature differentials. Hot oil residue mixing with water tends to form hard deposits that can clog cooling channels, potentially shortening engine lifespan over time. Just last week, a friend's car developed severe engine vibrations from this issue, costing over 500 yuan to repair sensors. I recommend waiting at least half an hour for cooling before using low-pressure water for cleaning, and never use high-pressure washers on hot components—safety first, otherwise the consequences outweigh the benefits.

[LaEvan]

From my mechanical experience, post-hot-engine wash issues often stem from physics: metals expand and contract at different rates. Aluminum parts cooling too quickly can warp or crack, especially in older cars. Temperature fluctuations may also cause seal failures leading to oil leaks, or allow steam to corrode circuit boards. Using wrong tools worsens it - high-pressure water can blast debris into air intakes or AC systems, clogging fans. I've found gentler methods far better: spray cleaners after engine cools, gently wipe surface stains with soft cloths, avoiding critical components. Regular cleaning matters, but wrong timing harms vehicles - patiently waiting for cooldown saves trouble.

[StAllison]

I think washing a hot engine is risky. Pouring cold water on a hot engine can cause thermal shock, and the rapid contraction of metal parts may lead to damage, such as strange noises or leaks. It's best to wait at least 10-15 minutes after parking for the temperature to drop before cleaning. Alternatively, use a damp cloth with cleaning solution to wipe the exterior, avoiding spraying water deep into the engine. This method is both safe and convenient. Don't underestimate small actions—preventing faults is the most economical approach. Keeping the engine clean ensures smooth operation, but there's no need to rush; avoid unnecessary repairs.

[DiJoseph]

As a novice car owner, the lesson I've learned is: Washing a hot engine may trigger electronic control issues, such as warning lights illuminating or engine surging, due to moisture affecting sensor functionality. When the engine is hot, water creates steam that can infiltrate spark plugs or coils, leading to starting difficulties. Prevention is simple: Wait until the engine cools completely—touch the casing to ensure it's not hot—then use low-pressure water, avoiding electrical wiring and filters. If abnormal startup occurs after washing, immediately shut off the engine for inspection. Never overlook temperature effects in daily maintenance, and cultivate safe habits.