What are the hazards of engine temperature being too high and too low?

[McOwen]

Engine temperature being too high and too low have the following hazards respectively: Hazards of being too high: 1. It causes the mechanical properties of metal materials to gradually decrease, leading to deformation and damage; 2. The normal gaps between various components will be disrupted due to thermal expansion of parts; 3. It makes the engine oil viscosity thinner and oxidizes, reducing lubrication and accelerating part wear. Hazards of being too low: 1. It leads to reduced engine power and increased fuel consumption; 2. The viscosity of engine oil increases, causing poor lubrication and accelerating part wear; 3. It destroys the lubricating oil film, speeding up component wear.

[DeJeffrey]

During long-distance driving, I once encountered a situation where the engine was smoking due to overheating, which was quite frightening. Excessive temperature can cause severe damage, such as deformation and expansion of the engine block, seizure or burning of pistons in the cylinders, and even complete engine failure with staggering repair costs. High temperatures can also melt sealing gaskets, leading to oil leaks, reduced lubrication effectiveness, accelerated wear of components, and increased risk of engine knocking. On the other hand, if the temperature is too low, especially during cold starts in winter, the engine doesn't warm up sufficiently, resulting in incomplete combustion of gasoline, black smoke from the exhaust pipe, increased pollution, fuel wastage, and potentially a 20% rise in fuel consumption. Additionally, excessive moisture can cause rapid corrosion of piston rings, leading to carbon buildup and reduced engine power over time. Therefore, regularly checking the coolant temperature gauge is a good habit, and addressing any warning lights promptly can help prevent potential issues before they escalate.

[AylaRose]

Maintaining the engine temperature around 90 degrees is ideal. Slightly higher temperatures can cause issues: excessive metal expansion, cylinder head screw loosening leading to coolant leakage, and in severe cases, piston seizure and cylinder scoring. The engine oil thins out, losing its lubricating properties, increasing friction and causing rapid heat buildup, potentially triggering automatic system shutdown for protection. On the other hand, low temperatures are equally problematic—poor fuel atomization creates overly rich air-fuel mixtures with slow combustion, generating excessive carbon deposits, significantly reducing power output and causing emissions to exceed standards. Cold starts are most damaging to engines, as small component clearances accelerate wear. Frequent winter or short-distance driving can worsen vehicle condition—always warm up the engine for two minutes before driving.

[MacNova]

Abnormal engine temperature directly threatens safe driving. If the high-temperature warning light comes on and you don't stop to cool down in time, it may lead to breakdowns or even fire hazards. At low temperatures, the car's performance declines, acceleration becomes sluggish with increased fuel consumption, black smoke emissions cause heavy pollution, cylinder wall corrosion accelerates shortening service life, and the risk of roadside failures rises – caution is advised.