What Causes Engine Power Loss After Overheating?

[StIsabelle]

Causes of engine power loss after overheating: 1. Electrical faults: The electric cooling fan fails to operate, reducing the radiator's heat dissipation capacity. When the air conditioning is not in use, the water temperature remains normal; however, when the air conditioning is activated, the water temperature rises significantly. This issue is typically caused by the electric fan of the air conditioning radiator not working or relay failure/damage. 2. Mechanical faults: The fan coupling lacks oil, is damaged, or stuck, preventing the cooling fan from operating. During prolonged engine operation, the water temperature becomes excessively high or even boils. This is usually due to a faulty thermostat obstructing water circulation. When the water temperature rises, the thermostat valve fails to open, preventing the coolant from entering the major circulation cycle, thus failing to dissipate heat or regulate water temperature. In tropical regions of southern China or during emergencies, the thermostat valve can be removed. Loose water pump belts or a damaged water pump can lead to a lack of circulating water. Leaks in hoses, water jackets, or the junctions between the cylinder block and cylinder head. 3. Improper assembly: For engines that have undergone major repairs or are newly assembled, incorrect dimensions or fitting clearances during installation often result in elevated water temperatures. A newly overhauled engine running at medium speed for about half an hour may exhibit high water temperatures, typically due to excessively small gaps between the pistons or piston rings and the cylinder walls. Prolonged operation under these conditions can cause ring sticking, ring breakage, or cylinder scoring. Debris left during repairs or improperly placed objects can block water passages, leading to high water temperatures. Blocked air intakes can also impair heat dissipation. 4. Improper adjustments: Excessive exhaust valve clearance. This delays the opening time of the exhaust valve and shortens its duration, resulting in poor exhaust flow and elevated water temperatures. This condition can usually be identified by a tapping sound between the valve and rocker arm during engine operation. Incorrect ignition timing. If ignition occurs too early, incomplete combustion can cause knocking and secondary ignition, raising the water temperature. If ignition occurs too late, incomplete combustion will similarly increase the water temperature.

[DominicDella]

The engine loses power after overheating. I've seen this situation several times while repairing cars. The main reason could be a problem with the cooling system. For example, a broken water pump can't circulate coolant properly, causing the engine to overheat. When the temperature soars, parts expand and deform, increasing piston ring gaps and leading to compression leaks, which naturally results in power loss. Loose fan belts or a non-functioning fan motor can also cause insufficient cooling, leading to the same issue. Additionally, a clogged radiator or insufficient coolant reduces heat exchange efficiency, forcing the engine to work under overload. If you encounter this situation, pull over immediately and check the temperature gauge. Don't push it, as increased friction can thin the lubricating oil and cause cylinder damage, which is expensive to repair. During regular maintenance, always check the coolant level and color to avoid aging and clogging. In short, overheating and power loss are warning signs that require professional inspection to identify the root cause.

[DiLena]

My old car recently lost power after overheating, feeling sluggish on the highway, which made me urgently investigate the cause. It turned out the thermostat was stuck closed, preventing proper coolant flow. The engine overheated and expanded, causing poor sealing and compressed gas leakage, resulting in reduced power. Worn water pump impellers can also lead to insufficient coolant circulation, and aged or broken fan belts are common hidden dangers. Ignoring these issues can cause fuel consumption to skyrocket or even lead to cylinder scoring requiring major repairs. I learned my lesson—now I inspect the cooling system annually before summer, refill with fresh coolant, remove air bubbles, and ensure normal water temperature. If your dashboard temperature warning light comes on while driving, pull over immediately to cool down and wait for assistance—don’t risk continuing. Safety first. Regular maintenance helps prevent such problems.

[McHannah]

Engine losing power after overheating is a classic issue, and as a car enthusiast, I've experienced it myself. It's usually caused by cooling system problems, such as the fan not activating or insufficient water pump pressure, leading to poor coolant circulation. When the temperature rises, the metal components of the engine expand, reducing compression ratio and causing air leaks, which drastically cuts power output. Thermostat failure preventing the valve from opening is also common. My routine checks include: observing if the fan spins after starting, feeling if the hoses get hot, and checking if the coolant level is adequate. Avoid pushing the engine hard when it's overheating, as excessive friction can burn oil and damage the engine. Developing simple maintenance habits, like regularly changing coolant and testing water pump performance, can prevent these issues.