Why does the engine get very hot after driving for a while?
4 Answers
The reasons why the engine gets very hot after driving for a while are as follows: 1. Severe shortage of coolant: If the coolant is not checked and replenished in time, it can easily lead to engine overheating. 2. Water pump failure: After the water pump fails, the water that conducts heat for the engine cannot circulate and renew in time. After driving for a while, the water temperature will rise rapidly, and the water temperature warning light on the dashboard will also illuminate. 3. Cooling fan failure: The cooling fan is damaged or the fan does not work due to a short circuit in the wiring, or the cooling fan rotates slowly, preventing the engine's heat from dissipating. This causes the engine temperature to rise, and you can naturally feel a significant amount of heat when opening the engine compartment.
A while ago, I encountered a situation where the engine became scalding hot during a long-distance drive, which was quite alarming at first. It turned out to be the cooling system failing to keep up, most commonly due to insufficient coolant or a clogged radiator. This is especially noticeable when climbing hills with the air conditioning on in summer, as the engine load increases and temperatures soar. Another often-overlooked detail is that in older cars, the cooling fan might get stuck or suffer from aging wiring, resulting in insufficient fan speed. In my case, I later discovered a small crack in the coolant pipe causing a leak, and after fixing it, everything returned to normal. Now, before every long trip, I make it a habit to pop the hood and check the coolant level and fan condition—this simple routine can prevent breakdowns on the road.
As someone who frequently deals with such malfunctions, I've observed that engine overheating often centers around a few key points: poor coolant circulation accounts for 70% of cases, such as a broken water pump or a stuck thermostat; radiators clogged with insects or willow catkins are also quite common; aged engine oil can lead to insufficient lubrication, increasing friction and heat generation. Just last week, I repaired a car where the issue was poor contact in the fan relay. I advise drivers to turn the heater to maximum to assist with cooling if they notice the temperature gauge spiking, and then stop the vehicle immediately for inspection. It's also important to always use the manufacturer-specified type of coolant, as mixing different brands can easily produce sediment that clogs the pipes.
Last month, white smoke coming from my car's engine compartment was an overheating warning. Let me explain the cooling principle: when the engine runs, the combustion chamber temperature reaches nearly a thousand degrees. The coolant circulates to carry away the heat, cools down through the radiator, and then flows back. If any part of this process fails—like the water pump impeller corroding and slowing the flow rate, or the radiator exterior getting clogged with mud—heat buildup happens quickly. Once, I forgot to replace the antifreeze that was three years overdue, and rust debris inside blocked the narrow pipes. Now, every 20,000 kilometers, I use a high-pressure water gun to clean the radiator gaps, and I replace the antifreeze every four years without fail. I recommend avoiding tap water as a coolant substitute—the risk of scale buildup is too high.
