Why does the car's water temperature rise quickly in summer?

[MadelineFitz]

There are many reasons for high water temperature in cars, mostly caused by water pipe leakage and insufficient coolant. Here is some extended information about the car's water temperature gauge: 1. Structure of the water temperature gauge: Its sensor is a thermistor-type sensor, fixed with threads on the engine's coolant passage. The thermistor determines the current flowing through the coil winding of the water temperature gauge, thereby driving the pointer to swing. 2. Introduction to the water temperature gauge: The water temperature gauge is an instrument that displays the temperature of the coolant, measured in ℃ (Celsius). In the past, tap water was used as the coolant for car engines, but now many car engine cooling systems use specialized coolant, hence it is also called the coolant temperature gauge. Some water temperature gauges use indicator lights instead, where the water temperature indicator light turning on indicates that the water temperature is too high.

[Susanna]

I remember encountering the issue of the temperature gauge soaring last summer, mainly due to problems with the cooling system. The prolonged operation of the air conditioning increased the engine load, and the radiator surface was completely clogged with willow catkins, making the fan noticeably less efficient than in previous years. A specific check revealed that the thermostat was stuck in the closed position, causing the coolant to circulate only in the small loop. Thick rust deposits had also built up in the radiator pipes, and the antifreeze, which hadn't been changed for five years, had long since lost its effectiveness. Now, before driving in hot weather, I've developed the habit of clearing debris from the grille. In heavy traffic, I immediately switch the air conditioning to recirculation mode, and if the water temperature becomes abnormal, I pull over, turn off the engine, and open the hood to assist with cooling.

[ReeseLynn]

Just helped my neighbor deal with an abnormal coolant temperature issue last week. Simply put, the heat dissipation couldn't keep up with heat generation, especially in 40°C extreme heat. Their car's water pump impeller was severely corroded, reducing coolant flow to just half of normal speed. A rodent-chewed wiring harness connector disabled the electric fan, while the space between condenser and radiator was clogged with poplar fluff like a quilt. The most critical issue was coolant diluted with tap water, lowering boiling point to 90°C causing bubbling. Recommend checking coolant level biweekly in summer, with complete replacement mandatory after three years. Park in shade when possible, and adding heat insulation mat under hood also helps.

[StBrianna]

Last time on the highway, the water temperature alarm suddenly went off, and only after emergency inspection did I find out the cause. Focus on checking three parts: the radiator inlet hose was sucked flat, obstructing circulation; the electric fan resistor was damaged, allowing only low-speed operation; and the radiator cap spring was aged, causing insufficient pressure. On hot days, the air density is low, and the cooling efficiency naturally drops by 20%. Running the air conditioning compressor at full capacity adds another 30% load to the engine. For short commutes, it's best to turn off the AC in advance to give the cooling system a breather, and shift to neutral at red lights to reduce the load. Older cars especially need to have their radiator grilles cleared of dead insects and leaves.