What is the problem when all the coolant leaks?
3 Answers
The main issue causing complete coolant leakage is a crack in the engine block. Below are the relevant explanations: 1. Natural loss: Various fluids in a car experience natural loss. Since coolant is responsible for cooling the car engine and is often in a high-temperature state, it is normal for coolant to lose about 10%-36% per year. According to the technical requirements of NB/SH/T0521-2010 "Ethylene Glycol and Propylene Glycol Engine Coolants" issued by the National Energy Administration, the boiling point of a 50% volume fraction of coolant is above 100°C, and the loss is mainly due to natural evaporation. Without replacement, the annual loss ranges between 10%-36%. 2. Coolant entering the cylinder for combustion: For example, cracks in the engine block, cylinder head gasket burning or corrosion deformation, etc. In such cases, pulling out the dipstick to check if the engine oil shows emulsification. The engine block has oil and water channels. Once the cylinder head gasket is damaged, the water channel cannot be sealed, resulting in complete coolant leakage.
This morning, I just encountered a car towed to the shop with all its coolant leaked out. This situation is mostly caused by a complete failure of a critical component in the cooling system. Common culprits include a cracked radiator, burst hoses, or a failed water pump seal. Especially for older cars, the plastic parts of the radiator can crack from minor bumps due to aging. If the water pump fails, the leakage is particularly rapid, leaving a large puddle under the front of the car. The most troublesome issue is a blown head gasket, where coolant mixes with the engine oil, and white smoke comes out of the exhaust. If you suddenly notice the temperature gauge in the red zone, it's best to stop and check immediately—continuing to drive can cause severe engine damage. Last week, a driver insisted on driving despite the warning and ended up spending 5,000 RMB on a major engine overhaul—a painful lesson indeed.
My cousin's car ran out of coolant on the highway yesterday and ended up costing over 800 yuan to replace the hose. This kind of issue usually occurs in a few places: first, the radiator, especially if the plastic part gets hit by a stone; aging and cracked rubber hoses are also very common, especially in cars over ten years old; the water pump seal can wear out and leak from the bottom; and there's the heater core connector, located behind the dashboard, which requires dismantling the center console to repair. I remember the last time I drove my old Passat, it also leaked coolant, and the inspection revealed a crack in the thermostat housing. If you notice pink or green stains on the ground, it's best not to start the engine and call a tow truck immediately.
