Is Your Car Leaking Coolant?

You may also notice the engine overheating or feel a rough idle.

The bearings and seals inside the vehicle's water pump degrade with use. If coolant isn't maintained, it becomes acidic with age, speeding up the wearing process on these seals. In addition, when the seal between the pump and coolant leaks, it creates a weep hole that lets any coolant out before it affects the pump's bearings. This causes the leak to run down the engine block, which can be seen as a crusty, discolored buildup of dried coolant. Depending on the tank's coolant type, it may be red or green.

You may also notice that the engine cranks long before starting. After the engine runs, you might see a small puddle of coolant under the car.

Coolant passages between the head gaskets connect an engine's combustion chamber to the valve chamber. These passages dissipate heat from the engine block and the heads. Engine overheating or acidic coolant can damage the head gasket. When these gaskets are compromised, gasses from combustion get into the coolant passages, causing the coolant to become superheated. Superheated coolant leads to the engine overheating and further wear on the gaskets. Coolant leaks into the engine's combustion chamber when the gaskets are badly damaged, which you'll notice as white smoke in the exhaust. That's the coolant burning with the vehicle's fuel.

You may also notice that the windows stay fogged even when the defroster is on or that the carpet on the front passenger side floor is wet.

Inside the air box in your vehicle's dash is the heater core. This circulates coolant so that your heater warms up the vehicle's interior. If the cooling system isn't maintained, the coolant turns acidic and can degrade the heater core. This can cause coolant to leak inside the vehicle. In addition, if coolant gets in the air box, it gets vaporized by air blowing over it and through your vents. You will notice this vaporized coolant as a sweet smell blowing through your heating and air conditioning vents.

You may also notice steam coming from under the hood or your engine is overheating.

The coolant reservoir is the highest point of the cooling system and is filled with half air and half liquid coolant. When a leak in the reservoir occurs, the coolant won't be low in the tank until several heat and cool cycles force enough out. It is at this point that the low coolant is visible.

You may also notice the "check engine" light is on or the "coolant temperature" gauge is running in the red.

The coolant hoses attach the engine cooling system to the radiator. Since they are made of rubber, they will become brittle over time and can crack, causing a leak. Flex from worn motor mounts can stretch the hoses as well. A band clamp attaches the hoses to the radiator or engine block. Wear over time and from temperature changes causes leaks. These leaks are most common after the vehicle cools when various components contract due to the temperature change. When your car is parked, it's cooling, and you will see the leak as evidence of this wear.