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Low coolant warning light or message on dashboard: Causes & How to Fix It

If your vehicle is showing low coolant warning light or message on dashboard, here are the most likely causes and the parts you'll need to fix each one.

Most likely causes

Leaking Coolant Hoses or Connectorsaddress soon

Rubber hoses and plastic connectors degrade over time from extreme heat cycles, causing slow or sudden coolant leaks.

Cracked or Leaking Radiatoraddress soon

The plastic end tanks on modern radiators frequently become brittle and crack with age, leading to steady coolant loss.

Water Pump Failureurgent

The water pump's internal seal can fail, causing coolant to leak from the weep hole as a warning sign of impending bearing failure.

Cracked Thermostat Housingaddress soon

Plastic thermostat housings warp and crack over time, causing a steady coolant leak near the top or side of the engine block.

Faulty Coolant Level Sensor or Cracked Reservoirminor

The sensor inside the reservoir can fail and trigger a false warning, or the plastic reservoir itself can crack and leak fluid.

Air Pocket from Improper Bleedingminor

If the cooling system was recently serviced and not properly bled, trapped air pockets will surface and drop the fluid level in the reservoir.

Blown Head Gasketurgent

A failed head gasket allows coolant to leak into the combustion chamber and burn off as white exhaust smoke, rapidly depleting coolant levels.

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