Here's what you should do:
1. Pull over immediately and safely to the side of the road. Turn off the engine. Continuing to drive could cause irreparable harm.
2. Let the engine cool completely. This is crucial to avoid burns. It could take an hour or more.
3. Inspect for visible leaks. Once cool, carefully check under the car for any puddles of coolant (it's usually bright green, orange, pink, or yellow). Look around the radiator, hoses, water pump, and engine block for signs of leakage.
4. Check the coolant level. Once the engine is cool enough to touch safely, open the coolant reservoir (carefully – it may be pressurized). Check the level. Low coolant is expected if there's a leak. Never open the radiator cap while the engine is hot.
5. Call for roadside assistance or a tow truck. Attempting to drive the car with a coolant leak could severely damage the engine.
6. Have the car professionally repaired. A mechanic will need to diagnose and repair the leak. Possible causes include:
* A hole in a hose: This is a relatively inexpensive fix.
* A cracked radiator: This might require radiator repair or replacement.
* A leaking water pump: This needs replacement.
* A blown head gasket: This is a much more serious and expensive repair.
* Cracked engine block: This is a very serious and expensive problem, possibly requiring engine replacement.
The smell of burning coolant can sometimes be confused with the smell of burning antifreeze, which often has a sweet odor. Burning antifreeze is still serious and indicates a leak somewhere in the system. Either way, immediate action is necessary.
