What color of smoke is burning coolant?

Burning coolant typically produces a sweet-smelling, bluish or grayish smoke. This occurs due to the combustion of antifreeze, which contains ethylene glycol or propylene glycol. If you see this type of smoke, it may indicate an engine issue, such as a blown head gasket or a leak in the cooling system. It's advisable to address the problem promptly to prevent further engine damage.