Sweet Smell in Cabin: A Dangerous Coolant Leak Warning

You turn on the air conditioning or the heater. A strange, sweet smell fills the cabin. It is almost pleasant at first—like maple syrup or artificial candy. You might ignore it. You might think it is a new air freshener or something from outside.

That smell is not a mystery. It is a warning. And if you ignore it, you are putting your engine, your wallet, and your health at risk.

The sweet smell coming from your vents is almost certainly coolant (antifreeze) leaking from your heater core. And a leaking heater core is one of the most expensive and dangerous problems your car can develop. Here is why that sweet smell is a disaster waiting to happen.