Drips under the car, and what the color can mean

A small stain or an occasional drop under a parked car may not mean much. A wet spot or a puddle deserves a closer look right away. The color of the fluid points to what's leaking, and that tells you how soon the car needs a mechanic.

What the colors mean

• Yellowish green, pastel blue or fluorescent orange. This is antifreeze. It can mean the engine has overheated, or that a hose, the water pump or the radiator is leaking.
• Dark brown or black and oily. The engine is leaking oil. A worn seal or gasket is a common cause.
• A red, oily spot. This is usually transmission fluid or power-steering fluid.
• Clear water. This is usually nothing to worry about. On a warm day it's often condensation dripping from the air conditioner.

The smells that go with a leak

A sweet, steamy smell usually means coolant is leaking. If the temperature gauge and warning light look normal, drive carefully to the nearest service station and keep an eye on the gauge. If the sweet smell comes with a hot, metallic smell and steam from under the hood, the engine has overheated. Pull over as soon as it's safe, turn the engine off and have the car towed.

A thick, sharp smell usually means oil is burning. Look under the car and around the engine for signs of a leak.

If you smell gasoline after the car won't start, the engine may be flooded. Wait a few minutes before you try again. If the smell stays, there's probably a leak in the fuel system. A fuel leak can be dangerous, so have it checked right away and don't keep driving the car.

Reading the spot

Park in your usual place overnight with a sheet of white paper or cardboard under the engine. In the morning, look at the color and whether the fluid looks oily or watery. Note whether the spot sits under the front of the car, the middle or near one wheel. Take the paper or a photo of it to the shop, since it shows the mechanic what you saw. For where to take the car, see Finding a mechanic before you need one.

An annotated example

What to do next

Check the paper after a night, then book a diagnosis for any wet spot or puddle that isn't clear water. Car maintenance basics covers the checks you can do yourself.