Put a piece of white cardboard under the car overnight. In the morning, the color and location of the spot will tell you a lot.
Leak color guide
| Color and feel | Likely fluid | Where it usually shows up | How urgent |
|---|---|---|---|
| Light brown to black, slick | Engine oil | Under the engine, toward the front | Keep it topped up, get it checked |
| Green, orange or pink, sweet smell | Coolant (antifreeze) | Front of the car, near the radiator | Check soon. Low coolant can overheat the engine |
| Red or reddish brown | Transmission fluid, or power steering on some cars | Middle or front of the car | Get it checked soon |
| Clear to light brown, slippery | Brake fluid | Near a wheel or under the master cylinder | Urgent. Don’t drive until it’s checked |
| Blue | Washer fluid | Front corner | Not urgent |
| Clear, like water, no smell | AC condensation | Under the passenger side front | Normal in summer |
Oil leaks are the most common
On older cars, one of the most common oil leaks is the valve cover gasket. It sits on top of the engine and gets hard with heat and age. Oil that seeps out can drip onto the exhaust, which is where that burning oil smell after a drive often comes from.
Other common spots:
- Oil filter or drain plug, especially right after an oil change
- Oil pan gasket
- Front and rear main seals
Some of these are quick driveway fixes. Some, like a rear main seal, need a lift.
Coolant leaks deserve attention
Coolant smells sweet and is toxic to pets, so clean up spots quickly. A coolant leak can come from a hose, the radiator, the water pump or the overflow tank. Running low can overheat the engine.
When to stop driving
- Brake fluid leak or a soft brake pedal
- Big puddle of coolant and the temperature gauge climbing
- Oil pressure warning light
Find it and fix it
We trace leaks to the source before quoting, then fix common ones like valve cover gaskets right in your driveway. See oil leaks and gaskets. If the spot is near a wheel, read up on brakes.