Leaking Fluids

What’s that stain under my car?

7 Stains that indicate car Problems

Your car runs on many more fluids than just gas. There is a wide variety of liquids that keep your car on the move, and all of them can leak. To help you make sense of any stains under your car, here is a complete, color coded list of what various liquids do and what it could mean when they’re leaking.

If you see any of these under your car, it’s time to visit your trusted car repair professional.

1. Red or pink fluid

If you see red fluid under your car, it’s most likely the transmission or power steering system. Both are extremely important to your safety, so if you see red liquid, it’s best to take your car in for an inspection. The problem could be as simple as a pinhole in a hose or a faulty transmission seal.

2. Orange fluid

An orange stain might also be transmission fluid, but it could be rust in your radiator that is tainting and staining other liquids, such as antifreeze. Either way, orange liquid leaking from your car is a red flag.

3. Yellow fluid

Yellow liquid under your car is most likely radiator coolant, possibly from a loose hose or another damaged component. It also could be that you’re using the wrong coolant: different cars use different types of coolant. Using the wrong brand of coolant in your car can lead to leaks. If you need assistance, check your owner’s manual to determine which coolant works best in your car. Or, call up HEART Certified Auto Care. We’re always happy to help.

4. Green fluid

Fluid with a greenish hue is most likely antifreeze, and it could be leaking from your radiator, water pump, or other parts of your coolant system. As mentioned above, you may be using the wrong coolant or antifreeze.

5. Blue liquid

Blue liquid under your car is most likely windshield wiper fluid. This type of leak is less urgent than some of the other issues discussed here, but definitely something you want to rectify. We suggest stopping by HEART Certified Auto Care for a free inspection.

6. Light brown liquid

This fluid is most likely motor oil or another lubricant. You can tell by its viscosity, how thick and sticky it is, and odor. If you see any grease or oil under your car, especially in large amounts, it’s definitely time to find a car repair shop near you. Leaking oil can lead to your car overheating, a breakdown, or worse. Save yourself the time, cost, and worry by having it repaired ASAP. And, while you’re at it, have an oil change, too. Because a leak can lead to contamination of all the oil in the system.

7. Clear liquid

Breathe a sigh of relief, because clear liquid coming from your car is most likely completely natural condensation from your air conditioning system. It’s nothing to worry about.

For help with leaking cars or any other auto repair, visit or call HEART Certified Auto Care. We have three convenient Chicago area locations — HEART Northbrook, HEART Wilmette, and HEART Evanston — and are happy to help in any way we can. Because we do more than repair cars; we restore your faith in the entire profession.