How to Identify Automotive Fluid Leaks Based on Color

How to Identify Automotive Fluid Leaks Based on Color

6th May 2021

Have you noticed one or more puddles of fluid underneath your vehicle? Assuming it hasn't rained recently, it's probably a sign of a leak. Cars, trucks and other vehicles contain a variety of fluids. Normally, these fluids are contained within their respective components and passages. Over time, however, they can leak while creating puddles underneath your vehicle. Fortunately, you can often identify leaks based on the color of the fluid.


Green fluid is coolant. Most vehicles use ethylene glycol-based coolant, which has a natural green color. If you discover green fluid underneath your vehicle, it's probably a coolant leak.


Orange fluid is also coolant; it's just a different type of coolant. Orange coolant is Dexcool. It serves the same purpose of removing heat from your vehicle's engine, but it uses a different chemical composition that manifests in the form of an orange color. Regardless, if you see orange fluid underneath your vehicle, you should inspect your vehicle's cooling system for a coolant leak.


Amber fluid is usually engine oil. Most vehicles hold around 4 to 6 quarts of engine oil. If your vehicle has a leak, some of this engine oil may gradually escape while creating an amber-colored puddle underneath your vehicle. If your vehicle has an engine oil leak, you should fix it as soon as possible. As more and more oil leaves your vehicle, it can place the engine at risk for catastrophic failure.


Completely clear and transparent fluid with water-like viscosity is typically nothing more than condensation. Condensation usually occurs during the summer months. When driving during the summer months, you'll probably use your vehicle's air condition system. Your vehicle's air conditioning system will produce condensation consisting of water that drips down onto the ground below.


You may notice rainbow-like fluid consisting of multiple colors. Rainbow fluid such as this is typically gasoline. It may look clear when viewed from afar. If you inspect it up close, though, you'll see many different bright colors within it. This rainbow-like appearance is indicative of gasoline. A gasoline leak, of course, is a serious problem that requires your immediate attention.

Dark Red

Finally, dark red color is transmission fluid. Most transmission fluid contains dark red-colored dye as an additive. The purpose of this dye is to make it easier to identify. No other automotive fluid features this same color. The closest is engine oil, which is a lighter amber color. Dark red fluid is usually transmission fluid.