If you have noticed any mysterious puddles under your car lately, this week’s topic is for you. Leakage under your car may indicate a number of issues from transmission problems to power steering system trouble. Before you take your car in for inspection and diagnosis, you can perform a simple inspection on your own, so you know what to expect.

If the area below your engine is exposed, without a protective shield beneath it, there is a simple way to help identify the leak source. Begin by parking the car over a large, clean piece of paper or card board and leave it there overnight. It is a good idea to mark the paper to indicate position so you will know where the leaks are relative to front, rear, right side, left side. In the morning, move the car and examine the leakage:

• A clear, watery leak located near the air conditioner is likely to be normal condensation from running the system.
• A blackish, greasy leak located under the engine area is probably oil. Depending on where you see the stain, pop the hood and look for leaks around the oil filter and the engine. The leak might also be around the oil drain plug or crankcase and oil pan.
• A thick, dark, oily leak may indicate a gear oil leak from a manual transmission, differential, an axle, or the steering gears. These leaks should be checked right away.
• Slippery, watery fluid that is green, red, blue, or yellow and coming from under the engine or radiator is likely to be coolant. Check the radiator, pressure cap, engine, and hoses for leaks.
• An oily leak that is reddish or clear and located toward the front might be power steering fluid.
• A leak that is light-colored or clear could be brake fluid. Leaky brakes need immediate professional repair.
• Battery acid leaks usually smell like rotten eggs. Avoid contact with battery acid and have the battery replaced.
• Fuel leaks are also possible and usually recognizable by the smell. Check around the fuel pump and the fuel injectors. If the leak seems to be under the center of the vehicle, it could be the fuel lines, or if it is toward the rear, it could be the fluid tank.

It is extremely important to approach all checks with great caution, and exercise appropriate precautions to avoid injury. If your leak continues, or you still aren’t sure how to tell what it is, make a service appointment as soon as possible.