A stain or puddle or any other visible sign of moisture on your garage floor is almost always a sign of a leak in your car. If you’ve been driving for many years, you know that car fluid leaks are never a good sign. And if this is your first time owning a car, it would really help if you learn how to identify the common types of car fluid leaks and what you can do about them.

Engine Oil Leak

One of the things that you have to understand about an engine oil leak is that it doesn’t really create a puddle underneath your car. If it does, this is usually a very serious concern that you should have a mechanic check your vehicle right away. Generally, engine oil is more viscous than the other fluids in the car like automatic transmission fluid and even power steering fluid. Because of this higher viscosity, engine oil leak will ‘crawl’ or ‘seep’ through the other parts of the car’s engine. As soon as enough oil has accumulated that its weight is greater than the forces keeping them together, that’s when they drop to the surface of the garage floor.

man filling in an engine oil leak

Engine oil has a slightly brownish yellow or light amber or even almost dark golden color. This is if it is the new oil. However, older oil can take on a darker color, usually dark brown. You can also see black oil if it has never been changed for a long time.

Engine oil leaks can be brought about by a number of causes. It can be because of the gaskets in your engine are already deteriorating or there may be bad connections in the hoses that circulate the motor oil in your system. It can also be because of degraded oil seals or leaks in the oil pan. It can be because of an improperly attached oil filter or the oil plug is not tight enough or secured properly. It could even be because of excessively high oil pressure. Whatever the reason it is always best to have a professional check it.

So how do you differentiate an engine oil leak from other types of car fluid leaks? The first thing you have to do is to make sure you know where your engine and transmission is located. It could be up front, which is commonplace for the majority of vehicles, or they could be sitting in the back. What you need to do is to put a clean piece of white paper underneath the engine and leave this overnight. The following morning, check if there are oil stains on the paper.

You may also want to check the consistency of the fluid. It has a really thick and slick feel to it. It is definitely oily and can also smell ‘gassy’. The color, as we already mentioned, is usually light brown to black, depending on the age of the oil.

Transmission Fluid Leak

It is quite easy to diagnose a leaking transmission system. First, the location is a dead giveaway. Again, if you know where your transmission is located, then it would be a lot easier to identify the source of the leak.

Second, the characteristics of transmission fluid are also a great way to differentiate it from other types of car fluid leaks. Generally, transmission fluid is colored red. As such, expect the stain to have a reddish color. Do understand that this is generally the color of transmission fluid that has just been poured into the system. Its consistency is also less viscous than motor oil. Now, if the transmission fluid has never been changed throughout the lifespan of the car, then don’t expect the fluid to retain its characteristic reddish color. Instead, it will have a brownish and thicker consistency.

That being said, you need to make sure that you understand the stain on the paper. If it has a reddish stain it should also have a surrounding halo of really faint stain around it. This is because new transmission fluid is less viscous; it has the tendency to seep through the surrounding area of the principal stain. So you get a red dot with a larger pink corona around it. This is a sign that you have new transmission fluid leaking. If the stain is brownish, then you really cannot expect to see a halo around it since it is usually thicker. As such, you have to be careful since it can look a lot like an engine oil leak.

Transmission fluid leaks occur because of damaged or degraded transmission seals. The transmission fluid line, which is typically made of either steel or aluminum, can also crack or break over time. A crack on the torque pump can also cause transmission fluid leaks. And if you had work done on your transmission system, there’s a chance that some of the components were not installed properly.

oil leakage

Antifreeze or Engine Coolant Leak

If you see a greenish puddle in your garage that appears under the area corresponding to your radiator, there’s a likely chance that you’ve got an engine coolant leak. Now we said it’s colored green because the majority of antifreeze solutions come in green color. However, if you’re using yellow, blue, red, or even orange, then you can expect these colors to be on the stain. If you cannot distinguish the color, try smelling it. It usually has a sweet smell because of ethylene glycol. This is also what makes it especially dangerous for cats and dogs as the ‘sweetness’ of the antifreeze is often interpreted by our pets as something delicious.

It is also important to realize that the antifreeze leak doesn’t only create a stain on the floor corresponding to the radiator of your car. The engine cooling system runs from the radiator to the engine and everything else in between. It is also possible to see a leak between the radiator and the antifreeze reservoir, between the radiator and the engine, and between the engine and the exhaust pipe. You may also want to check the consistency of the fluid. It is quite difficult to describe. It should be less viscous than oil but denser than water.

There can be a variety of reasons for a leak in the engine cooling system. It is possible that the radiator hose is already damaged or the radiator itself is already damaged. The hoses need to be checked as well. It is best to have a mechanic check the problem since your engine’s overall performance is hinged on how well it is able to prevent the buildup of excessive heat inside.

Related Post: Best Anti Freeze

Power Steering Fluid Leak

This can be quite tricky to identify since the appearance of the leaking fluid alone is not often enough to warrant a definitive diagnosis of the power steering fluid leak. Why is that? Well, most motorists also use transmission fluid as steering pump fluid. As such, the leak you see in your car may resemble the leak found in an issue with the transmission. Other car owners put a dedicated power steering fluid. If you’re this kind of motorist, take note of the color of the fluid that you’re using. Check if it is the same color as the one that you saw on your garage floor.

One safe way to determine whether it’s from your power steering or from the transmission is to correlate it with the function of your steering. This fluid is responsible for making sure you get optimum control of your steering wheel. It makes steering a lot easier, often requiring minimal effort on your part to turn your vehicle. If you somehow notice a sluggish response or you find it more difficult to steer your vehicle at the same time that you noticed the leak, then there’s a good chance that you have a leak in your power steering system.

You will also need to check under your car and try to follow the hoses that connect the power steering system. Also, inspect the integrity of the reservoir as well as the power steering pump. Know the location of these parts so you can somehow relate it with the positioning of the stain on the floor.

Related Post: How to Change Power Steering Fluid

Brake Fluid Leak

If you see a colorless or slightly yellowish fluid under your car that has a slightly oily feel to it, there’s a chance that you’re leaking brake fluid. You might also want to check where you found the stain and compare it with the positioning of the brake pedal, the brake fluid reservoir, and hoses. You may even see it near your tires since the brake system of your car is connected to the wheels.

It is always imperative that you bring your car to a mechanic as you don’t want to be driving around town with a leaking brake fluid. This fluid is essential for operating the calipers in your brake system. If you have insufficient brake fluid, the calipers may not function properly and your brake pads may not clamp onto the rotors when you apply the brakes. Technically, it will be very difficult to even depress the brake pedal.

One of the most common causes of brake fluid leaks is damage to the hoses that convey the liquid to the different components of the brake system. Having a mechanic follow the brake lines to check for the integrity of the hoses and connections should help you avert potentially deadly consequences.

Related Post: Best Brake Fluid

Fuel Leak

Sometimes you really don’t need to see any puddle or stain on the garage floor just so you’ll know you have a fuel leak. The smell itself is already a sure giveaway. If it smells like gas, then it’s definitely gas. The question now is where did you see the leak?

A gas leak often takes on a brownish color with a watery consistency. If the stain is found towards the back of your vehicle, there’s a chance that the problem is in the gas tank. If the stain is somewhere located up front, it usually indicates an issue with the fuel pump. It is also possible that a leak may occur anywhere along the entire length of the fuel system.

One of the issues that people have about gas leaks is the risk of having a car blown up in an orange ball of flame. Well, no thanks to Hollywood pyrotechnicians who still manage to convince the movie-going public that a leak in the fuel system can lead to an orange fireball. Not that we’re downplaying such potential scenarios, but you’ve got to understand it simply will not light up that way. What you will have to worry about, though, is the big gaping hole that fuel leaks will create in your pocket. Let’s face it, fuel prices aren’t getting any cheaper.


This is not necessarily a fluid that your car needs to operate properly, but it is something that is the natural product of some of the processes in your car. Your car’s air conditioning system will have to work double-time to keep you and other vehicle occupants as cool as possible especially in the warm days of summer. What you may not realize is that if the environment happens to be hot and humid, your car’s AC will also have to take care of the moisture from inside the cabin. This moisture is drained out to the ground through a hose.

car leaks

As such, you will most likely see water crawling from under the front right portion of your car especially on hot and humid days. In many instances, it would seem like opening a water faucet. The good news is that this is never an issue that you should worry about.

Identifying what type of car fluid leak is present in your vehicle is relatively easy. All you need is to check the color of the leaking fluid and the relative position of the stain or puddle they create on the garage floor. Now, connect these ‘leaky’ findings with other vehicle symptoms and you’ve isolated the problem.


  1. 6 Common Fluids That Can Leak from Your Car, and How to Diagnose Them, LifeHacker
  2. Identifying Auto Fluid Leaks, Angie’s List
  3. My Car is Leaking Fluid: Six Liquids That May Drip from a Car, Axle Addict