Green Fluid Leaking from Your Car: 5 Common Causes

When you notice a green fluid leaking from your car, it’s understandable to feel worried. So in this article, we will give you what this green fluid is, why it’s leaking, and what steps you should follow next.

What is Green Fluid Leak

The green fluid in your car is typically coolant or antifreeze, which prevents the engine from overheating. This fluid can often be found pooling underneath your vehicle if there is a leak.

Additionally, if you’re seeing green liquid dripping from your car, it’s quite likely that it’s this coolant that’s leaking out. This could potentially mean a problem in your car’s cooling system that needs immediate attention.

Green fluid leak

Green Fluid Leaking from Your Car: Common Causes

Here, we give you potential causes, that lead to leaking green fluid:

Damaged Hoses

Every vehicle is equipped with a system of hoses designed to transport coolant or antifreeze throughout the engine. Normally, these hoses are subjected to high pressure and extreme temperatures, leading to wear and tear over time.

Due to this constant stress, the hoses can become brittle, corroded, or damaged. Often, cracks can develop on the surface, which are hard to notice in the early stages. But as the cracks widen, they can lead to a noticeable green fluid leak.

Similarly, if the hose clamps are loose or broken, they can cause the coolant to leak out. So, regular inspection of these hoses and timely replacements are necessary to maintain optimal engine performance and avoid potential green fluid leaks.

Car’s radiator hose

Radiator Problems

The radiator is a crucial part of your car’s system to cool down the engine. It helps get rid of the heat that the coolant, the green fluid, picks up from the engine. But sometimes, due to different reasons, the radiator can face problems that result in the leakage of this green fluid.

Over time, the radiator can develop cracks or holes due to corrosion or physical damage. So these points can then become the source of a green fluid leak.

Furthermore,  debris build-up inside the radiator can cause blockages and put undue pressure on the radiator walls, leading to leaks. In some cases, the radiator cap or the drain plug may fail, causing the coolant to escape.

Damaged water pump

Another potential cause is the water pump. Normally, you can think of it as the heart of the cooling system. This helps move the green fluid around the engine to help control its temperature. So, the water pump operates under high pressure and is continuously exposed to coolant, which can cause it to fail.

Additionally, the most common cause of water pump failure is a worn-out seal or bearing. When these components fail, the coolant can leak out of the water pump weep hole – a small hole that allows coolant to escape when the pump is failing.

In some instances, the gasket that seals the connection between the water pump and the engine can fail, causing a coolant leak.

Blown Head Gasket

Now, we come up with the head gasket. Normally, it works like a barrier, keeping the engine block and the cylinder head separate. Moreover, during the burning of fuel in the engine, it helps keep the explosion inside the combustion chamber and ensures that the green fluid and engine oil don’t mix. However, if this head gasket breaks or “blows,” the coolant can start leaking out.

Moreover, when the head gasket blows, not only does it cause the coolant to leak, but it can also make the coolant and engine oil mix together. This can change how the green fluid looks, often turning it into a milky or bubbly substance. This is a serious problem that can cause a lot of harm to the engine if not fixed quickly.

Leaky radiator cap

Though the radiator cap might seem like a small and insignificant part of your car, it plays a crucial role in the cooling system. In detail, the cap is designed to seal the cooling system and maintain the correct pressure within it.

If the radiator cap isn’t sealing properly or is damaged, it can allow coolant to escape. This can result in a green fluid leak under your car. It’s a simple yet critical issue that can cause coolant loss and potentially impact the efficiency of your vehicle’s cooling system.

What to Do If Your Car is Leaking Green Fluid

To assist you in addressing the issue, here’s a detailed guide:

Inspecting the Hoses

If your car has started leaking green fluid, one of the first steps you should take is to take a close look at the hoses inside your engine. Remember to do this only when the engine has had time to cool down.

While checking the hoses, look out for any signs that they are deteriorating. This can include any physical damage, rusting, or even tiny cracks on the hoses. If you see any such issues, it’s crucial to replace these hoses to stop any further leakage of green fluid.

Clamp Replacement

Another area to consider when dealing with green fluid leakage from your car is the clamps on the hoses. These clamps have the critical job of keeping the hoses tightly secured, preventing coolant from escaping.

Always keep an eye on these clamps to see if they’ve loosened or broken. If they have, they won’t be able to hold the hoses firmly, leading to potential leaks. In such cases, you need to take action and replace these clamps to prevent any future leaks.

In detail, start by draining the coolant into a container. Next, locate the faulty clamp and remove it along with any damaged hoses. Throw away the old clamp and replace it with a new one, connecting everything back together.

After this, it’s time to refill the radiator with coolant and tighten the lid securely. Take your car for a short test drive to see if the temperature is maintaining a normal level. This is a crucial step in ensuring your car’s coolant system is working correctly and efficiently.

Change Radiator

Should the radiator be identified as the cause behind the leak, a replacement could be necessary. Here’s a simplified guide on how to do it:

  • The first step always involves letting your car cool down before starting. Once it’s safe, disconnect the car battery. After that, find the plug on the bottom part of the radiator, remove it, and let the coolant from the cooling system drain out.

It’s crucial to make sure the drained coolant is disposed of properly because it’s toxic. After that, you’ll need to disconnect any hoses linking the engine to the radiator and take out the thermostat. If there’s a fan connected to the radiator, go ahead and remove it too.

  • Then, look for the bolts keeping the radiator in place and remove them. Now, you can take out the damaged radiator and replace it with the new one. After the new radiator is in place, you can start putting back all the removed components.
  • Replace any parts that might have been damaged in the process. Once everything is back together, refill the radiator with fresh coolant. To confirm everything is working perfectly, turn the engine on and check for any more leaks.”

If you’re not confident in doing the above tasks on your own, it’s best to seek professional assistance. A professional mechanic can accurately diagnose the problem and recommend the most effective repair.

Car’s radiator system

Another Type of Fluids

Next, we’ll provide in-depth details about other car fluids to help you identify and address potential issues:

Red, Orange, or Pink Fluid Leaking From Car

If you see a red, orange, or pink puddle under your vehicle, it can be a sign of a serious issue. This could indicate a leak from the transmission fluid or the power steering fluid.

Also, orange fluid could mean an aging transmission fluid. Over time, transmission fluid can change its color to orange. Alternatively, it could be coolant contaminated with rust from the radiator, giving it an orange color.


Additionally, if you find a yellow fluid puddle under your vehicle. This can lead to leaks from the coolant or antifreeze.

Such a leak could be indicative of wear or damage in these components. These parts might be worn out, or there could be small cracks or holes leading to the leak. You should generally get your car inspected by a professional as soon as you can.


Blue or clear fluid could be windshield washer fluid. This liquid is quite thin and has a scent similar to common window cleaning solutions. While it can come in different colors, like green, a leak in the windshield washer fluid reservoir isn’t typically a severe issue. However, it’s always best to give your car to a mechanic to take a look.

Dark Brown or Light Brown

If the leaking fluid is dark or light brown, it might be engine oil or potentially old, dirty brake fluid. Any oil or brake fluid leak should be addressed immediately to prevent engine damage or brake failure.

Read more: What Does M Mean On A Car: 6 Must-know Information


Discovering a green fluid leaking from your car might initially cause concern, but understanding its likely causes and how to respond can provide peace of mind. Never ignore such leaks, as they could indicate an underlying problem with your vehicle’s cooling system.


  1. What kind of fluid is green in a vehicle?

    The green liquid that you often see leaking from vehicles is typically antifreeze or coolant. This type of leakage is one of the most frequently encountered issues in cars. The source of such a leak is commonly a hose or a clamp that isn't properly secured.

  2. Is it safe to drive with a coolant leak?

    Driving with a coolant leak poses a serious risk of overheating the engine, which is why it's advised to promptly drive to the closest mechanic shop. It's not considered safe to continue driving if the coolant levels in your vehicle are not adequate, as this can potentially lead to a serious engine breakdown.

  3. Does the power steering fluid appear green?

    Typically, power steering fluid has a red coloration. Therefore, it might be challenging to differentiate between a leak of power steering fluid and coolant on your garage floor, especially if your vehicle uses red coolant.