Car Leaking Green Fluid. What is it & how to Fix it?

Modern-day automobiles are filled with at least 6 different types of colorful fluids. And it is not uncommon for them to leak once in a while. But when your car leaks green fluid that looks like an alien’s blood, it sure is alarming.

So, why is your car leaking green fluid? What is it? And, How do you fix it? Here are all your answers.  

Why is Your Car Leaking Green Fluid?

The only reason your car can leak the green fluid is when you have a coolant/antifreeze leak. It could happen due to a bad hose, physical damage to the radiator, or due to wear and tear, or even due to engine overheating. 

Out of many fluids in the automobile, the coolant is the green one. But while green is the standard color, coolant can also be orange, blue, purple, yellow, and even pink. Different chemicals make different colors.

What remains the same is that these fancy fluids are responsible for keeping your engine cool and effective. And having a coolant leak would reduce your vehicle’s cooling efficiency. The engine would then run hotter and harsher and can seize. 

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What Causes Coolant Leaks?

There are 5 common causes that can cause coolant leaks in your car. Depending on the damage it can be one or many of them. 

Coolant leaks might be caused by:

  • Damaged Radiator
  • Damaged Radiator Cap
  • Blown Head Gasket
  • Failed Water Pump
  • Leak in the Expansion Tank

Damaged Radiator: 

The coolant in your car rotates inside the radiator, to cool down. It starts by collecting heat or absorbing it from the engine block, combustion chamber, and cylinder head. At this point, the coolant is extremely hot and gets cooled inside the radiator. 

A good radiator can last up to 8-10 years, but corrosion can get the best of it. Due to this, radiators start to have small holes and coolant leaks. A leak from the radiator can also happen due to a worn-out sealing gasket. 

Damaged Radiator Cap: 

Every radiator has a small cap called a radiator cap. The cap is used to hold/regulate the pressure inside the radiator caused due to the hot coolant. If the cap or the sealing gasket fails, the highly pressurized hot coolant will spur out. This often happens due to wear and tear of the gasket and corrosion of the radiator cap. 

Blown Head Gasket:

The head gasket of your car seals the engine block and the cylinder head. While head gaskets are good enough to last over 100,000 miles, the rubber can get stiff and brittle faster due to heat and pressure.  

Since the coolant inside the engine is hot and pressurized, a blown head gasket would not be able to hold the pressure, hence causing coolant leaks. These leaks are small at the beginning which later results in big coolant spurs.        

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Failed Water Pump: 

The coolant from the radiator is transferred to the engine using a hose. The hose is connected to the water pump, which circulates the coolant around the engine. A coolant leak can be caused through the pump, if the hoses get faulty, have a loose connection, or wear out seal.  

Leak in the Expansion Tank:

An expansion tank is used in all cars to hold the coolant. It’s generally a white plastic tank located at one side of the engine. While the plastic is durable enough to not melt, the hose connected to it to feed the coolant can go faulty. The plastic tank itself can be physically damaged and start leaking.  

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Can You Fix Coolant Leak By Yourself?

Yes, you can fix coolant leaks by yourself, depending on the level of leak you have. All you have to do is figure out the cause of it. 

For the causes you would need professional help is with radiator leak and blown head gasket. A radiator leak fix can cost you between $300 to $900 while replacing the head gasket can go well above $1500 because of its complexity. 

As for the rest, you can fix it by yourself. Start by inspecting and looking for possible causes of the leak. If you have leaks from the point of connection with the hoses, try tightening the clamps. If the hoses themselves are leaking, you might need to replace them. 

Any of the hose related to coolant doesn’t cost more than $10. Leaks from the expansion tank can also be fixed by duct tape or a simple replacement costing $100. If you get your expansion tank replaced professionally, it can cost $150-$200. 

Finally, the leak from the radiator cap might need a simple gasket replacement or whole cap replacement. Since different vehicles use different radiator caps due to variable pressure, a new cap can be between $50-$250. 

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How Long Can You Drive with Leaking Green Fluid?

As long as the radiator is working and the coolant level is not ‘TOO LOW’ you can virtually drive forever.  With low/no coolant, the engine would seize in 5 minutes. 

A car with a coolant leak can drive for both the long and short term, depending on the leak. If you have a minor coolant leak, with a reduced coolant level, you can drive your car as long as you don’t put stress on the engine. As in revving higher, climbing hills, towing, etc. 

If you have a coolant leak, but you manage to maintain the level by refilling it over and over, you can, well, drive forever. 

But if you have a low coolant light, then you can drive as long as the engine is not overheated. This can be a few miles or minutes, depending on the level. Either way, it is extremely harmful to your engine, so you should avoid it at all costs. 

Is Green Fluid Dangerous for the Environment?

Yes, since the green fluid is a mixture of chemicals, they are harmful to the environment. It doesn’t harm humans unless exposed in high quantities or ingested.  

Coolants are a blend of chemicals with ethylene glycerol and methanol. While direct contact is not hazardous, it is a poison to humans and animals if ingested. A spill is also hazardous for the marine and aquatic life. A spill of it can also pollute groundwater, drinking water, or surface water. 

How to Get Rid of a Green Fluid Mark?

By using dishwasher detergent and scrub, you can remove green fluid marks/coolant stains.  

Coolant marks/ stains are left when evaporated. But since they are water-soluble, they can be cleaned with detergent. To remove those stains; 

  • First, hydrate the area with water. 
  • Then apply dishwasher detergent.
  • Now scrub the area with coolant stain. 
  • Leave it for a while and then rinse it off.