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Coolant Leakage Symptoms & Solutions

If you own a car, you must already know how much maintenance goes into it to keep it in perfect working condition. And, in case you have a huge interest in cars, you might also love to fix most of its problems on your own in your personal garage. Well, one problem that most people face with cars is coolant leakage. While the experienced people can differentiate and find out the issue within minutes.

There are plenty of people out there who don’t know much about cars and might not be able to find the actual cause of the problem by just looking at the car’s condition. So, we are here to talk about the most common problem that people usually face with cars, the coolant leakage. And, in this post, we will be discussing everything related to it and also will be telling you how you can diagnose your car and check if your car’s coolant is safe or not.

And, if that’s leaking for some reason, we will also discuss the types of symptoms you might notice in your car’s performance. That said, if you are interested to know it all, make sure to read this post carefully until the end.

What is a Coolant Leak?

Well, the name explains much about it, still, for those who don’t understand well about cars, we will help you. So, as per the name, coolant is basically a fluid that’s used to keep the engine of the car cool. It basically keeps flowing through the entire body of the engine so that the temperatures of the engine can stay balanced and overheating could be prevented.

However, depending on the way you treat or use your car, the car’s coolant might leak which could be a severe problem. If all the coolant from the engine leaks out, there will be nothing left to keep the engine cool while your foot is on the pedal. Therefore, no one could predict how long you will be able to travel in the car before the engine overheats and stops abruptly.

Symptoms of a Coolant Leak

So the question is, how can you identify if your car is going through a coolant leaking problem. Well, the answers are pretty simple, all you have to do is examine the car carefully and check for these few following things:

1. Puddle of Coolant

In case your car has a coolant leakage, and it’s been parked at one place for a long duration. There’s a chance that you might find a big puddle of coolant right beneath your car. The flow at which the coolant is leaking also plays a major role here.

But, if your car hasn’t moved from the place for a long time, you will definitely find a big noticeable puddle under the car. Coolants that most car manufacturers use usually have vibrant colors such as red, orange, green, pink, blue, etc. so that they can be easily identified and differentiated from other car liquids.

2. Engine Overheats

If the coolant leakage in your car is minimal, finding a puddle beneath is not always necessary. However, leakage at a low flow rate is even more disturbing as you will never know about it. So, if you are using your car for going short distances, and still the engine is overheating, that’s a clear sign that your car’s engine lacks coolant.

3. Expansion Tank has Low Coolant Level

Every car comes with a reservoir tank or says expansion tank that holds extra coolant in case the engine coolant level drops, and the car fills it back from the reservoir itself. In case there’s no coolant left in the reservoir tank itself, it means that the car has used all the coolant, so you will have to get it refilled.

In case that is happening quite often and the expansion tank goes empty again after a few days only, it means that the coolant might be leaking from somewhere. Hence, you should definitely visit a workshop and get it checked as soon as possible.

4. Coolant Warning Light is Glowing

Along with the other warning lights, every car comes with a coolant warning light as well. Whenever the coolant level in your car goes low, you will see a warning light glowing in your car which is again, a clear sign of the coolant level is low. Although the coolant is required to be refilled from time to time, if you are frequently seeing the warning light glowing in your car, there are high chances that the coolant is leaking.

5. Bubbles in Radiator

Usually, the radiator pipes and the coolant expansion tanks are properly sealed, so there should be no bubbles inside. However, if there’s a leakage, the combustion gases coming out from the engine can access the radiator or the expansion tank.

As a result, you might notice some bubbles there which is pretty much a symptom of coolant leakage. So, whenever you notice bubbles in the radiator or the coolant reservoir of your car, make sure to get it checked by professionals.

6. Rust or Discoloration of the Radiator

You can also check if your car’s coolant is leaking by checking the condition of the radiator. While the car runs, the radiator is used to get hot, and if coolant leaks and drops on it, it will immediately boil and cause some discoloration or leave a mark there. Hence, if you notice any kind of rusting or discoloration on the body of the radiator, there are high chances that your car’s coolant is leaking.

Causes of a Coolant Leak

Well, as of now, we have explained to you all types of symptoms that your car will show in case there’s a coolant leakage in your car. So, if you are noticing any of the symptoms, you should hurry to any nearby workshop and get it fixed asap!

However, if your car is perfectly fine at the moment, you should have knowledge about the factors that can cause a coolant leak in your car. This way, you will be able to take precautions and avoid such problems before they even happen. That said, here are some of the following factors that lead to coolant leakage:

1. Radiator Hoses are not Sealed Properly

Radiator and the hoses attached to it are definitely going to wear off with time as more and more you use your car. And, to maintain the coolant inside, the radiator hoses are required to maintain a proper seal.

However, if that seal starts to break, which will eventually happen with time, the coolant starts to leak out. That said, it is highly important that you should pay attention to the radiator hoses and make sure they are properly sealed, and if they are a bit old, don’t mind replacing them in the next service.

2. The Radiator Cap is Leaky

Along with a tight seal, there should be a proper pressure level maintained inside the cooling system so that the fluid can flow easily, and the radiator cap is responsible for it. If the radiator cap is itself leaky, it means that there’s no proper seal and the coolant is coming out because the pressure exerts out of the cooling system.

Hence, if the coolant is leaking from the cap, you definitely need to replace it to solve the problem. Otherwise, the coolant of your car will start to leak at a higher rate which can cause other severe issues with the car.

3. Expansion Tank is Damaged

The expansion tank has no other job rather than holding the coolant for your car’s engine. The amount of coolant needed by the engine is automatically withdrawn, and during the time of refill, it’s where you will be filling the coolant as well.

Usually, in most vehicles, the coolant expansion tank is made from plastic, which can show signs of wear and tear over time. Thus, if the tank’s condition is not good, it might break or crack which can eventually cause a coolant leakage.

4. Corrosion within the Radiator

As more and more you use your car, the debris and dust can accumulate and enter inside the radiator through the grills. Well, this is something that happens with almost every car and is unavoidable. When this happens, there are chances that the radiator might get damaged from the inside and even get rusted.

That said, corroded radiators and hoses won’t be able to hold the coolant inside for a long time because of the pressure difference. Corrosion in the radiators is one of the biggest reasons why most coolant leakage occurs, so you should get it checked from time to time and get it repaired if anything’s wrong.

5. Blown Head Gasket

The head gasket is responsible for making the connection between the engine block and the cylinder heads and sealing them. In case the head gasket gets blown for some reason, there will be no seal between the two things, which can eventually make the coolant run out from there. The head gasket can even deteriorate with time, so you will have to keep checking its condition from time to time.

Where May a Coolant Leak Occur?

To make sure that your car’s coolant is not leaking, there are certain places in the car where you can check for the leakage and confirm if everything is fine. As you now know what are the possible reasons for which a coolant leak can occur, you should also know from where the coolant can leak.

1. Hoses

The most common place from where the car’s coolant usually leaks is from the hoses. Hoses usually make a proper seal, but since they consist of materials like rubber for sealing, the rubber can wear with time and even get cracks. If the hoses in your car haven’t been changed for a long time, there are a lot of chances that you might see some coolant leaking from there.

2. Water Pump

If you want to be sure that there is no coolant leakage and the car’s condition is good, don’t forget to check the water pump. Usually, every car uses a water pump to regulate the coolant between the radiator and the engine block to dissipate the extra heat. However, the water pump can degrade with time as most water pumps are just made from plastic. In that case, there’s a chance of coolant leakage from the water pump itself.

3. Reservoir

As we said earlier, the reservoir or the expansion tank that is filled with the coolant is itself made from plastic which again can degrade with time. Thus, it’s highly important for you to maintain your car and check the reservoir’s condition regularly. In case the reservoir tank develops any cracks due to exposure to high temperatures or gets brittle, the clamps holding the hoses might get loosen up. If that happens, there’s a high risk that the coolant might leak from the expansion tank of your car.

4. Radiator

Yet another most common place to check for a coolant leak is the radiator. One of the biggest reasons why coolant leaks from the radiators is that the hoses connected to the radiator usually degrade with time and lose their seal. Moreover, even if there’s an old coolant left in the radiator, it can also cause internal decay to the radiator which can create small cracks in the radiator’s body.

In addition, when the car moves, the houses joined to the radiator tend to get loose because of the vibrations from the road which can eventually cause a coolant leak. Moreover, if your car’s radiator is damaged for some other reason, there will be a coolant leak in that case as well.

5. Head Gasket

While checking for a coolant leak, always remember to check the condition of the head gasket. In case the head gasket breaks or loses its seal, there is a high risk that the coolant will mix up with the engine oil which is not at all good for your car’s health. If the head gasket breaks and the coolant mixes up with the engine oil, you will see a significant color change in the reservoir tank as well. It is because the coolant regulates continuously, and if the engine oil is mixed in it, it will also reach the expansion tank as well.

How to Know if the Coolant is Leaking?

1. External Leak

Finding an external coolant leak is pretty simple and straightforward. However, before you start checking the parts, make sure to go out on a drive for about 10-20 minutes so that the engine of the car gets warmed up so that the cooling system gets activated. After the drive, simply park the car where the floor is dry, and let it cool down for about 15 minutes. Later on, in case there’s a major coolant leak, you will find a puddle of coolant under your car.

If there’s a puddle, it’s a clear sign that the coolant is leaking from somewhere. But to know about the exact leakage point, you will have to check the hoses, head gasket, and radiator properly. You have to make sure that the hoses are properly connected, and whether all the parts like the radiator cap are in a good condition or not.

2. Internal Leak

In case you didn’t find any leakage and didn’t notice any puddle beneath the car, this does not mean that there is no leakage. There can still be some coolant leaking on the inside which might be evaporating from the exhaust system of your car.

While there are so many signs to check for an external coolant leak, there’s just one to find out if there’s an internal leakage. In case your car throws out white smoke, it is probably because of an internal coolant leak. In such cases, the only option you have is to properly check each and every part of the car’s cooling system such as the head gasket, valves, hoses, and the engine block to see if there are any signs of leakage.

If you still don’t find anything and the car continues to emit white smoke, it’s time to go to a workshop and get it fixed. Make sure while you are checking the parts on your own, the car should not be in a warmed-up condition.

How to Fix a Coolant Leakage?

Once you have diagnosed your vehicle carefully and already know that there is a coolant leakage in your car. It’s time for you to try to fix it as soon as possible. In some cases, the leaks are not too severe, so you can also choose to fix it on your own as well. Otherwise, if fixing the condition is not in your hands, it is always a better option to call a professional for help.

What you can fix on your own

  • Using Sealer or Stop-leak concentrate solutions

In case there are minor leaks in your car’s cooling system and coolant is leaking from some minor cracks, you can use stop-leak concentrates or a sealer to fill up and seal the cracks. You can simply find plenty of good sealer options in any nearby hardware store or online stores as well.

  • Changing the hoses

On the other hand, if the leakage is in the hoses, repairing them or replacing them with a new one is the easiest method you can try to stop the leakage.

  • Replacing the Radiator Cap

In most cases, if there’s a coolant leakage from the radiator cap, installing a newer cap will definitely stop the leakage. Maintaining the radiator cap is highly important as this part keeps holding the coolant inside, and if it is weak, the internal pressure of the cooling system will spill out the coolant.

  • Fix the leakage from the Reservoir tank

Apart from that, if the coolant is leaking from the reservoir tank, you should get it replaced as soon as possible. The expansion tank is usually made of plastic which can get brittle with time. Hence, the development of minor cracks is possible from which the coolant can leak out. So, you should watch out and keep an eye on the condition of the reservoir tank of your car.

What you need an expert help

  • Replace the Reservoir Tank

In case you are not able to fix the leakage from the reservoir tank by using a sealer, the only option left is to replace it with a new one. This is one such task that you should not do on your own and should seek professional help.

  • Repairing the Head Gasket

If the head gasket of the car is damaged and coolant is leaking out, you should not proceed with fixing it on your own as there’s a high risk of damaging other parts. That said, you should definitely call an expert if you need to fix the leakage from the head gasket.

  • Replace the Water Pump

One of the possible reasons for the coolant can be a faulty or damaged water pump. Since a water pump is a machine that you can not repair, as they usually get deteriorated with time. Hence, if there’s some coolant leaking out of it, the best option for you to do is replace it with a new one. However, you can not replace it on your own as it’s fitted inside the cooling system which you should not break into. Hence, calling for professional help is advised.

  • Take a test drive

Once you are done with repairing the coolant leakage problem in your car, it’s time to test the car and see if the problem still persists or not. Go on a drive for at least 15-20 minutes so that the cooling system can activate. Thereafter, take a halt and let the car cool down. Then, you can again check if there are still any leakage signs on the parts that you have got replaced or fixed.

How Much Does it Cost to Fix a Coolant Leak?

Since there can be many possible reasons for a coolant leak, the overall cost to fix a coolant leak depends on the type of part which is damaged. For minor cracks or leaks, you can pretty much fix the whole issue just under the $100 mark. It includes the replacement of hoses, clamps, using sealers to block the leakage.

On the other hand, if some part of the car is damaged such as the water pump, head gasket, or maybe the radiator, fixing such parts might cost you around $500 on average. Moreover, if you choose to replace parts, and take professional help as well, the cost will lie somewhere between $500-$1000. That is why it is highly important to take good care of the car and keep it maintained from time to time.


Wrapping up, in this post, we have covered almost everything that is related to coolant leakage. Hence, So far, we have covered how you can diagnose your car for a coolant leak, and also discussed some ways you can try to fix the coolant leakage issue in your car. We advise you to seek professional help in case you are not experienced enough doing such jobs.

It’s always better to take good care of the car and always check if all the parts are in good condition. Because once such problems start to occur, it will definitely hit your bank very hard since such types of repairs are not at all inexpensive. That is it from our side, in case you found this post useful, make sure to share it with your friends as well. Moreover, if you have any queries in mind, feel free to share your thoughts in the comments section below.

2 Responses

  1. Thank you so much for this article and speaking in easy terms to better understand. As an owner of an 2002 BMW 325i car enthusiast this information will help me to understand what’s going on with the coolant system by professional mechanics since I’ll have to take it in to the shop. Hoping it’s a $100 fix not a $1000. Thank you so much!!

  2. Thank you! At least I know it might be possible to fix & am prepared for what I might be paying for repairs if possible.

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