Coolant Hose Leak Symptoms – Which Are The Symptoms?

Coolant Hose Leak Symptoms – Which Are The Symptoms?

August 7, 2021 2 By CarGuy

So, you have been experiencing some suspicious loss of coolant lately? You probably wonder if the coolant is leaking from your coolant hoses and you want to learn more about the coolant hose leak symptoms? You are at the right place; we are going to cover these leaks in detail.

Coolant is probably the most important fluid in your car, without coolant your engine will pretty much overheat. So, paying attention to your coolant level is the right thing to do if you don’t want to have some issues in the long run.

Why I’m saying this? Because without coolant your car will overheat. And if the car overheats your engine will be exposed to some heat torture. This heat can cause the engine head to bend and the block can crack.

If your car overheats too much the most probable outcome will be scrapping the engine. The best-case scenario is to spot the overheating issue on time, but even then, you will have to machine work your head because most probably is bent.

This can cost you a lot of money to repair. That’s why you need to follow your car’s temperatures and if they climb you need to act quickly. So, you need to know the coolant hose leak symptoms.

In this article, we are going to cover everything when it comes to coolant and the cooling system. We also going to cover the coolant hose leak symptoms for you to have a better perspective on these symptoms. Then we are going to talk about how you can fix this issue on the cheap and also with new OEM parts. So, let’s get into it.

What Is Coolant?

Coolant or better known as antifreeze is an automotive fluid used in internal combustion engines in order to deliver proper cooling of the engine.

Most coolants these days are produced from glycol. This ingredient has special thermal characteristics and unlike water, it can cool the car without freezing or boiling.

That’s what makes the coolant so good is the resistance to temperatures. If you are running a regular coolant, for example, you will have some overheating issues. Because water does not hold the temperatures in check like the coolant does.

Coolant can, unfortunately, leak from many places like the hoses. So, what are the hose leak symptoms? Well, we are going to cover that a bit later but first let’s see how the cooling system works.

How does The Cooling System Work?

The cooling system is really simple to understand. The cooling system is basically circulating the coolant inside and outside of the engine.

When the engine reaches the operating temperature then the thermostat opens. This thermostat allows cool fluid to enter the engine and the hot fluid that is inside of the engine goes out of the engine and through the coolant hoses it reaches the radiator.

Here the radiator is showing its great ability to cool down the fluid. If the radiator can’t cool down the coolant on time a secondary fan turns on that cools the radiator down in order to achieve good thermal temperatures inside of the engine.

This system is also prone to leaks, especially the hoses of this system. So, what are the coolant hose leak symptoms? Let’s find out in the next chapter.

Coolant Hose Leak Symptoms

Now we came to the important stuff and that is the coolant hose leaks symptoms. Let’s see what symptom the car produces when there are leaks in the coolant hoses.

  1. Engine Overheating
  2. Leaks Under The Car
  3. Low Fluid In Coolant Reservoir
  4. Bad Engine Performance
  5. Blown Head Gasket

1. Engine Overheating

One of the first symptoms, when your car is losing coolant, is overheating. This overheating will cause many more issues with your engine if you don’t detect the problem on time. So, in order to prevent your engine from overheating. Always check the temperature needle on the cluster.

If the needle goes up, don’t leave it like this and check the cooling system. The first thing to do is to check the cooling level. Remember that this is done on a cold engine and you don’t want to get splashed with boiling hot coolant.

If the coolant is low in the coolant reservoir, then add more coolant to it. Make sure that the level of coolant is always above minimum and below maximum. If there is enough coolant in the reservoir move to the next coolant hose leak symptom and that are leaks.

2. Leaks Under The Car

Check underneath the engine if there are leaks. If there is coolant you will notice some red or green drops. Depending on the color of your coolant. If there are some drops then it’s time to check the coolant level and fill up.

If there are no coolant drops underneath the car then it’s best to inspect the engine bay and coolant piping for leaks. Make sure that your hoses are nice and dry. This will guarantee that you don’t have leaky hoses.

If there are leaky hoses you will need to replace them. We are going to explain later how you can do that. It’s a pretty simple process that can be done by anyone.

3. Low Fluid In Coolant Reservoir

Another in the line of coolant hose leak symptoms is the low fluid inside of the coolant reservoir. If your coolant magically disappears from the coolant reservoir then you have a big problem.

There can be two things. Either your coolant hoses leak, or you are having a blown head gasket.

If there are coolant hose leaks you will notice some fluid under the vehicle. If there is a blown head gasket you will not be able to spot from where you are losing your coolant.

The coolant probably escapes through the engine. Check your oil. If it’s full of sludge then it’s probably mixing coolant with oil. If the oil is ok, then the coolant is probably getting inside the combustion chamber. And if your car produces white smoke 99% is the head gasket.

But no matter what, you should always refill your coolant reservoir with new coolant. You don’t want your car to get thirsty and be left without coolant.

4. Bad Engine Performance

Another symptom of coolant hose leaks is bad engine performance. Since your coolant hose is leaking you are probably also having some overheating issues on your car. These overheating issues are ruining the performance of the engine.

Your engine is designed to work at a certain temperature. And if these temperatures climb extremely high. You are going to end up with an overheated engine that runs poorly.

The poor work of the engine will not gonna deliver any performance out of it and you will probably gonna get frustrated. In addition, it may stall when you least expect and you will not be able to move until it cools down.

So, when you are noticing that the engine is overheating and there is less coolant always fill up your coolant reservoir in order to increase the cooling capacity of the engine.

Since there is also a loss of coolant there are some issues that have to be addressed before you decide to take your vehicle on a long trip.

5. Blown Head Gasket

A blown head gasket is also another one of the coolant hoses leak symptoms. This symptom is a consequence of serious overheating caused by coolant hose leaks as one of the culprits.

The blown head gasket is a condition that troubles a lot of car owners that cannot get rid out of this issue. This issue can only be resolved by dismantling the engine and removing the head.

The head then needs to be inspected and machined. Namely, because it is probably bent from all of the heat that the overheating issue did to it.

If the head is not savable you will probably gonna need to buy a new head for your engine.

All this machining works can cost hundreds of dollars and sometimes even thousands on some expensive cars.

So, the best thing to do when you are having an overheating issue is to do a thorough inspection for leaks and always monitor your coolant level in order not to be left without a coolant.

If you are running the car without coolant, you will probably gonna damage the block as well. Because cracks can form on those spaces where there is no coolant.

If this is not addressed you will probably gonna need a new engine. So, be aware when you are having an overheating issue.

How To Fix Coolant Hose Leak DIY?

If your coolant hoses are leaking it’s a good thing. Your engine is probably not overheated and you can solve this problem with a new coolant hose or a new clamp.

When you spotted the leak on the coolant hose inspect the hose and see from where is leaking exactly. This will help you decide if you need a new hose or a clamp.

If it’s the clamp then you are good to go. Just get a new clamp from the store and tighten out your hose. Wipe the excess coolant from the hose and inspect it for leaks. If there are no more leaks you are good to go.

If your coolant hose is cracking then you will have to replace the coolant hose of your cooling system. For this job, you will need a new hose and new clamps.

The first thing to do is to drain all of the coolant inside a pan. Make sure that nothing is left in the cooling system. Then you are able to remove the coolant hose from the cooling system. Make sure that you untighten all the clamps and then remove the old broken hose.

After removing the old broken hose now it’s time to attach the new hose to your cooling system. Make sure that you install the new hose in the correct way in order to prevent leaks. Make sure that you tighten up the clamps and you are good to go.

After this work. Fill up your car with fresh coolant. Make sure that the water pump spins and clears all the air that is inside of the cooling system and you are good to go.

Coolant Hose Leak Fix Cost

Coolant hoses are relatively inexpensive and readily available online. Depending on your make and model they can come to a cost of $50 to $100.

You should note that you have to find the right hose. Because the cooling system is compromised out of many different hoses. For this, you will need the part number or some expert that will help you out.

If you don’t get the right hose you will have to return it and then all the hassle that goes along. So, before getting a new hose make sure that you get the right part for your car.

Can I Continue Driving Like This?

You can continue driving like this, but always pay attention to your temperatures and the coolant level. Make sure that you fill the coolant reservoir before you decide to go somewhere. Also, fill the reservoir when the engine is cool. You don’t want the hot coolant to splash your face.

But, never try going on long journeys with a broken cooling system. A broken cooling system is not going to take you anywhere. It will break down along the way probably multiple times. This can result in frustrations and more money to be paid on roadside assistance services.


In this article, we learned a lot. We have covered the basics of the coolant and we learned how the cooling system works. Then we have covered all the coolant hose leaks symptoms and those were, overheating, puddles of coolant below the car, low level of coolant, blown head gasket, low performance, and more.

Then we learned how to replace a coolant hose DIY. And lastly, we found out what is the cost of a new coolant hose.

If you are having this issue, don’t wait for the problem to become bigger and your engine to start to overheat. This coolant hose is relatively easy to replace and you can do this DIY at your garage.