Coolant Reservoir Empty (Causes & Fix)

If my vehicle cooling system has issues, is it a problem with the coolant reservoir? Why is my coolant reservoir empty?

If you are in search of the answers to these questions, you are in the right place.

The cooling system ensures that your engine is cooled down at all times and prevented from overheating. Complications with the cooling system could result from an empty coolant reservoir, making the engine hotter than usual.

A Coolant Reservoir is a plastic bottle or container fixed close to the radiator holding excess cooling agent needed by the cooling system.

When you notice a leak in your coolant from your engine or your temperature gauge shows that the coolant is too hot, some others indicate a coolant reservoir empty.

In this article, we are going to discuss how a coolant reservoir works, what steps to take when you notice your coolant reservoir empty, and the cost of fixing an empty coolant reservoir.

Let’s get started!

What Is the Coolant Reservoir, and How Does It Work?

Coolant Reservoir

The Coolant Reservoir is a plastic container fixed close to the radiator holding excess cooling agent needed by the cooling system. It’s easily detected through the radiator pipe, clear when the hood is popped open.

The engine is at work any time you drive your car and needs a variety of coolant at different intervals.

It’s of great importance that your car has a well-functioning coolant reservoir because your engine solely depends on the coolant reservoir for sending and storing coolant in its path whenever necessary.

What Are the Signs That’ll Show Your Coolant Reservoir Is Empty?

If you want to know when your coolant reservoir is empty, below are some signs indicating an empty coolant reservoir;

  1. You turn off your car, open your hood, and you can’t see any coolant in the reservoir while looking at it.
  2. The temperature gauge on the car dashboard shows that your coolant is entirely hot.
  3. You notice a leak in your coolant from the engine and suspect it could lead to an empty coolant reservoir.

Try as much as possible to resolve the problem once you notice any symptoms. Failure or delay could result in you driving a car with an empty coolant reservoir.

As a result, this could result in engine problems, which can be a serious problem for your vehicle. Finding out why your coolant reservoir is empty and the next step to take should be your next option.

Also Read: Power Steering Fluid Leak – Causes & Repair

Reasons Why Coolant Reservoir Empty Problem Appears

Here are some of the reasons why your coolant reservoir is empty

1. Broken Radiator Cap

A crack in the radiator cap is one of the reasons this fault appears. This radiator cap is not simple as the name implies. It regulates and stabilizes your cooling system pressure at 15psi.

Whenever the cooling system exceeds this pressure, a tiny vent on the side of the cap opens and lets out the pressure. This broken radiator cap is what causes the problem.

This cap is designed to detect a cooling system malfunction and stay open. As this happens, the coolant evaporates into the surrounding, but continuous evaporation leads to reduced coolant in the system.

Recall an coolant reservoir empty  causes an engine to overheat, affecting the engine in the nearest future.

Fortunately, the radiator cap is less expensive and can be acquired in any local parts store for only a few dollars. Know that other components in the cooling system need a check once this issue persists.

2. Coolant Hose Leak

Coolant hoses could start leaking if there’s much pressure arising from overheating. Overheating increases pressure and causes the hoses to bloat. Also, the pressure causes expansion in the clamps that fasten the hose and later snap.

A stretched or loosened clamp gives the coolant access to evaporate and quickly disappear out of the surrounding. However, this problem is not a difficult one. You have to get under your car and detect where the leak starts.

You can use a new bolt or clamp to fasten leaky hoses. However, if the cooling hose is damaged, you will need to replace the whole hose. Hoses are often expensive; they could sell for around $50 or even more, depending on the vehicle’s brand and model.

Also, the head gasket should not be overlooked. Usually, when there is a leak in these heads, gaskets cause damage to the hoses.

3. Hole in the Radiator

A hole in your radiator is another reason, especially a damaged radiator from an accident or an old one. Due to built collision, old radiator tends to leak, often causing the coolant in the system to leak through holes and disappear.

To spot a broken radiator is simple. You have to get under your car and detect where the leak starts. If you cannot see any, it’s a small hole, and the coolant must have evaporated.

At this point, the radiator shod be removed and a smoke test conducted.

If you notice smoke flow out of the radiator, you should know you are dealing with a hole. You should therefore patch this hole up. Patching it all up is easy and relatively affordable; there are a lot of shops that handle repair way cheaper.

Replacing the radiator with a completely new one is the best fix you can ever have. A new radiator ensures that you don’t suffer from any more leaks, and your system stays cool than before.

This makes driving enjoyable and saves you a lot of money in the future. Radiators are less expensive, and you can get them for $150.

Also Read: Radiator Repair Options And Which You Should Choose

4. Bad Water Pump Seal

A faulty water pump seal could result in loss of coolant. The seal will keep your water pump in the right place. It is made from rubber and gradually hardens and cracks with time; coolant leaks once it starts to crack.

Whenever you have a coolant reservoir empty problem, try inspecting the water pump for any leaks. If you notice any possible leaks, replace the seal immediately. As you replace the seal, you might want to replace the water pump too.

The long-term cost will be cheaper for you since water pump service is recommended after 60,000 miles. Therefore, if you are close to such, use the opportunity and get a new pump to replace the former. A new seal is a lot cheaper.

Since it requires many components and the water pump to be removed, labor costs tend to be high. We recommend seal replacement and water pump service is done together.

5. Blown Head Gasket

A blown head gasket is not an issue you wish to have on your vehicle. Indeed, they pose a very significant challenge. So, you should try your best to avoid engines that will likely have a head gasket failure.

The blown head gasket is responsible for evaporating the coolant into a compartment known as the combustion chamber or others like the oiling system.

Some white smoke emerges from the exhaust once the coolant occupies the combustion chamber.

The white smoke is a result of the coolant evaporating. Coolant contained in oil causes sludge in your oil, making it thick preventing it from lubricating the engine components appropriately.

A coolant reservoir issue occurs for both conditions, and it gradually drains off if the gasket has holes and the car loses coolant. If the car continues this way and no action is taken like filling up the reservoir, the engine will overheat.

What Should You Do if Your Coolant Reservoir Is Empty?

What Should You Do if Your Coolant Reservoir Is Empty

If you open your car hood and notice you have an empty coolant reservoir, It could be as a result of a leak. what comes to your mind is grabbing a coolant bottle and getting your reservoir filled up.

However, this is not applicable for all cases. The new coolant could function for a while, but that doesn’t mean the problem gets eliminated, and the only thing you are sure of getting it’s a false feeling of security.

Instead of making sure to refill your reservoir, consult a mechanic to know precisely the cause of your empty reservoir. They will probably detect any leak in your coolant that causes your empty reservoir issues.

Is It Safe to Keep Driving With a Coolant Reservoir Empty Problem?

It’s no problem driving like this for a short while until the next step in getting it repaired is figured out. Be cautious; this empty reservoir issue does not appear in the first place.

If it’s left empty entirely, your car will not have enough coolant, thereby leading to engine overheating.

Constantly monitor the coolant gauge. If your car loses more coolant more often, turn it off and avoid driving, this will lessen the problem at hand and stop it from escalating.

Visit your local repair mechanic and inspect your car thoroughly. Having a good mechanic and confirming that a thorough inspection is done makes the problem simple to handle, and finding the real culprit becomes simple.

How Much Will It Cost to Fix an Empty Coolant Reservoir?

As earlier mentioned, driving a car without enough coolant is not advisable. Do your best to fix your car so that your coolant reservoir isn’t empty any longer. Also, prepare yourself for the cost of getting it fixed.

Most times, fixing the cooling system to avoid coolant reservoir empty problems is not expensive. You only need to pay around $25 to get a faulty radiator cap replaced, so you won’t have to worry.

But other instances require that you spend much more than you except for refilling your coolant reservoir.

For example, a water pump replacement will cost you $300 to $750. While a head gasket replacement could be around $1,400 and $ 1,600 on a normal.

Replacing the coolant reservoir, you might be looking at spending around for it. This kind of repair is the only way your car cooling system will be back to work again.

Also Read: Car Leaking Antifreeze When Parked (Causes & Fixes)

Coolant Reservoir Empty – Conclusion

In this article, much has been reviewed concerning empty reservoir issues starting with the basics. What a coolant is, the meaning of a coolant reservoir tank, and where it can be located. These things are important, especially for troubleshooting.

Finally, we have explained the reasons why coolant reservoir empty issues came up and We’ve also learned everything you need to know when dealing with this coolant reservoir empty issue and what your next steps will be.

Scott Greene is a seasoned automotive technician for over 5 years and has been deep into advanced automotive diagnostics for a couple of years. He Loves writing about Automotive Diagnostics and Repair, Trouble codes, Buyer guides for various car parts and accessories, and lots more. 

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