A vehicle’s coolant reservoir that keeps emptying can be a worrying and frustrating issue. It puts your engine at the risk of overheating and damaging various components. If this happens with your car, don’t worry because this article has you covered.
The coolant level in the reservoir decreases based on the amount of driving done. Whether you drive more or less, the coolant level should not drop at an alarming rate. So, why does my coolant reservoir keeps emptying?
Herein, I discuss the causes of a constantly depleting coolant reservoir and ways to resolve this issue. You’ll also know if driving with an empty coolant reservoir is safe.
Answer: How the Coolant Reservoir Works
The coolant reservoir in your car is a translucent plastic container mounted in the engine bay. It stores excess coolant for the engine until required.
You can identify this container with the brightly colored liquid inside, usually red, blue, yellow, green, or orange. This coolant or antifreeze cools down the heated engine as you drive. Without the cooling system, the engine can overheat, resulting in performance issues and engine failure.
You must ensure the coolant reservoir is full for your engine to function optimally. A functional coolant reservoir will supply coolant through the engine and store it when you turn off your car. As the coolant/antifreeze runs through the engine, it absorbs the heat generated, regulating the engine temperature.
The heated coolant passes through the radiator to cool off and goes back to cool the heated engine. This process continues as the engine is running. If the amount of coolant in the cooling system goes down, the coolant reservoir will supply the reserved coolant.
Answer: Signs of an Empty Coolant Reservoir
Checking the coolant level in the reservoir is part of your car’s routine maintenance. But if your coolant reservoir keeps emptying, the routine maintenance schedule won’t be reliable when checking the coolant level.
Several signs will help you know that your car’s coolant reservoir is empty. Below are a few of them:
- High engine temperature: The temperature gauge reading will be high if you have an empty coolant reservoir.
- Coolant temperature warning light: An empty coolant reservoir will cause a warning light for coolant temperature to pop up on the dashboard.
- Leaking coolant: Issues in the cooling system can cause coolant to leak into the engine or on the ground. You may notice a puddle of coolant/antifreeze on the ground under the engine bay. Moreover, if the coolant leaks into the engine, you may see white smoke and a distinctive sweet, syrupy smell while driving.
- No coolant in the reservoir: Your coolant reservoir is empty if there’s no coolant in the container. You’ll need to turn off the engine to check the coolant in the reservoir.
Don’t turn a blind eye if you notice some of these signs. The best way to avoid these issues is to identify and fix the root causes.
Question: Why Does My Coolant Reservoir Keeps Emptying? 5 Causes
Your coolant reservoir keeps emptying due to the following reasons:
- Cracked coolant reservoir
- Faulty radiator cap
- Damaged radiator
- Leaking coolant hose
- Blown head gasket
Cracked Coolant Reservoir
A cracked coolant reservoir could be the reason for depleted coolant in the reservoir. Over time, the reservoir’s plastic material may become brittle and crack, causing a coolant leakage. The reservoir may crack due to overheating, old age, excessive pressure, and vibrations.
When the engine overheats, it stresses your reservoir, causing the plastic material to expand and contract. This expansion and contraction may lead to cracks and coolant leakage with time.
Before fixing a cracked coolant reservoir, determine the cause of an overheated engine and resolve it. If you neglect the engine’s routine maintenance, you’ll experience overheating problems that can damage the coolant reservoir.
Then, examine the reservoir to locate the cracks. If the reservoir has tiny cracks, use a sealant or epoxy resin to cover them. If the cracks are large, replacing the coolant reservoir is always the best option.
Faulty Radiator Cap
The radiator cap regulates the hot coolant’s pressure, preventing damage to parts in the radiator. It serves as a pressure relief valve to prevent excessive pressure buildup in the radiator. Moreover, this mechanical device keeps your car’s cooling system sealed from foreign contaminants.
The radiator cap may wear out or break, rendering the entire cooling system ineffective. A damaged or worn radiator cap can cause coolant to leak from the radiator. When this happens, your coolant reservoir will keep emptying despite being refilled.
If the radiator cap is the culprit, allow the engine to cool and unscrew the old cap. Then install a new cap and screw it properly.
Damaged Radiator
The radiator is a key component of your engine’s cooling system. Its primary role is to regulate the engine temperature, preventing it from overheating.
The radiator continuously works as you drive, resulting in significant pressure inside. The radiator may wear out over time due to old age or corrosion. An old or corroded radiator will form a cavity or hole, causing the coolant to leak. Moreover, a car crash can cause damage to the radiator, resulting in a coolant leakage.
If your engine overheats frequently and you notice an unusual smell from the engine bay, it’s necessary to inspect the radiator. Allow an authorized mechanic to test the radiator for leakages. The mechanic may patch the hole or replace the radiator, depending on the severity of the damage.
Leaking Coolant Hose
Why does my coolant reservoir keeps emptying? A ruptured hose or loose connection points could be to blame for a coolant reservoir that keeps emptying. A defective coolant hose will cause the coolant to leak, resulting in an overheated engine.
Coolant hoses carry coolant between your radiator and the engine. Over time, the hoses may rupture or wear out due to excessive pressure, an overheated engine, or old age. Vibrations or accidents can cause the hoses to get loose and leak coolant at the clamps.
If you suspect coolant hoses to be the culprit, examine them to identify the leaking parts. You can tighten the loose connection points or replace the ruptured hoses.
Blown Head Gasket
The head gasket is a crucial component of the internal combustion engine, serving as a seal to the internal combustion process. It prevents coolant and oil from mixing or leaking into the combustion chamber.
Unfortunately, the head gasket can blow out due to engine overheating, vibrations, age, or corrosion. When this happens, coolant may enter the combustion chamber and burn to form white smoke. Also, the leaking coolant can mix with oil, making the oil less efficient at lubricating the engine.
This leakage will keep the coolant reservoir empty despite refilling it. Replacing the blown head gasket can help resolve this issue.
Question: Is Driving With an Empty Coolant Reservoir Safe?
Driving with an empty coolant reservoir is not safe for your car. While you can start and drive the vehicle, the engine will overheat and damage various components. Even if the repair shop is around the corner, don’t drive with a coolant reservoir that keeps emptying.
Without coolant in the reservoir, the overheated engine may cause permanent damage to cylinder walls and pistons. If you notice this problem, examine the cooling system to identify and fix the defective parts.
Wrapping Up
So, why does my coolant reservoir keeps emptying? In most cases, an empty coolant reservoir results from a cracked coolant reservoir, a blown head gasket, a faulty radiator cap, or a damaged radiator.
If you encounter this problem, determine the root cause before refilling the reservoir with fresh coolant. If you can’t diagnose and resolve this issue, call a mechanic to inspect the cooling system and fix the problem.