Whether your car, truck, or SUV is a diesel engine, gas motor, electric, or hybrid automobile, it generates heat. As a result, your engine depends on a fluid known as coolant to ensure your vehicle is operating at an optimal temperature. Over time, however, this fluid can become depleted, resulting in your engine overheating and costly engine repair problems.
So, what happens when your car runs low on coolant? In this article, we’ll discuss what happens when your vehicle is running low on coolant and some common signs to look for to prevent causing irreparable damage to your car’s engine.
What Does Engine Coolant Do?
Wondering what is car coolant exactly? Coolant transfers heat and adds antifreeze protection to an engine, so your car can stay running in optimal condition.
Internal combustion engines create energy by burning fuel. Part of this energy is harnessed by the engine and is used to move the vehicle forward. The remaining energy is converted into heat.
A portion of this heat leaves the engine through the exhaust. The rest remains in the engine block itself.
Average combustion temperatures are close to 2,000°F and, in some instances, may reach as high as 4,500°F. Aluminum components melt at about 1,225°F.
A considerable amount of engine failures are related in some way to engine cooling problems. To protect the engine and to keep it running at the ideal temperature, engine coolant is used.
A vehicle coolant performs three very important functions:
- It prevents your engine parts from freezing when it’s cold
- It prevents overheating at very high internal temperatures, and
- It lubricates the engine components when your car is running.
What Causes Coolant Loss?
There are two main causes of coolant loss in cars. The first main cause is a leak in your car’s cooling system. If you notice that the coolant level in your car is decreasing, a leak is the most likely cause.
Some symptoms of your car having a cooling system leak are the sweet odor of antifreeze, an increasing temperature gauge, and issues with your vehicle’s heater. Increased fuel consumption can be another sign of a cooling system leak in your car.
The other main cause of coolant loss in cars is if you do not top off your car’s coolant properly. Your car’s coolant levels could be low because there is not enough coolant going into the reservoir. If so, you should get your car’s coolant topped off properly to ensure that your car’s engine does not become damaged.
Effects Of Driving with Low Coolant
Driving with low coolant can damage certain parts of your vehicle, which could require major repairs. Here are some things that can happen if you drive with low coolant.
Your Engine Could Overheat.
Coolant helps pull heat away from the engine. So, without enough coolant, the engine could overheat or seize up. Continued use of an overheated engine could lead to permanent damage, such as pistons welding to the cylinders.
You Could Blow A Head Gasket.
If you’ve ever said, “I am about to blow a gasket,” to describe your mood — you know that this happening to your engine is bad news! Low coolant can sometimes cause a head gasket on your engine block to blow.
If this happens, you may notice smoke emitting from the engine or tailpipe, a loss of power, engine knocking sounds, or decreased efficiency.
Your Car Could Shut Off.
Some cars have a safety system in place to automatically shut the engine off before it suffers significant damage — which can happen due to low coolant. While this may help save you from extensive repairs stemming from an overheated engine, it can be very dangerous depending on where you are driving when the engine shuts off.
Damaged Engine Block
Driving with low coolant can damage or crack the engine block. This is because low engine coolant can create hotspots in the cooling system. The hotspots can result in extreme temperatures in the engine block, which can cause it to crack.
A crack in the engine block or cylinder head is expensive to repair because the whole engine block has to be replaced. Moreover, a damaged engine block can also mix oil with the coolant, which further damages the engine’s performance.
Seized Engine
Most of the parts in the engine are made of metal, and metal components expand and contract depending on the temperature. If the engine overheats, the engine parts can expand to the extent that they damage and size the engine.
Water Pump Failure
Driving with low engine coolant can also result in a water pump malfunction. The water pump loses lubrication with insufficient levels of coolant. This increases the risk of water pump failure. A faulty water pump failure cannot move the coolant through the engine and radiation causes the engine to overheat.
Five Common Symptoms of Low Coolant
To prevent damage to your vehicle, you need to know the signs that indicate you have low coolant. Below are the top five signs that could mean your car needs coolant.
#1. The Heater System Is Malfunctioning.
A common sign that your car is running low on coolant is when you notice your car’s heater isn’t working how it should. The heater uses the same coolant that feeds the engine. This hot coolant is what allows your heater to function. If no heated air is coming out of your heater, it means you have very low or no coolant in your car.
#2. A Sweet Odor.
Coolant contains an ingredient called glycol. This liquid ingredient has an incredibly sweet fruity odor. This is the ingredient that helps regulate the boiling and freezing point of water. If you’re noticing this sweet odor coming through your air conditioning vents or from under the hood of your vehicle, it means that there is a coolant leak.
#3. Leakage in the coolant.
The coolant can leak internally or externally from the engine. When you are driving back to the home, check the road for a green, orange, or pink leakage. It is an indication of antifreeze leakage. Take your car to the nearest workshop to find a better solution to this issue or simply use the useful maintenance tips for a DIY hack.
Note: The leaked fluid is toxic. Clean it from the floor so that your pet and kids remain safe.
#4. Temperature Gauge Is Red Lining.
Is your car’s temperature gauge displaying the needle near the high-temperature end? If so, one of the reasons it could be doing this is because of low coolant. Your vehicle engine gauge is specifically engineered to tell you when your engine is getting too hot.
When there is low coolant, your engine is not being cooled and is being allowed to overheat, which is when the needle on the gauge will rise to the ‘H’ symbol. Whenever your gauge needle isn’t near the middle, shut your engine down and check the coolant.
#5. High Fuel Consumption.
When your vehicle is losing acceleration or is experiencing a higher fuel consumption than normal, it could be a sign of low coolant. Coolant helps the engine operate properly, so when your fuel is being burned faster, your coolant isn’t feeding into it as it should.
If you ignore these signs and continue to drive your car without coolant, your engine parts will get badly damaged – maybe even permanently – due to overheating. That is why it is very dangerous to drive your car when you are low on coolant.
How To Check The Coolant Level In Your Car?
To check the car coolant level, drivers need to check the coolant reservoir. The tank with min/max markings is the minimum and maximum coolant level. The process of checking the car coolant needs to follow these 4 steps:
- Step 1: Turn off the engine, open the hood, and wait for the engine to cool completely.
- Step 2: Gently twist the cooling tank cap counterclockwise to release excess pressure and open the cap.
- Step 3: If the coolant level is found between the Min and Max lines, it means that your car still has enough cooling fluid.
- Step 4: If the engine coolant level is below the Min line, it is necessary to add more coolant to make the car operate stably.
During this process, drivers should not open the coolant cap when the engine is hot, because then the liquid exits at a high temperature, increasing the risk of burns. Not all coolant products are suitable for vehicles.
In particular, only suitable additives should be used for each type of vehicle to limit damage to the engine. Owners need to be careful in the process of changing the coolant because additives in the coolant are potentially harmful to health.
Summary
It is technically possible to drive your car with low coolant levels, but do not attempt to drive your car if it has less than the minimum coolant level. The two main causes of low coolant are a leak in your car’s coolant system and a failure to top off your car’s coolant levels properly. Low coolant makes it harder to drive in hot weather and sub-zero temperatures. Low coolant also causes your engine to burn fuel more quickly.
You will notice symptoms such as poor fuel economy, a loss of acceleration, and the car’s high-temperature gauge getting close to the red if your car is low on coolant. All of these signs mean that you should put more coolant into your car. Driving your car when it is low on coolant is a bad idea and should not be done if possible.