Are you experiencing low engine coolant levels? (Causes & Consequences)

The engine internal combustion unit produces a lot of heat – at times, temperatures hit well over 200 degrees. This heat must be controlled by a cooling system.

Coolant systems in cars are sealed. This means the coolant level must remain even though everything is working as it should.

However, automobiles do not have a reputation for being trouble-free. Therefore, coolant levels may drop.

It is safe to drive with a low engine cooling level. What are the causes? How can I recognize it from my hood without opening it? Let’s find out! But first, let’s take a look at the reasons why your coolant level is low:

Low engine coolant levels are most often caused by cooling system leaks. You can have leaks in the cooling system from sensors and hoses that are leaking, as well as gaskets. It is not a good idea to just top up coolant.

You will find more possible symptoms further down in the article, but first, let’s take a look at the consequences of driving with a low engine coolant level.

The Consequences Of Driving with Low Engine Coolant Level

Driving with low engine coolant will result in an overheating engine. A damaged or blown engine block can result from an overheating engine.

Here is a more detailed list of what can happen if you ignore & drive around with a low engine coolant level:

1. The coolant system contains air

Low coolant could cause you to drive with low fluid levels. The water pump pumps air into your coolant system and this can lead to coolant lockups.

Airlocks will cause the cooling system’s flow to get disturbed, which will cause an overheating engine, which we will talk more about in the next section.

2. Overheating Engine

The coolant system has airlocks that we discussed before. This means the water pump won't circulate coolant around to keep the engine cool. It will overheat the engine.

Overheating your engine can lead to expensive problems. We will discuss these issues in the following sections.

3. Turn off the head gasket

Blowing your head gasket is an extremely common, but not funny, thing that could happen when your engine heats up due to low engine cooling.

Head gaskets are located between the engine and cylinder heads. They separate oil and coolant. The cost of replacing the head gasket can be quite high, with repair costs exceeding 1000 dollars. However, this is nothing in comparison to what's next.

See also: What are the Signs of Bad Head Gaskets?

4. Motor block damaged

A cracked or damaged engine block is another problem that could occur when you have low engine coolant. We have mentioned before that low engine coolant can lead to hot spots in the cooling system.

The engine block can become extremely hot from these hotspots, leading to it cracking. You will need to replace the entire engine block.

5. Seized Engine

Most engine parts are made of metal, and as you may already know – metal expands and shrinks depending on the temperature. The engine can become too hot and cause damage to the parts.

Most of the time, to repair a stuck engine it is necessary to disassemble the engine to find the problem.

How safe is it to drive with low levels of engine coolant?

Low engine coolant levels are dangerous and unsafe. The coolant levels can be low, which can result in airlocks and overheating engines can damage expensive parts such as engine blocks or even seize them completely.

The process of filling up the engine cooler is simple and well worth the effort. Keep in mind that the coolant reservoir should not be opened when it's hot.

Low Engine Coolant Symptoms

Low engine coolant can be characterized by a warning sign on your dashboard indicating low coolant. A low level of engine coolant could lead to temperature fluctuation.

Checking the coolant reservoir is the easiest and most effective way to determine if engine coolant levels are low.

You can also check for other signs. Below is a list that explains the symptoms most commonly associated with low engine coolant.

1. The dashboard displays the low engine coolant symbol

Modern cars come with a warning lamp that lights up on the dashboard when the coolant level is low. This may seem obvious but it is not always available on all cars, particularly if they are older.

It is time to make sure that the engine coolant system level does not appear on the dashboard.

2. A temperature fluctuating gauge

Low engine coolant can also cause rapid fluctuations in the engine temperature between temperatures.

When the engine coolant level is too low, coolant circulates in the coolant system. The coolant will start to drop if there is an airlock around the sensor. When the coolant returns, the temperature will return back to normal.

3. Temperature gauge rising

When the engine is being cooled normally, the dashboard’s temperature gauge will be below the half-way mark. If it moves up over the engine’s working temperature, then a problem needs to be fixed fast.

You should turn the engine off if your temperature gauge reads higher than the recommended temperature of 200 Fahrenheit (or 90 degrees Celcius) to avoid excessive heat.

4. The heater is not turning on

The car’s heater uses the same coolant that runs through the engine. Valves are used to control the car’s coolant inflow; hence, regulating the temperature.

You could have low engine coolant if your heater doesn't work as it should. This is due to airlocks within the heater core.

5. Anti-freeze has a sweet, minty scent

Anti-freeze is a compound included with the coolant to prevent the radiator’s water from solidifying during cold seasons.

The anti-freeze's distinctive characteristic is its sweet scent. The cooling system may be leaking if your engine emits a sweet odor.

Low engine coolant level is caused by several factors

Low engine coolant level can be due to external coolant leaks. However, it is also possible for coolant to disappear in other locations.

This is an extensive list of common reasons for low coolant levels in engines.

1. External coolant leak

We have mentioned before that external coolant leaks are the main cause of low engine cooling. Coolant systems can be leaking from anywhere. External coolant leaks often become visible and can be identified easily.

External leaks are most commonly found around the thermostat, water pump and radiator.

2. Gasket in the intake manifold is defective

Intake manifolds cool the intake air using coolant. They have coolant outlets inside. A gasket is installed between the intake manifolds and the cylinder heads.

The gasket could leak and cause coolant to seep in to the engine. This can be easily identified by the white smoke coming from your exhaust pipe.

Similar: Five Signs That Your Intake Manifold Gasket Is Not Working

3. Head gasket failure

A blown or bad head gasket can also cause low coolant. We have already mentioned that the head gasket helps to separate the coolant from the oil and compression.

An ill-fitting head gasket may cause the coolant and compression to combine, which can lead to the engine cooling down. This can be easily identified by looking out for white smoke coming from the exhaust pipe.

4. Caps leaking from radiators

You will find an open valve inside the radiator cap that is designed to release pressure if it rises beyond a specified pressure. It is possible for this valve to fail, and coolant could leak out if this happens.

This is often visible by looking for white smoke from the engine compartment.

Similar: 6 Signs that a Radiator Cap is Bad

5. EGR coolers that are not working properly

A crack in your EGR cooler is the last thing that could cause low engine coolant. EGR coolers may not be available on all engines. Make sure you check that your engine is equipped with one. These coolers are most commonly found on European vehicles.

Failing EGR coolers can lead to coolant leaking into the exhaust tube, which in turn will produce white smoke.