The short and simple answer is no. You cannot drive without coolant. The proper amount of coolant is necessary for the regular operation of the engine.
A close friend of mine neglected the symptoms of low coolant in the car. He ignored the signs up until the point where there was no coolant in the vehicle. As he was driving an old car, there was no limp mode activation or engine cut off.
His engine stopped working then and there. The replacement and repair costs of the engine were so exuberantly high that my friend had to sell his car.
These are the consequences of driving without coolant. Let us see these things in detail.
Table of Contents
Cooling System of the Car
The basic function of a car’s cooling system is to keep the temperature of the engine under control. A car’s engine produces an immense amount of heat when running. There is a need to remove this heat and prevent overheating.
The main components/functioning parts of the cooling system of a car are:
Small metallic tubes series in which water flows to remove its heat.
Pathways around the engine in which coolant flows.
Sand casting core holes are filled using these freeze plugs.
Connecting pipes between different components.
Keep the temperature of the cooling system under check.
The water pump pumps the coolant and water mixture in the water jacket around the engine.
The radiator cap acts as a pressure relief valve and covering of the water reservoir of the radiator.
Aid in the process of heat removal from the radiator.
The coolant passes through these series of tubes before returning to the radiator.
When coolant expands, it overflows into the overflow tank to avoid building unnecessary pressure.
What Does Coolant Do?
Coolant is the soul of a car’s cooling system; when the engine starts, the coolant starts running in the water jackets around the engine clock carrying away all the excessive heat.
The series of hoses and cooling fans expedite the process of heat removal from the coolant. The coolant remains at the normal temperature in this way. It keeps performing the function of heat removal from the engine and dumping the heat outside the engine.
What Happens When You Drive Without Engine Coolant?
Following things can happen with your car when you drive without engine coolant.
- Overheating of Engine
- Broken Water Pump
- Damage to Engine Parts
- Automatic Engine Cut Off
- Poor Fuel Economy
Let us see these things in a bit of detail:
Overheating of Car Engine
If you will even try to drive your car without coolant, its engine will start overheating. This is the first sign that something is wrong with your car’s cooling system.
The basic most function of coolant is to carry away the excessive heat produced during the engine cycle. It goes around the engine and this is how it absorbs heat.
If there is no coolant, the engine’s average temperature keeps increasing.
Broken Water Pump
The water pump’s function is to pump the coolant fluid around the engine. Just like a normal pump, it is a pump too. If there is no coolant or low coolant the pump will keep running empty.
If the pump runs empty, it will create bubble holes and air pockets in the path of coolant. This will increase the load on the pump and it can damage the pump permanently as well.
Damage to Engine Parts
Overheating of the engine will only damage the cylinder head and engine block but will also affect other parts of the engine. The coolant cools down almost all engine components where heat may reach.
Parts of the engine that are at the risk of failure due to elevated temperature are:
- Head Gasket
- Piston Timing
- Connecting Rods
- Cams and Pulleys
If these components achieve higher temperatures, it will cause severe damage to them.
Automatic Engine Cut Off
In modern cars, you will experience the engine cut-off function. When the engine senses that there is no coolant inside it sends a signal to the ECU of the car. In order to protect the engine against further damage, the engine cuts off the power delivery from the engine to the transmission.
If you experience this, then make sure to take your car to a mechanic immediately for a cooling system check.
Poor Fuel Economy
Driving without coolant will also decrease the efficiency of your car’s engine. More heat produced in friction would mean more work lost. This in turn means poor fuel economy.
No Coolant in Car; Modern Vs. Old
There are a number of ways to deal with the low coolant issues. Depending upon the type of car you are driving, low coolant levels can have different repercussions.
If you drive a modern car without coolant then there is a long list of safety measures that will be there to protect your car. First of all the power supply to the engine is cut off if there is no coolant in order to stop damage to the engine.
Similarly, modern cars can also go into limp mode. Where they will limit its activity so that they can save the engine even if there is no coolant in the car.
But in old cars, things are different. There is no limp mode as there is no engine control unit. In the same way, they do not have cut-off features like modern engines.
So, you need to be very careful with older cars. You need to keep an eye on the temperature gauge and dashboard light. If the correct working temperature of the engine is not maintained, you must check the coolant manually.
If the coolant level is low, you need to immediately take preventive action.
Coolant Refilling Cost
Depending upon the make and model of your car, it can cost somewhere between $10 and $30 to refill the coolant.
It is recommended to purchase the coolant from an auto shop this way you are sure about what you are putting into your car.
The process of refilling the coolant is not that hard. You just have to open the reservoir cap and pour it in. But it can get really hard if you have to drain out the old coolant and replace all the coolant.
This is what people do often in case of a coolant leak. Labor charges for such tasks can vary between $100 to $200.
It is very dangerous to drive a car with no coolant. Driving your car without coolant can cause engine overheating and an overheated engine can trigger significant damage to core engine parts.
When the car runs, the coolant must flow around the engine block in order to keep the engine temperature under check.
Not only driving without coolant will cause overheating of your car’s engine, but it will also put other parts of your car in harm’s way. Core engine components and other parts of the cooling system like the coolant pump can be damaged in the absence of the coolant.
It would be best if you kept an eye on the high-temperature gauge. If the warning light illuminates and you observe warning signs like a leaky reservoir, sweet smell, and rising steam, you need to immediately take your car to the mechanic.
Frequently Asked Questions
How often you should check your coolant?
You should check your car’s coolant every 5,000 miles or whenever you are changing your oil and filter. However, the coolant system of the car works on a closed-loop basis. So, theoretically, there is no reason why your coolant level should become low.
But in actual you can lose coolant due to a number of reasons like leaky reservoir or faulty pressure cap. This is why you should check your coolant frequently and top it up regularly.
How far you can drive with no coolant in the car?
If there is no coolant in your car, you cannot drive even a single mile. But that is not the case usually. You experience things like engine cut-off and limp mode way before reaching this state in modern cars.
Most of the time the coolant is leaking and you can drive 100 or 200 miles with the low coolant level. But at a limited speed and for short trips only.
Should I drive my car if the temperature gauge is showing a red sign?
No, if the temperature gauge shows a red sign, it means that the engine is incredibly hot. You should not drive your car in such a scenario. It can cause severe damage to the core parts of the engine.
What is the worst that can happen if I drive without coolant?
Many bad things can happen with your car if you are driving with low or no coolant. Your head gasket can be blown away by excessive heat. Permanent damage to engine components is normal but the worst of all you can get is a seized engine. The excess heat will kill your engine for good.
Can my car go into limp mode without coolant?
Yes, modern cars can go into limp mode if low coolant levels. Limp mode is activated to protect the car against irreversible damage. The speed of your car is limited and so is the functionality of your vehicle.