How to Check Coolant Levels in Your Vehicle


Car engines, like most machines, generate a lot of heat when running. That is why every car has a cooling system in place to maintain proper engine operating temperature. An engine typically overheats when your coolant is running low. As a driver, you should know how to check coolant levels to avoid damage to your engine.

Here’s everything you need to know about car coolants to help keep your engine in top condition. 

What is a Car Coolant?

A car coolant preserves the car’s engine from too much heat. Some people call it an antifreeze that moistens the active parts of the car and provides the needed protection. A coolant is usually red, blue, green, or yellow in color. To ensure that the engine is secured and free of any damage, an optimal temperature of 2000°F should be maintained. 

The coolant plays an important role in reducing rust in the engine and resisting freezing. Furthermore, it keeps your engine from any rise of pressure and cracking. Recommended coolant brands vary between vehicle manufacturers. Check your owner’s manual for the recommended coolant for your vehicle. 

How Do I Know If the Coolant is Low?

There’s a temperature gauge in your dashboard that tells you if your engine is getting too hot. When your coolant is getting too low, the gauge will indicate a high-temperature. In a normal engine temperature, the gauge normally stays in the center of the H and C symbols. Some vehicles have an antifreeze component that lights up in response to low coolant levels. 

Tools You Need to Check Your Coolant Level

You don’t need any tools to check for coolant level, which makes it one of the easiest car maintenance you could do. However, there are a few things you’ll need when changing an engine coolant:

  • Coolant or distilled water
  • Funnel (if necessary)
  • Flat workspace

How to Check Your Car’s Coolant Level

The coolant level can be found in the side of the reservior. Inspect coolant levels by looking how far it falls on the marking. If it hits the full marking, you’re good to go. If not, you may open the radiator cap when the engine cools down. DO NOT try to open the radiator cap when the engine is running. 

There are two ways to check coolant levels depending on your vehicle. Here are the steps to follow:

Radiator Cap

  1. Once the engine cooled off, open the hood. 
  2. Find the radiator cap and open it. 
  3. Look for the coolant. If it’s on full markings, then it’s okay. But if not, contact your car’s company and ask what kind of vehicle coolant is appropriate for the car. 
  4. Place a funnel on the radiator hole. 
  5. Add coolant and fill it to the brim.
  6. Change the cap or put it back, wipe any residue and close the hood. 

Reservoir Cap

  1. Open the hood. 
  2. Look for the excess coolant reservoir.
  3. Find the Labeling on the side of the reservoir.  (Low or Full)
  4. Check how much coolant is left. If the level hits low, you need to add more coolant.
  5. Using a funnel, fill the reservoir until full. 
  6. Change the cap, clean the sides for any spill, and you may now close the hood. 

When to Change Coolant

The coolant should be changed and maintained according to the car company’s recommendation. Accordingly, the coolant system must be changed when the vehicle reaches at least 50,000 miles of travel. Some vehicles might require below that. Take note that the coolant system should be regularly drained and emptied to ensure that all dust and rust fragments are out of the system. 

Every three (3) to six (6) months, examine the coolant levels. If the color changes to colorless or brown then you may need to consider changing your coolant. 


Can I use water?

Yes, you may but only distilled water. However, it is not advised to use only water for long periods of time. You should have a 50/50 mixture of water and the recommended type of coolant to prevent your engine from overheating.

Can I mix coolants?

Do not mix the coolants. It is best to only use what is suggested for your vehicle. Mixing different kinds of coolants will result in formation of jelly-like substances that could cause your engine to overheat.

How long do coolants last?

Some coolants last longer than others. Thus, it is better to read labels and instructions beforehand. Always look at coolant levels and check for any issues like fluid leaks and others.


Car owners should know what a coolant is and how to check the coolant level. This will greatly help you protect your engine, especially the active parts of the car, such as the water pump, head gasket, pistoning timing and cylinder.

In order to assess coolant levels, open either the radiator cap or reservoir cap and see what marker the level falls on. If it is on the “low” label then all you have to do is add more coolant. When you notice that the color has changed to brown or colorless, then you need to consider changing your coolant.

For optimum engine performance, it is recommended to use 50% distilled water and 50% of the suggested coolant of your car manufacturer. If by any chance you forgot to check your car’s coolant level and your engine overheats, you can always call Neighborhood Roadside Assistance anytime of the day. We have the fastest and most reliable roadside assistance services in New Jersey.