How to Detect a Coolant Leak

What You'll Need
A large jug of water
A car jack
The vehicle manual

Coolant allows the engine to keep operating over extended periods of time without overheating. A coolant leak is one of the most common failures on a car. Detecting a coolant leak can be done in a variety of ways to stop further damage to a vehicle. Here are some ways you can identify the problem.

Step One - Observe

Your first step should be to open the hood and look at the interior of the engine. The most common coolant leaks can be detected by the naked eye. This is because large cracks will often appear on pipes leading to the engine and car radiator. The main cooling pipes will stick out and run to the engine while finer components will be fixed into position beneath the car.

Step Two - Run the Car

coolant dripping under a rig

Sit in the car and turn on the ignition. Open the hood and pour some water into the coolant container. If it drains quickly then it is obviously leaking from somewhere. You should be able to see liquid squirting, dripping, or flowing out of the component that needs to be replaced. It could be from the bottom of the radiator, a hose, or other component. Do this two or three times until you are sure that you know what the problem is and where the leak is coming from.

Step Three - Listen

While the car is running, listen for a humming sound from the front of your vehicle. If there is a coolant leak in the radiator system, this part of the car will make a noise you can detect. This is because the pressure on the radiator is getting so great that it causes small vibrations to occur.

Step Four - Check Controls

If there is no visible leak, there may be a tiny crack somewhere in the coolant operating system. Set your air conditioning to the coldest setting. If hot air still pumps inside the car then the coolant system is failing. Also turn the heat to high and see if nothing but cold air is produced.

Step Five - Check Components

coolant system leak

Turn the engine off and use a car jack to lift your vehicle up into the air. This will allow you to slide beneath the car and get a good look at the cooling system. Use the vehicle manual to read details about each component in the cooling system. Use a reliable light to examine every visible component in turn. If you do not see any cracks, breakages, or other damage, it is highly likely the cooling system has an interior leak or problem.

Step Six - Take to a Garage

If you still have no idea where the leak is coming from, take your car to a garage. They will run a fine liquid through the cooling system that will seep out of even the smallest cracks. It will show up because of the strange colour that it has. If this does not work then the mechanics will most likely take apart the cooling system to examine for a leak. They should be able to identify and fix the problem while you wait.