Troubleshooting a Leaking Radiator Troubleshooting a Leaking Radiator

A leaking radiator can be very dangerous if the leak is not found and fixed quickly. The radiator in a car helps to keep the engine cooler and distributes heat away from the engine, thus allowing you to use a car for longer periods of time. This system stops many internal parts of the car from becoming too hot and failing. Troubleshooting a leaking radiator can be carried out using a variety of methods.

Electronic Displays

The first step to troubleshooting a leaking radiator is to look at the electronic display on your dashboard. The display monitors oil temperature and oil pressure and will signal a warning light if something is wrong. Start your car and allow it to run for a few minutes while all of the parts heat up. If the displays or dials are in the red areas, there is a good chance you have a leaking radiator that has to be fixed.


Many leaking radiator systems can be defined by monitoring the coolant reservoir tank. This holds a large amount of water that is used to keep internal parts of the car cool during long journeys. If the tank is empty or just above the minimum advised level, you are likely to have problems with your radiator. You can troubleshoot this problem quite easily irrespective of whether you have a coolant tank or a radiator. Pour a liter of water into the tank. If it drains quickly, the coolant tank will have cracked. If it doesn't, the chances are that radiator will be leaking and observations should be made for this instead. Some cracks can be very small so use tissues to wipe the tank dry and look for fresh moisture marks.

Check Beneath the Car

There are two ways to troubleshoot a leaking radiator by looking beneath the car. Raise the car with a jack until you can easily slide beneath the car to check the radiator. Start by looking for any puddles on the ground. Many professional coolants are green so look for colored wet patches. The next step is to slide beneath the very front of the car and check the cross beam area just below the radiator. Use a cloth or your hand to check for any wet spots. A good tip is to leave a piece of cardboard beneath the hood of your car on a cold night. Any leaking water will freeze onto the cardboard and you will know the area of the radiator that is damaged.

Remove Radiator Cap

Open the hood and remove the radiator cap when the car is cold. Visually inspect the radiator for any signs of cracks. Take a liter of water and pour it into the radiator. Many radiators leaks are caused by damaged or worn hose clamps that connect to the radiator. Run a cloth over the hose clamps to see if any moisture is present. If the engine is cool, feel around the reachable parts of the radiator with your hand to see if there are any damp spots.


Most problems that you come across can be rectified very easily. Small leaks can be solved using either radiator pellets or radiator weld. Larger cracks causing larger leaks could mean that you will have to get this area of the radiator professionally repaired or replaced.



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