6 Signs of a Bad Radiator

Undoubtedly radiator is the most important part of your cooling system, but you must know when something is wrong with it. How can you tell that your radiator has a problem? Unfortunately, most drivers don’t know the signs of a bad radiator. Even if you are not a professional mechanic, you must understand the mechanism of this part of your vehicle for any unexpected emergency situation.

This article will inform you about the working of the radiator, how to specify symptoms of the bad radiator, and how to address these issues.

What is the Radiator?

A vehicle radiator is one important part of the cooling system that enables your engine to operate at ideal temperatures. The front part of your engine contains a heat -exchanger which comprises two linked water tanks connected by small tubes. The Assembly works such that the hot coolant comes from the engine and is transported into the core through one of the pumps.

As you drive your car, the narrow tubes get the colder air. This mechanism absorbs all the heat from the coolant. This cooling solution is then transported out of the radiator and reversed into the engine.

6 Signs of a Bad Radiator

If your radiator and cooling system is not working properly, you may notice lots of symptoms. Following are some of the common signs of a failing radiator:

1. Overheated Engine

Overheated Engine



One of the most common symptoms that something is wrong with your cooling system and radiator is the overheated engine. This may be due to a defective thermostat. Then a faulty thermostat no longer operates, and your engine’s temperature will start to rise and ultimately break down.

2. Leakages


Car coolant leakage

You may observe coolant deposits under the vehicle, these are symptoms of coolant leakage. It can be either yellow, red, or green fluid. If the radiator is leaking, the coolant level will decrease. The low-level coolant will not be able to prevent the engine heat. As a result, your engine will quickly overheat.

Normally radiators are made of plastic and metal. Since plastic is not as strong as metal, therefore, it is a normal practice for these components to come brittle and crack, leading to leakage.

3. Shifting Problems


If your vehicle has an integrated arrangement of transmission cooler, you may observe problems with shifting as the fluid becomes polluted with the coolant.

4. Fluid Discoloration


Fluid Discoloration

Normally the vehicle coolant is green or yellow in color, but at times it is red or pink. It flows smoothly to the coolant passages and the radiator in your engine.

A bad radiator’s sludges and deposits can cloth the coolant and turn it into rusty color just like oil. You should examine the color of your coolant overflow. If you find it contaminated, it may also look thicker. Such fluid can not flow smoothly through the engine and the radiator and ultimately lead to a blocked radiator. You may find a radiator flush helpful in this case.

5. Blockage/Bent of Exterior Fins

Exterior Radiator Fins Blocked


Radiators require maximum airflow for proper cooling. Small fins like tubes running in front of the radiator transport the hot coolant away from the engine. When the car is moving, the air passes through the fins to decrease the temperature of your engine.

If this means becoming blocked by dust, leaves, bugs, debris, or dirt airflow can become diminished. This will not allow the coolant to reduce the temperature as required. Many vehicles have an option to spray the radiator with a garden hose to increase the airflow.

Air blockage is also possible due to bent or damaged fins. Radiator fins are very fragile and delicate and can be easily destroyed by any debris or flying dirt. You may also damage them during installation or water spray, especially if the water is flowing with high pressure. If you have damaged radiator fins due to any reason, there is a possibility of radiator blockage, leading to the engine overheating.

6. Cabin Heater Not Working

Cabin Heater Not Working


Another prominent symptom of a bad radiator is when your passenger cabin heater does not perform as it should. The passenger cabin heater gets the required heat from the hot wheel and that passes through the engine core. If the radiator is clogged or leaking, you may not get sufficient heat from the heater on a cold winter day. Sometimes an improper working heater is due to a faulty thermostat. Most auto repair agencies offer both radiator and thermostat inspection Services.

How to Diagnose a Bad Radiator?


There are a large number of components working together in your engine, so you cannot say precisely that it’s a bad radiator unless you already know about the problem. Your mechanic will perform a group of tests to find the exact faulty parts. You will require an infrared temperature gun to test your thermostat’s condition.

Check No. 1: Failed Thermostat

You have to get an infrared temperature gun followed by the following easy steps:

  • Start your car and give enough time to your engine to warm up.
  • Locate the radiator hoses, It has an upper and lower hose.
  • Examine the hose temperatures with the infrared gun. Let your engine overheat and measure both hoses.
    In case only one hose becomes hot or both stay cold, you have a bad thermostat. Never try to measure the temperature by touching the hoses. They will obviously be very hot and would surely burn your hand.
  • Clean radiator external clog using a garden hose.
  • You must clean the external clock with compressed air for the garden hose.

Check No. 2: Blocked Radiator

If there is an internal blockage in your radiator, the coolant flow will be obstructed. While if there is an external clog, it will reduce the airflow leading to engine overheating. Here is a list of necessary checks:

  • Let your engine cool down. Park your vehicle until it’s completely cool.
  • Observe the interior of the radiator by removing the cap and inspecting for debris. If you find an internal blockage, you should replace the radiator.
  • Now observe for external blockage by examining the front of your radiator Ford Everest that may have clogged it. You must clean the external clog with compressed air or a garden hose.

Check No. 3: Inspecting Cooling System Leakage

Your cooling system has a leakage it will surely overheat your engine. You must go for its immediate repair to stop any further damage. In order to perform the cooling system check, you need a coolant die kit and cooling system pressure tester. Follow the following simple steps:

  • Completely cool your engine.
  • Remove the pressure cap and place it somewhere safe.
  • Now apply pressure with your tester in accordance with your manufacturer’s instructions. Never exceed the limit printed on your
  • radiator cap.
  • Inspect the system for leakage.
  • Add some coolant dye after completing the test and removing your tester, if required.
  • Place the radiator cap back and start the engine.
  • Observe any leakage of the dye. In some cases, it can take up to several days of normal driving until you observe the dye leakage. This means a slow leak.

Check No. 4: Faulty Cooling System Pressure Cap

Is there any possibility that a bad radiator cap causes overheating? The simple answer is, yes. If your cap cannot hold pressure, coolant will quickly start to boil and lead to an engine overheating. You have to have a system pressure tester to perform this check as well:

  • Entirely cool your engine.
  • Remove the pressure cap by unscrewing it.
  • Place the pressure tester on the cap. Make sure it has the recommended amount of pressure as written on the cap, if not, replace/fix it.

Check No. 5: Field Water Pump

When your water pump is not working properly, it does not allow the smooth circulation of coolant in the proper amount. This will simply lead to an overheated engine. You should never perform this check until you have done the thermostat examination first. To perform this test follow these simple steps:

  • Entirely cool your engine
  • Remove the pressure cap.
  • Start your engine and observe the coolant if it starts circulating.
  • If it does not circulate, you may need a water pump.
  • Now observe the water pump. It may have signs of leakage. Dry green or white residue or even wet spots are leakage symptoms.

Check No. 6: Defective Head Gasket

Everyone desires to avoid any serious internal engine problem, but it may occur. The best way to avoid engine errors is to go for cooling system repair as earliest as possible. This means, only putting water in your radiator but ignoring all the leakages. In order to perform this check, you require a block test kit:

  • Completely cool your engine.
  • Place the block tester in accordance with the manufacturer’s specifications.
  • Observe symptoms of the gas combustion engine cooling system. If there are any symptoms of gases, you require to disassemble the entire engine for more troubleshooting.

Check No. 7: Damage Radiator Cooling Fan

Cooling fan failures will ultimately lead to engine overheating. Follow the following steps to perform this check:

  • Stop your car.
  • Find the cooling fan in your engine. It might be electrical or mechanical, but the engine powers it.
  • Now start your engine and let it warm up.
  • When the engine temperature reaches a higher level the normal, examine the cooling fan. If it does not turn on or runs slowly, this may be your problem.
  • Now for a mechanical fan, you should replace the clutch.
  • You must diagnose the circuit fast in the case of an electric fan.

As you observed that finding a bad radiator is a pretty complicated job. This is because of the fact that the cooling system contains multiple components, and any of them working improperly will lead to the same overheating symptoms. You cannot directly say that radiator or thermostat is the reason only because the engine overheats.

Other Parts that May Contribute to a Bad Radiator

If the radiator collapses, it will also fail other components. The three main parts that you should inspect are our water pump, heater core, and thermostat.

1. Water Pump

Radiator Water Pump


Your engine requires a working water pump to properly transfer the coolant into the hoses and passages of your cooling system. Generally, it is made of plastic, therefore, if the radiator has a lot of diabetes, it may damage the water pump or abrasions. If the flow is interrupted, your water pump will completely collapse.

2. Heater Core

Heater Core


The heater core in your car looks like a small baby radiator. It has almost the same working assembly but has a smaller body. The main responsibility of the heater core is to give warm air into your passenger cabin. When the miniature heater core attracts debris from the faulty radiator, it will not be able to give you appropriate heat.

In addition, when the engine overheats, the heater core fails under intense pressure and temperature. In this case, your floorboards will become wet from leakage, and inside of your car windows will start to fog.

3. Thermostat



The thermostat must perform its job accurately to properly control the engine temperature. It is located at the end of the top radiator hose. It controls the flow of coolant in the cooling system. As your Indian temperature reaches a specific point, the thermostat opens up and allows the cooling system fluid to flow smoothly.

When the radiator stops working properly, there is an extra workload on the thermostat. This leads to the thermostat malfunctioning. Normally the thermostat valve stop opening and closing freely. If it doesn’t open, the ultimate result is the engine overheating. You can know if the thermostat is stuck by touching the radiator hoses. In this case, you will feel the top hostess hot and the bottom hose will be cold.

In the other case, if the thermostat gets stuck in an open state, it will not allow the engine to reach the appropriate temperature. This severely affects the fuel economy and makes your car use more fuel. Therefore, it is really important for you to get your damaged radiator fixed immediately. Otherwise, it can damage your other cooling system parts even your entire engine.

Frequently Asked Questions about the Cooling System

Can you drive with a bad radiator?

A bad radiator has serious effects on the performance of your vehicle. Overeating can lead to a failed gasket and other serious damages to your engine. A continuous drive with a damaged radiator can cause costly repairs and additional damages.

If you ever observe that your engine is overheating, the best solution is to park your car and let it cool down. If you are completely unable to drive it at a normal temperature, you must call the tow service to get you to the local workshop. It is a general observation that people do a lot of damage to their engine before finally deciding to tow their car to the workshop. Sometimes it’s not the solution to put water in your radiator and keep driving. You would actually be making larger trouble by allowing the cooling system components to rust out.

How much does it cost to replace the radiator?

The common cost of radiator replacement is about $800. However, this price can vary substantially depending on the model, make, and year of your car. It also varies with labor costs, since some states have cheaper labor rates while others have higher ones.

How long does the radiator last in a car?

Normally radiators and long life, and should survive in the vehicle forever. But that does not always occur. It may break earlier and ask for premature replacement. However, the conjuring perception is that a well-maintained radiator should easily survive for 8 to 10 years.

What are the symptoms of a bad radiator cap?


bad radiator cap


There are two typical methods that can be used to tell if the radiator cap is bad or not.

  • Visual inspection for wear or damage.
  • Testing through cooling system pressure tester.

1. Executing a Visual Inspection: If you find that the cap seals are damaged or worn or the cap is compromised in any way, the best-recommended solution is its replacement. It is obvious that a cap that leaves the coolant given when the system is not under severe pressure, is simply broken. Capsules are not very expensive, so if you find them damaged, go ahead and replace them.

2. Testing with Cooling System Pressure Tester: The experts will test your radiator tap using a cooling system pressure tester. A special adaptor is used to connect the device with the cap. The next time, a certain amount of pressure is pumped to the cap as specified by the manufacturer. If you have a good cap, it will nicely hold pressure for a short time, therefore, degrees to pressure after some time.

It is because of the fact that pressure tester is quite more costly than radiator cap replacement. Therefore, in order to keep your engine secure from overheating and costly repairs, a smart idea is to replace any questionable radiator cap.

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