5 Symptoms of a Clogged Radiator and Replacement Cost

As the engine runs, it produces heat. The purpose of the radiator is to cool the engine and prevent it from overheating. You use coolant to push this heat into the radiator which is where it actually cools down. Once that happens, the coolant is sent back into the engine and the process starts over again.

Symptoms of a Clogged Radiator

The cooling system depends on the radiator above all other components. If the radiator does not work well, then there will be no cooling taking place inside the engine. That is why if you have any reason to believe the radiator may be clogged, pay attention to see if you notice one of these symptoms happening that are listed below. If you do, then it is likely a clogged radiator that you have.

1) Overheated Engine

Since a functional radiator prevents the engine from overheating, you will know something is wrong with the radiator if the engine starts overheating. Monitor the temperature gauge and see how often it stays on the hot side. If you see the gauge pointing toward the hot side, even when the air conditioner is turned on, then you may have a clogged radiator. The vehicle will also consume more coolant too. The reason that a radiator gets clogged in the first place is from corrosion, internal deposit buildup, and debris which tends to happen over time. With the radiator being clogged like this, very little coolant is able to make it into the radiator.

2) Hotter Temperature Inside

Sometimes it may be harder to heat up your car if the radiator’s heater core has debris clogging it too. With the heater core clogged, coolant in the engine cannot get into the core in order to bring heat inside the car.

3) Leaky Coolant

The housing or cooling fins may have corrosion forming on them when radiators are clogged. Once this happens, you will be able to see the coolant leaking very easily. If you don’t fix the leak as soon as possible, the radiator may get damaged beyond repair.

4) Damage to the Water Pump

You will have a faulty water pump if parts of the coolant system and the radiator become clogged. If a water pump cannot function properly, then the coolant will not be able to circulate properly either. This could cause coolant leaks which will eventually result in damage to the engine.

5) Damage to the Cylinder Head Gasket

If you have a radiator that’s clogged, coolant won’t be able to circulate. Therefore, the engine will overheat and the head gasket in the engine will stop working. As a result, coolant will get into the oil compartment of the engine and create all kinds of problems and damage that are irreversible.

Estimated Cost to Replace Radiator

To replace a radiator, you can expect to pay anywhere from $533 to $749 on average. The cost of the labor may cost anywhere from $140 to $178. The cost of the parts may cost anywhere from $393 to $571. You will also have to pay the added fees and taxes as well.

Along with a radiator replacement, the thermostat and radiator cap should also be replaced along with it. Also, check everything for leaks and inspect the whole cooling system to ensure everything is working properly. This includes the radiator hoses too.

Read also: 3 Symptoms of a Low Engine Oil in Your Car


To figure out if you have a clogged radiator, try using something called an infrared thermometer. Either that or conduct a radiator efficiency exam by measuring the coolant temperatures going in and coming out. Sometimes you can simply clean a clogged radiator to fix the problem while other times the radiator will need to be replaced if the problem has been left for too long.



  1. My car is not running hot is no leaks we just replace the radiator but when I take the cap off I noticed the antifreeze is not circulating in the radiator and I am concerned about that but like I said there’s no leaks it’s not overheating it’s not running hot so what is the problem

    • Bad thermostat or water pump are the two common causes of coolant not circulating in the radiator although the car would overheat after a while. How long did you allow it to run?

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