Car Radiator

Radiator Symptoms, Function & Replacement Cost

In Coolant by 2 Comments

The operating temperature of a car engine is between 90.5 and 104.4 degrees Celsius, as a lot of energy is dissipated in the form of thermal energy due to the high combustion rate in the engine.

This thermal energy must be released efficiently to keep the temperature of your engine within its operating range. If the temperature reaches critical values, the engine will be destroyed. To maintain the temperature, car radiators are therefore used to dissipate heat.

Signs of a Faulty Radiator

Your radiator plays an important role in dissipating heat from your car’s engine to ensure that your engine works properly without breaking down. Over time, the radiator can malfunction for a variety of reasons. The most important of these causes are listed below:

1. Low Level of Coolant

The coolant, which is usually water but should preferably be a mixture of antifreeze and water, circulates around the engine through a pump and is cooled by the radiator. This antifreeze helps prevent water from freezing in cold environments and from boiling in very hot environments. A low coolant level is one of the common and fundamental reasons for overheating. A low coolant level means that less liquid enters the engine, which ultimately results in less heat absorption from the engine or heat dissipation.

In general, the liquid level does not decrease, but due to problems such as seal leakage or pipeline or radiator leakage, the liquid level can drop, leading to overheating problems. If you see a leak in the coolant under your parked car, it is certainly advisable to have the radiator checked, as this can become a major problem.

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2. Overheating

A low coolant level will cause your engine to overheat. A blocked radiator can also cause your engine to overheat. Be sure to check the radiator if you notice overheating. For more information about overheating, see our article: Overheating.

Causes of Overheating by a Faulty Radiator

Choked Radiator

Sometimes radiators are choked by dirt and deposits that restrict the flow of coolant. The main causes of radiator blockages are dirt, dead insects, and debris. This blockage is visible and can be seen from the engine compartment. If nothing is visible, it means that your radiator is clogged from the inside, which can be detected by the infrared thermostat.

Wrong Materials

Radiators used to be made of materials such as copper and brass, but aluminum was later chosen for their manufacture to make them lighter and cheaper. Apart from the cost and weight, it is known that aluminum is much better than copper and brass for cooling. It is, therefore, preferable to have an aluminum radiator fitted to your car if you do not already have one, as the older brass material can be ineffective in controlling temperature.

Faulty Radiator Cap

A defective radiator cap causes the coolant to overflow from the radiator. Radiator cap malfunction is also one of the most common and sometimes ignored aspects of the radiator. If your radiator cap is not properly tightened, the coolant could leak from the radiator and cause engine temperatures to rise.

Faulty Thermostat

Thermostats are not only supposed to switch on and off any compressor-like device, but they also act like a valve that releases and stops the flow of liquid in the motor to absorb heat depending on the motor temperature. If the thermostat malfunctions, it gets stuck and the water in the motor has no room to flow back, causing the motor to overheat. This is the most common problem of all.

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Fan Issue

Sometimes the entire radiator is in good condition, but the fan connected to the radiator no longer works. This may be due to an electrical shutdown or a motor problem of the fan. A malfunction of the fan may result in improper cooling of the liquid. Depending on its condition, the fan can be repaired and replaced if necessary.

Function of a Radiator


Basically, the radiator is a type of heat exchanger that uses coolants such as water to absorb heat from the engine. The coolant flows to and from the engine, which also heats up. This is where a cooling fan, which is mounted right next to the radiator of your car, comes into play.

When the coolant absorbs heat, its temperature rises, but the fan, which is mounted near the radiator, blows out air to cool it down. The blown air cools the coolant to a large extent by convection phenomenon. This continuous cycle, in which heat is absorbed by radiation and released again by convection of the fan, helps to maintain the engine temperature of the car.

Modern radiators are made of plastic-aluminum. And although the heat transfer rate of aluminum is lower than that of brass, the larger size of aluminum radiators help to cool the engine faster. They are made by brazing thin tubes of aluminum fins and flattened aluminum tubes. For every two rows of copper or brass coolers needed, only one row of aluminum tubing is required.

Thermostats are also fitted to the front of the engine to detect when the engine temperature exceeds the limit value. As soon as the temperature rises, water and coolant are released from the radiator, which absorbs the heat generated by the friction of the engine and the burnt fuel. The surface of the radiator is kept large enough to allow the fluid to cool. In addition to placing the fan, air from the surrounding environment is introduced through openings that keep the engine cool.

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Radiator Replacement Cost

The core is the largest and most important part of the radiator. It consists of large metal blocks with small metal ribs. Through this block area, the heat from the coolant is released to the environment. A variety of cores are available in radiators with one, two, or three cores. It is preferable to replace the radiator if this part is damaged.

Perhaps due to a temperature change, the cooling system experiences high pressure. A cover placed on the cooler helps to generate this pressure by means of a spring attached to it. It is very important that the radiator cap is not removed when the coolant temperature is high as this can cause severe burns. In case the radiator cap is lost or does not work properly, you can simply get a new radiator cap instead of replacing the entire radiator.

Radiators also have outlet and inlet reservoirs. These tanks help the radiators to transport the hot areas of the coolant from engines to a radiator. Any leakage can be repaired or, if necessary, the entire tank can be replaced separately. In general, a cooler replacement will cost you $350-$400 including labor.

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2 thoughts on “ Radiator Symptoms, Function & Replacement Cost ”

  1. Why does my Dodge Durango loose antifreeze changed the Top upper hose water pump seem to be no air in system no heat inside vechile it will have heat for 2 days then nothing also changed thermostat like I said heat for couple of days then have to put coolant in again can’t find no leaks checked oil good and black no white smoke coming from exhaust what got it be

  2. Hi. I am Ndumiso from Keiskammahoek.
    I am drivi ng nissan almera 1.6 luxury 2004 model. Problem: water boils in the resevour bottle and it starts heating. No water in the radiator. New radiator cap but thermostat is taken off. I therefore want to know what might the problem be?

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