When it comes to a car's cooling system, most drivers imagine only one radiator - the one located in front under the hood. However, modern machines are equipped with multiple heat exchangers, each with its own unique function. Not only the comfort in the cabin, but also the service life of the engine, gearbox and even electronics depend on their serviceability.

In this article we will look in detail at how many radiators are in a car in fact, where they are located and what they are responsible for. You will learn how heat exchangers differ in gasoline, diesel and hybrid cars, as well as how to diagnose them if they break down. The material will be useful to both beginners and experienced car owners who want to better understand the structure of their vehicle.

1. Main radiator of the engine cooling system

This is the largest and most visible heat exchanger, which is located in the front part of the engine compartment, immediately behind the bumper. Its main task is to remove excess heat from coolant (antifreeze), which circulates through the engine jacket. Without this radiator, the engine will overheat after 5–10 minutes of operation.

Structurally, it consists of an aluminum or copper core with many thin tubes and ribs that increase the heat transfer area. A fan installed behind the radiator forces air onto it, especially when the car is stationary or moving at low speed. In modern cars they are often used double row radiators - they are thinner, but more effective due to the larger contact area.

  • 🔧 Material: aluminum (90% of modern cars) or copper (old models, for example, VAZ-2107)
  • 💧 Antifreeze volume: from 5 to 12 liters depending on the engine
  • ⚠️ Frequent problems: leaks at the seams, clogging of honeycombs with insects or dirt
⚠️ Attention: If, after stopping the engine, a hissing sound is heard from under the hood, this is a sign antifreeze overheating in the radiator. Immediately check the coolant level and inspect the radiator for leaks.

2. Interior heater (stove) radiator

This heat exchanger is responsible for heating the interior in winter. It is built into the engine cooling system and works on the same principle: hot antifreeze passes through the radiator, and the heater fan blows air through it, heating the flow entering the cabin. It is usually located behind the dashboard, next to the passenger’s feet.

Unlike the main radiator, the stove has adjustable antifreeze flow — its intensity is controlled by the heater tap (in old cars) or an electronic valve (in new cars). In hybrid and electric vehicles, the heater radiator can be heated not from the engine, but from a separate heating element (for example, in Tesla Model 3 or Nissan Leaf).

  • 🌡️ Outlet air temperature: up to 80–90°C (depending on climate control settings)
  • ❄️ Frequent problem: clogged stove radiator due to old antifreeze or corrosion
  • 🔧 Cleaning methods: washing with special compounds (for example, LIQUI MOLY Kuhler-Reiniger) or mechanical cleaning after dismantling
📊 How often do you check the operation of the stove?
Every season
Only if it stops heating
Never checked
I service my heating system myself.

3. Automatic transmission radiator

Automatic transmissions generate enormous amounts of heat, especially during heavy driving or towing. To cool them, a separate radiator is used, which can be:

  • 🔄 Built-in into the main engine radiator (more often in budget cars, for example, Hyundai Solaris)
  • 🚗 Remote - a separate heat exchanger installed in front of the air conditioning condenser (typical for SUVs, for example, Toyota Land Cruiser 200)

It is not antifreeze that circulates in the automatic transmission radiator, but transmission fluid (ATF). Its temperature normally should not exceed 90–100°C. When overheated, the oil loses its properties, which leads to accelerated wear of clutches and gearbox bearings - this is one of the main reasons for automatic transmission breakdowns after 150–200 thousand kilometers.

Automatic transmission radiator type Benefits Disadvantages Examples of cars
Built into the main radiator Compact, cheap Risk of mixing ATF with antifreeze due to leakage, less efficiency Kia Rio, Renault Duster
Remote (separate) Better cooling, less risk of overheating More expensive, takes up space under the hood BMW X5, Ford Explorer
With additional oil cooler Maximum protection against overheating Complex design, high price Mercedes-AMG G63, Porsche Cayenne Turbo

4. Air conditioner condenser: radiator or not?

Many people confuse the condenser (aka condenser) of an air conditioner with a radiator, but these are different devices. The condenser is part of the air conditioning system where the refrigerant (freon) changes from a gaseous state to a liquid state, releasing heat to the environment. In fact, this is also a heat exchanger, but it works not with liquids (antifreeze or oil), but with gas.

The condenser is located in front of the main radiator - this way it is better blown by the oncoming air flow. In modern cars (for example, Audi Q7 or Volvo XC90) the condenser is often equipped with a separate fan for additional cooling. Its malfunction leads to:

  • ❄️ Poor interior cooling (the air conditioner blows warm air)
  • 💰 Freon leakage and expensive repairs (refilling the system costs from 3,000 ₽)
  • 🔥 Overheating of the air conditioning compressor (risk of failure)
💡

If the air conditioner becomes worse at cooling, check the cleanliness of the condenser - often its honeycombs become clogged with poplar fluff or road dust. You can clean them with compressed air or a soft brush.

5. Radiators in diesel and turbocharged engines

Diesel engines and gasoline engines with a turbine have additional heat exchangers due to increased thermal loads:

  1. Intercooler — cools the air entering the engine after the turbine. Hot air is less dense, so cooling it by 10–15°C increases engine power by 5–10%. Located in front (for example, in Volkswagen Golf GTI) or above the engine (in Subaru WRX).
  2. Oil cooler — cools the engine oil, which in turbocharged and diesel engines heats up to 120–140°C. Without it, the oil quickly degrades, losing its protective properties.
  3. EGR cooler - reduces the temperature of the exhaust gases returned to the intake manifold (recirculation system). Often fails due to carbon deposits (a typical problem for Opel Astra H or Peugeot 308).

In diesel cars (for example, BMW 320d or Mercedes OM642) the oil cooler is often combined with the automatic transmission radiator into one unit - this saves space, but complicates repairs. If such a block leaks, you have to replace the entire assembly, which costs 15,000–30,000 rubles.

What happens if the intercooler is clogged?

When the intercooler becomes clogged (for example, with turbine oil or dust), the engine loses up to 15–20% of power. The turbine begins to operate in extreme mode, which leads to its premature wear. In diesel cars, this can also cause detonation and damage to the pistons.

6. Radiators in hybrid and electric cars

Electric cars and hybrids have unique heat exchangers that are not found in traditional cars:

  • 🔋 Battery radiator — cools lithium-ion batteries (for example, in Tesla Model S or Hyundai Ioniq 5). Overheating the battery will shorten its life and may lead to thermal runaway (uncontrolled fire).
  • ⚡ Inverter radiator - removes heat from the power electronics, which converts direct current from the battery into alternating current for the electric motor.
  • 🔄 Charger heatsink — cools the on-board charger (in models with fast charging support, for example, Porsche Taycan).

In hybrids (for example, Toyota Prius or Ford Escape Hybrid) are often installed combined radiators, where heat exchangers for the engine, automatic transmission and inverter are combined in one housing. This reduces weight and simplifies layout, but complicates leak diagnosis.

7. How to check radiators for malfunctions?

Regular diagnostics of heat exchangers will help avoid costly repairs. Here are the key signs of problems:

Antifreeze or oil leaks under the car|Engine overheating (temperature arrow in the red zone)|Poor interior heating in winter|Extraordinary noise from the cooling fan|Smell of burnt oil or plastic-->

To check it yourself:

  1. Inspect radiators for physical damage (dents, cracks). Even a small crack can lead to leakage.
  2. Check coolant level in the expansion tank - it should be between the marks MIN and MAX.
  3. Assess the condition pipes - they should not be hard or swollen (a sign of aging rubber).
  4. With the engine running, touch the bottom of the main radiator - if it is cold and the top is hot, then heat exchanger clogged or the thermostat is not working.
⚠️ Attention: Never open the expansion tank cap on a hot engine! The pressure in the system can reach 1.5–2 atm, and boiling antifreeze will burst out, causing burns. Wait 20-30 minutes for the motor to cool down.

The number of heat exchangers depends on the type of engine, gearbox and the presence of additional systems. The table below provides a comparative overview for different classes of cars:

Vehicle type Number of radiators List of heat exchangers Examples of models
Budget petrol car (manual transmission) 2–3 Main radiator, heater radiator, sometimes oil cooler Lada Granta, Kia Picanto
Petrol car with automatic transmission 3–4 Main, heater, automatic transmission, sometimes oil Toyota Camry, Honda CR-V
Diesel car with turbine 4–6 Main, heater, automatic transmission, intercooler, oil, EGR cooler Volkswagen Passat TDI, BMW 530d
Hybrid 5–7 Main, heater, automatic transmission, battery, inverter, charger Toyota RAV4 Hybrid, Ford Kuga PHEV
Electric car 3–5 Battery, inverter, charger, stove (electric) Tesla Model 3, Nissan Ariya
💡

The more modern and technologically advanced the car, the more radiators it has. For example, in Tesla Model S there can be up to 5–6 of them, whereas in the old VAZ-2110 - only 2.

FAQ: Frequently asked questions about radiators in cars

Is it possible to drive with a current radiator?

Short-term - yes, but only if the leak is small and you constantly add antifreeze. However, ignoring the problem for a long time will lead to engine overheating, deformation of the cylinder head or even jamming of the engine. On average, repairs after this cost 50,000–150,000 rubles.

How often should radiators be flushed?

It is recommended to flush the cooling system every 2–3 years or when replacing antifreeze (every 60,000–100,000 km). For washing, use special compounds (for example, HI-GEAR Radiator Flush) or distilled water with citric acid (to remove scale).

Why does the cooling fan run constantly?

This is a symptom of one of the problems:

  • Defective temperature sensor (gives a false signal to turn on)
  • Radiator clogged (poor heat transfer)
  • The thermostat is broken (antifreeze circulates only in a small circle)
  • The fan control unit has failed

It is better to carry out diagnostics at a service station with a computer check.

Is it possible to repair the radiator or only replace it?

Minor damage (cracks, breakdowns) can be welded with argon or soldered (for copper radiators). However, modern aluminum radiators are often not subject to high-quality repairs - they are replaced. Average cost of a new radiator:

  • Budget cars: 3,000–8,000 RUR
  • Middle class: 10,000–20,000 RUR
  • Premium and sports cars: RUB 30,000–100,000
What to do if the radiator is clogged from the outside?

Clean it with compressed air (pressure no more than 3-4 bar) or a soft brush. Do not use water under pressure - this can bend the honeycomb. For severe contamination (for example, after off-road driving), you will have to remove the radiator and wash it outside with special means (for example, K2 Radiator Cleaner).