Car Repair Questions Diagrams Auto Manuals Auto Repair Estimates Automotive Repair Diagnostic Trouble Codes

A radiator is a type of heat exchanger. It is designed to transfer heat from the hot coolant that flows through it to the air blown through it by the fan.

Most modern cars use aluminum radiators. These radiators are made by brazing thin aluminum fins to flattened aluminum tubes. The coolant flows from the inlet to the outlet through many tubes mounted in a parallel arrangement. The fins conduct the heat from the tubes and transfer it to the air flowing through the radiator.


Radiator

The tubes sometimes have a type of fin inserted into them called a turbulator, which increases the turbulence of the fluid flowing through the tubes. If the fluid flowed very smoothly through the tubes, only the fluid actually touching the tubes would be cooled directly. The amount of heat transferred to the tubes from the fluid running through them depends on the difference in temperature between the tube and the fluid touching it. So if the fluid that is in contact with the tube cools down quickly, less heat will be transferred. By creating turbulence inside the tube, all of the fluid mixes together, keeping the temperature of the fluid touching the tubes up so that more heat can be extracted, and all of the fluid inside the tube is used effectively.

Radiator
Picture of radiator showing side tank with cooler

Radiators usually have a tank on each side, and inside the tank is a transmission cooler. In the picture above, you can see the inlet and outlet where the oil from the transmission enters the cooler. The transmission cooler is like a radiator within a radiator, except instead of exchanging heat with the air, the oil exchanges heat with the coolant in the radiator.

> How to Flush a Radiator

Cooling Syatem Flow Chart

Cooling System Flow
On cars with automatic transmissions, there is normally also a separate circuit for cooling the transmission fluid built into the radiator. The oil from the transmission is pumped by the transmission through a second heat exchanger inside the radiator.

divider
Top Categories

Serpentine Belt Routing Diagrams
Ask a Mechanic
Free Insurance Quotes
Car Owners Manuals
Auto Wiring Diagrams
Auto Repair Manuals
Auto Repair Estimates
Hybrid Cars
Nut & Bolt Measuring Charts
Mechanic's Lien Form

Manufacturer

Acura
Audi
BMW
Buick
Cadillac
Chevy
Chrysler
Datsun
Dodge
Ford
GEO
GMC


Honda
Hyundai
Infiniti
Isuzu
Jaguar
Jeep
Kia
Lexus
Lincoln
Mazda
Mercedes
Mercury


Mitsubishi
Nissan
Oldsmobile
Plymouth
Pontiac
SAAB
Saturn
Scion
Subaru
Suzuki
Toyota
VW
Top Repair

Air Conditioning Troubleshooting
Blown Head Gasket
Brakes
Auto Repair
Engine Overheating
Engine Sensors
Struts
Hub Bearings
No Start Diagnostics
Transmission