Radiator

Dissipates heat from engine coolant by passing it through thin tubes with fins, where ambient air (and the radiator fan) cool the fluid before it recirculates through the engine.

$300 – $900

Total Cost

As needed (typically 100,000+ miles)

Replace Interval

Moderate

DIY Difficulty

Fix Within a Week

If It Fails

Overview

The radiator is the main heat exchanger in your cooling system. Hot coolant from the engine flows through the radiator, where airflow cools it before it returns to the engine. A failing radiator can lead to engine overheating and catastrophic damage.

Parts Cost

$100 – $350

Labor Cost

$150 – $500

Failure Symptoms

Engine overheating

Critical

Coolant leak under the front of the vehicle

High

Coolant level constantly dropping

Moderate

Visible damage or corrosion on radiator

Moderate

Transmission fluid in coolant (radiator with internal trans cooler)

Critical

Green, orange, or pink fluid pooling under car

Moderate

Warning Signs to Watch

Coolant puddles under the front of the car
Temperature gauge running higher than normal
Coolant level drops between services
Visible corrosion or damage on radiator fins

Common Causes of Failure

1Corrosion from neglected coolant (not flushing on schedule)
2Physical damage from road debris or accidents
3Plastic end tank cracking (very common)
4Internal clogging from old coolant or stop-leak products
5Electrolysis from improper grounding

Prevention Tips

Flush and replace coolant at the manufacturer's recommended interval
Use the correct coolant type for your vehicle
Inspect the radiator for leaks and damage at every service
Avoid using stop-leak products — they can clog the radiator and heater core

When to Replace

Replace if leaking, cracked, or internally clogged. Don't wait — a $300 radiator protects a $5,000+ engine from overheating damage.

Radiator by Make

Honda

Honda radiators with internal transmission coolers are known for the transmission cooler failing internally, mixing transmission fluid with coolant and vice versa. This can destroy the transmission. Check coolant color regularly.

BMW

Mercedes-Benz

German car radiators use plastic end tanks that become brittle with age. They typically crack around 80,000-100,000 miles. OEM or quality aftermarket (Nissens, Behr) recommended.

Toyota

Toyota radiators are very reliable and affordable. Quality aftermarket radiators cost $80-$150 and last 100,000+ miles.