Radiator
What it is
The radiator is the heat exchanger at the front of the car that cools the hot coolant with airflow before it returns to the engine.
What it does
It sheds engine heat to the air. A clogged, leaking or corroded radiator causes overheating, coolant loss and a sweet smell, and plastic end-tanks are a common failure point.
Symptoms of failure
- Overheating, especially in traffic or on hot days
- Coolant leak from the radiator or its tanks
- Low coolant and steam
- Sweet coolant smell
- Sludge or discoloured coolant (internal corrosion)
Which vehicles need it
Every liquid-cooled vehicle. Stone damage and cracked plastic end-tanks are common with age.
Replacement cost
| DIY (part only) | $70–$250 |
|---|---|
| At a shop (parts + labor) | $350–$900 |
| Replacement interval | No fixed interval — replace on leak or blockage; flush coolant on schedule to extend life. |
| DIY difficulty | Moderate (DIY) — hoses, clips and coolant; bolt-in on most cars |
| Recommended brands | Denso, Spectra, Koyorad, OEM |
Where to buy the part
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Recommended products
Tools to diagnose it
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Frequently asked questions
Why does my car overheat only in traffic?
At a standstill the radiator relies on the cooling fan instead of airflow. Overheating in traffic but not at speed points to a clogged radiator, a weak fan, or low coolant.
Can I use stop-leak for a radiator leak?
It can be a temporary get-home fix for a tiny leak, but it can also clog the cooling system and heater core. For a real leak, repair or replace the radiator properly.