Radiator Guide
Last updated: 24 April 2026
The radiator dissipates heat from the engine coolant to the atmosphere, preventing overheating. Modern radiators use aluminium cores with plastic end tanks for lightweight efficiency. Leaks, internal blockage, and physical damage from road debris are the most common failure modes. A failing radiator causes overheating, which can lead to head gasket failure and catastrophic engine damage if not addressed.
Signs your radiator needs replacing
Radiators don't have a fixed service interval — they fail from corrosion, impact damage, or age-related degradation of the plastic end tanks.
- Coolant leak visible as green, pink, or orange puddles under the front of the car
- Engine temperature rising above normal, especially in traffic or on hot days
- White crystalline residue around radiator seams or hose connections
- Discoloured or contaminated coolant (brown, milky, or oily appearance)
- Bent or damaged fins reducing airflow through the radiator core
Radiator types and replacement tips
Replacement radiators are available in OE-specification and aftermarket options. Ensure the core dimensions, hose positions, and mounting points match your vehicle.
- Aluminium/plastic radiators are standard on most modern vehicles
- Full-aluminium radiators offer better heat rejection for performance applications
- Check if your vehicle has an automatic transmission oil cooler built into the radiator
- Flush the cooling system before fitting a new radiator to remove debris
- Replace the radiator cap — a weak cap reduces system pressure and cooling efficiency
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Signs of a leaking radiator, repair vs replacement, and how to prevent overheating.
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Frequently Asked Questions
How do I know if my radiator is leaking?
Low coolant level, puddles under the car (green, pink, or orange fluid), overheating, and white residue around radiator seams are common signs.
Can a radiator be repaired?
Small leaks can sometimes be temporarily patched, but replacement is the reliable long-term fix. Modern aluminium/plastic radiators are not cost-effective to repair.
When should I replace my radiator?
Radiators don't have a fixed replacement interval. Replace when you see leaks, internal blockage (uneven heating), or physical damage from road debris.
How much does radiator replacement cost?
The price of a radiator depends on your exact vehicle and the brand you choose. Enter your registration above to see parts confirmed to fit, then compare prices from the brands we stock on this page. Free UK delivery on orders over £99.
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