LR
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CoolingHigh severity

Overheating from a blocked or tired radiator

Safety or reliability risk. Fix promptly.

Symptoms

Rising temperature on hills or long runs, cold patches on the radiator, coolant boiling over.

Likely cause

Scale and old coolant block the radiator tubes, and mud blocks the fins from the outside.

Suggested fixes

Listed roughly in the order most owners try them.

  1. 1

    Flush the cooling system

    Back-flush the radiator and block, then refill with the correct antifreeze at a 50 percent mix.

    Difficulty:
    Easy DIY
    Cost:
    £ (Under about £50 in parts)
  2. 2

    Clean the radiator fins

    Hose mud out from the engine side outwards with gentle water pressure.

    Difficulty:
    Easy DIY
    Cost:
    £ (Under about £50 in parts)
  3. 3

    Fit a new or re-cored radiator

    If flushing does not help, the core is blocked inside. A new radiator is the reliable fix.

    Difficulty:
    Moderate DIY
    Cost:
    ££ (About £50 to £300)

This is general guidance gathered from owner experience and workshop practice, not a substitute for a workshop manual or a qualified mechanic. Costs are rough parts-only guides. Brakes, steering and suspension work affects safety, so if in doubt have it checked professionally.

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