Quick answer
If your temperature gauge goes into the red, pull over and switch off the engine. Don't open the radiator cap while it's hot. The most common causes are low coolant, a stuck thermostat, a dead radiator fan, a failing water pump or a blocked radiator.
Most of these parts cost ₦30,000 to ₦150,000 for common Toyotas. Driving on until the engine is damaged costs far more.
Overheating right now?
- Pull over safely and switch off the engine.
- Don't open the radiator or coolant cap. Hot coolant is under pressure and can burn you badly.
- Wait at least 30 minutes for the engine to cool.
- Check the coolant level once it's cool. Top up if it's low, and look for leaks under the car.
- Don't keep driving with the gauge in the red. It can warp the cylinder head and blow the head gasket.
Common causes and what the parts cost
| Cause | Part price (common Toyotas) |
|---|---|
| Low coolant or a leak: Toyota coolant, 4 to 5 litres | ₦30,000 – ₦45,000 |
| Thermostat stuck closed | ₦30,000 – ₦50,000 |
| Water pump, older engines (e.g. Corolla 1ZZ, Camry 2AR) | ₦20,000 – ₦26,000 |
| Water pump, newer electric type (e.g. Camry 2018, Corolla 2020) | ₦110,000 – ₦150,000 |
| Radiator, Toyota Corolla 2005 to 2014 | ₦55,000 – ₦95,000 |
| Radiator with fan, Toyota RAV4 or Corolla | ₦80,000 – ₦150,000 |
A radiator fan that won't spin isn't always the fan. A blown fuse or a bad relay costs far less, so ask for those to be checked first.
How to tell which one it is
- Overheats in traffic but fine on the open road: often the radiator fan.
- Overheats quickly after starting, top hose stays cold: often a stuck thermostat.
- Coolant keeps disappearing, puddle under the car: a leak from a hose, the radiator or the water pump.
- Coolant disappears with no puddle, white smoke, milky oil: possibly a head gasket. Stop driving and get it checked.
Coolant, not water
Plain water works in an emergency, but it boils at a lower temperature than coolant and lets rust build up inside the engine. Once you're home, drain it and refill with the right coolant for your car.
Questions drivers ask
Can I drive an overheating car to the mechanic?
Only if the gauge has come back to normal after cooling and the coolant is topped up, and only a short distance. If it climbs into the red again, stop. Towing costs less than a new engine.
How much does it cost to fix an overheating car in Nigeria?
It depends on the cause. Coolant is about ₦30,000 to ₦45,000, a thermostat ₦30,000 to ₦50,000, a Corolla radiator ₦55,000 to ₦95,000, and a water pump ₦20,000 to ₦150,000 depending on the engine. Labour is extra.
Why does my car overheat in traffic?
In traffic there's no air rushing through the radiator, so the electric fan has to do the work. If it's not switching on, the car overheats when stopped and cools down once you move.
Can I use water instead of coolant?
In an emergency, yes. Replace it with proper coolant soon, because water boils sooner and causes rust inside the cooling system.