What does a car radiator do?
A car radiator disperses heat away from the main engine block. A car engine works by burning fuel (whether petrol or diesel), and this generates a considerable amount of heat. In addition, a car engine has many moving parts; this movement creates friction, which in turn adds to the heat.
Because a car engine must remain not too hot in order to avoid overheating and seizure, when it reaches a certain temperature the thermostat opens to allow the flow of coolant and water around the engine and back to the radiator, where it loses heat to the cooler surrounding air. The front grill of the car allows outside air to blow over the radiator. If the radiator gets too hot, for example on a very hot day, or when the car is stationary, a fan behind the radiator starts, helping to blow air over it.
The most common reason for needing a car radiator repair is a leak. There are many seals, gaskets and hoses in the cooling system that can deteriorate or get a hole in them. Furthermore, every radiator needs to be properly maintained and the coolant must be kept topped up. Your garage should provide coolant changes at the same time as your annual service.
It’s also a good idea to check your car’s coolant level regularly. If it seems to be dropping a lot, then you may have a leak in the cooling system.
What could the problem be with my car radiator?
If your vehicle is hotter than normal, you should check the car radiator and hoses. Unfasten the radiator cap (take care it’s cool enough to touch!) and check the water level in the radiator, topping it up with a coolant or water if necessary. Don’t forget to replace the cap afterwards. Your engine’s cooling system relies on coolant to circulate and remove heat from the engine, therefore the most common cause for an engine overheating is simply a low coolant level.
The radiator should be checked for any leaks, which are the usual cause of radiator failure. However, if no leaks can be found the radiator will need pressure testing by a garage to find the fault.
If the radiator fluid is rusty you need to get your car to a garage soon. This is particularly likely if your car has more than 50,000 miles on it, and it’s a sign that your radiator is becoming gummed up. The radiator will need to be completely flushed out and the coolant changed, and the cooling system must then be bled to remove any air pockets. This is a job for a skilled mechanic.
Some car models have a fan to assist the radiator and cooling system. The electric fan draws cooler air through your radiator when your car isn’t going fast enough to draw it through from the front of the car. If your fan is faulty or not coming on, this in turn can cause your engine to overheat.
Although it’s a more old-fashioned system, there are still lots of cars on the road which have a fan belt to drive the engine cooling fan, rather than an electric fan. Fan belts will wear out over time and can snap, which in turn means the radiator won’t be kept cool and the vehicle’s temperature will start to rise.
Another problem site for a car radiator is the hoses. If the top hose on the radiator is hot but the bottom one is cold, this is a symptom of a failed thermostat. Your engine may be able to stay cool at low speeds because it’s not working that hard, and therefore not creating as much heat. But at high speeds your engine needs lots of coolant flowing through. If the thermostat doesn’t open, there isn’t enough flow to keep things cool.
