The radiator is a critical part of any water-cooled engine. It serves as the heat exchanger between the engine and the environment. It works by cooling the water that has been heated while circulating in the engine’s water jacket. The cooling fan blows cool air through the radiator airways, thereby cooling the water inside the radiator’s water tubes.
Automotive Cooling System
If the cooling system fails, overheating of the engine occurs. Overheating is a risky thing because the engine is designed to operate at a preset optimum temperature. If the engine goes beyond this temperature, it can break down. If overheating goes on for too long, there could be more permanent damage which would require major repairs to be undertaken. Such damage includes the burn out of the cylinder head gasket or complete engine seizure.
Owners of Audis and VWs have often noted a problem with their cars whereby the upper hosepipe is hot while the lower one is cold. It usually happens when the fan is working okay. The upper hosepipe is usually hot, since it is the one that takes hot water from the engine to the radiator for cooling. The lower hosepipe takes the cooled water back into the engine and the cycle is repeated.
When an overheating vehicle is brought into the shop, the technician will first check if there is adequate coolant in the radiator. If coolant level is not the problem, he will detach the upper and lower hoses and run water through the radiator. This will enable him to establish if the cooling tubes in the radiator are blocked. If he finds them blocked, he will unblock them.
Apart from blockages and leakages, other causes of overheating include a malfunctioning thermostat or a failed water pump. The thermostat is usually located at the point where the upper hosepipe joins the engine block. It is designed to allow the engine to warm up to the optimum temperature before it lets the coolant circulate through the radiator. It however tends to fail especially during hot summers.
The water pump is often mounted on the engine block where the lower hosepipe meets the engine block. The water pump is solely responsible for circulating coolant throughout the cooling system. Its failure therefore means that the hot coolant in the engine does not get to reach the radiator for cooling.
If you drive and Audi or VW, be aware that overheating radiators have been known to cause problems. If you suspect your car is at risk, take it to Desert Oasis Auto Repair for service in Las Vegas, NV.