Your car's cooling system routes the coolant from the engine through the radiator. While it's in the radiator, the air coming through the vents will cool it down. Some engines also have a fan to push air through the radiator for more efficient cooling. Once the coolant has flowed through the radiator, it's sent back to the heater core. The closed circuit of the cooling system allows you to fill the radiator and maintain the coolant level unless there's a leak. Here's a look at some of the most common sources of coolant leaks to help you troubleshoot the problem.
Leaking Water Pump
The water pump pushes the coolant between the radiator and the engine. There are several seals in and around the pump that can fail, and when they do, it leads to a coolant leak. Some water pumps are created in two pieces, and those pieces are connected with a gasket. Check the outside of the water pump case for any dampness. If there's any coolant on the outside of the pump, there's a good chance that you have a bad seal on the pump.
Since the radiator is typically placed at the very front of the engine so that it can draw in outside air, it's no surprise that they are also vulnerable to damage from road hazards like rocks and other debris. This damage can lead to leaks. Look through the front of your car to the radiator fins to see if you can see any signs of damage. Open the hood and look between the radiator and the headlight area for any variances in the surface appearance that could indicate damage.
Additionally, if you don't have your radiator flushed on a regular basis, the coolant that settles at the bottom of it can corrode and damage the metal. You might also see some leaks from the areas where the hoses connect. If it's a hose leaking, tighten the clamp first. That may fix it. Otherwise, if the radiator is damaged, you'll need to replace it.
Seeping Heater Core
The heater core is attached to your car's climate control system. Since this means that most of the components are inside the dashboard, it can be hard to pinpoint the heater core as the source of the problem. If you're seeing drips that seem to be coming from the dashboard area, that's an indication that the heater core is seeping coolant. You may need to have an auto mechanic replace the heater core, though, as it can be hard to access.
There are many different places where your engine could be leaking coolant, but these are three of the most common. If you've checked these and you're still unable to identify where the leak is coming from, you may need to have the car put on a lift to check the undercarriage and trace the leak (at a shop like Lakewood Imports Volvo Specialists).