Antifreeze leaks are not only messy, but if they are not fixed you can do some serious damage to your engine due to overheating.
A couple of possible sources of leaks on the engine are intake manifold gaskets on the top of some V6 and V8 engines and the head gasket that separates the upper part of the engine from the lower part of the engine.
As you can imagine, it costs a lot of money to fix a head gasket leak because the mechanic is going to have to remove the head off the top of the engine, which will take a lot of labor hours. A repair like this can easily cost between $1,000 and $2,000.
Another common source of a leak is the radiator. Leaks can form on several different places on the radiator, from cracks in the tanks to tubes that leak due to damage or corrosion. Average cost to replace a radiator is $400 to $600.
Radiator caps can fail and leak, but that’s definitely a do-it-yourself repair. Wait until the engine cools down and replace the cap for about $10.
Rubber hoses can be the source of leaks because they are subject to high temperatures and movement every time the engine is running. Be aware that a small leak today could lead to a hose bursting and a breakdown tomorrow. This type of repair is usually in the $50 to $200 range, depending on the number of hoses that need to be replaced.
Heater cores are inside of your dash and they look like tiny radiators. Hot antifreeze flows through them to warm up the interior of your vehicle. If these leak you will probably have antifreeze on the carpet inside of your vehicle and the inside of the windows will fog over with antifreeze.
In some cases, the dash has to come out to replace the heater core, but other times they can be removed from under the hood without too much trouble. Cost to do a heater core can range from $200 to over $1,000 if the dash needs to be removed.
Water pumps can also be the source of a leak when they are worn out. Many times the water pump is behind the timing belt on newer vehicles, so it can be pricey to replace because of the additional labor. Average cost to replace a water pump can range from $200 if it’s easily accessible, to over $600 if it’s behind the timing belt.
Finding small antifreeze leaks can be tricky, but there are products out there such as dyes that can be added to the antifreeze to help spot the leak. After the engine is run for a period of time, the dye (and the leak) will show up when a special UV light is used by the mechanic to inspect the cooling system parts. This allows the mechanic to pinpoint the source of the leak and give you a detailed estimate for the cost of repairs.