Q: Car still overheating, and hissing, even after changing the coolant.

asked by on December 29, 2015

My coolant service light went off, so I went directly to the dealer to buy coolant. After changing the coolant the coolant service light went off again. I opened the hood and heard hissing noises. I believe it is a hose, but I can't determine which one.

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Hi there. Some coolant leaks can be hard to find and may only appear when the system is under pressure. If you are getting a hissing noise it is possible that you have a leaking hose, but most of the time on this model VW it is caused by a leak in the radiator or the water pump. If the leak is not visible by looking around the engine compartment then it would be best to consult the help of a certified mechanic, like one from YourMechanic, that has a cooling system pressure tester. With this tool they can pressurize the cooling system in order to more easily identify the source of the leak.

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