I recently bought a Tiguan with 9000 miles on it. Whenever I accelerate it makes a hissing sound. It's not like a turbo whistle, since it is turbo 4 cylinder. It sounds like 'ssss' for half a second like it's letting off steam in the air, kind of like a truck sounds. Does this sound serious? Should I take it to the repair garage?
Hello. The sound you are hearing is most likely a vacuum or intake manifold leak. The vacuum created by the engine is crucial for proper intake of fuel and air, as well as the combustion inside of the chamber. Now the intake manifold for that air coming in and being mixed with the fuel can also make a sound if there is a leak. The vacuum is sucking in the air and any hole or gap will likely make noise during that process. You will want to get this looked at. Depending on the severity of the leak, you will most likely see an increase of power. To have this diagnosed, a certified professional, like one from YourMechanic, can come to your car’s location to inspect the sound and let you know what needs to be repaired.