The symptoms of a carburetor vacuum leak, which is the same as an engine vacuum leak, include a hissing sound, an illuminated check engine light and poor acceleration. This condition also causes loss of power, low fuel economy and engine damage.
A vacuum leak from the engine to the carburetor isn't easy to fix, even though symptoms appear. This leak occurs when the line from the engine to the carburetor becomes faulty, which may occur with age. Car owners should pay attention to the check engine light, since it helps to uncover whether a vacuum leak is the issue. If a vehicle is having trouble with idling or stalling, it is best to take the car to an auto mechanic.
When visiting a mechanic, it is necessary to run a diagnosis of the vehicle. In many cases, the mechanic sends smoke through the engine to find out where the leak appears. A mechanic may also use an OBD-II diagnostic test and read the codes, which are P0171 or P0174 for an engine vacuum leak. On average, this diagnostic test runs from about $90 to $110, as of 2015. It is possible to fix an engine vacuum leak at home, but only by someone familiar with vehicle mechanics.