Vehicle makes a hissing noise around 1500 rpm when accelerating. Noise comes and goes. Only sounds while driving not while idiling.
My car has 68000 miles.
My car has an automatic transmission.
This may be a sign of a vacuum leak. High idle speed, stalling and hissing sounds are common signs of a vacuum leak. When a vacuum leak is present in an engine, this causes an excessive imbalance in the air/fuel ratio which creates a loss of power and causes the motor to run at a much higher RPM as a result of the increased oxygen present in the fuel charge being injected into the motor. I would recommend having an expert from YourMechanic come to your location to diagnose your vacuum leak as these can be very difficult and time consuming to trace.
Have a car question? Get free advice from our top-rated mechanics.