My 2003 GMC Envoy LX makes a vacuum noise when i accelerate. It runs but is a loud vacuum kind of noise.
Any idea what it could be ?
Check the intake snorkel from the intake (air filter) box to the throttle body, and be sure everything is tight, in place, and undamaged.
Also, try to isolate the noise source. There have been issues with the Electro-Viscous Fan Clutch producing similar sounds.
More questions? Please include engine size.
It turn out to be the Fan Clutch.