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Will 9/19/2012
1999 GMC Sierra 2500 SLE 8 Cyl 6.0L - Engine
What would cause a whistling sound under acceleration?
Engine makes whistling sound when I accelerate or push on gas when in park. Does not do it when cold. No warning lights are on. It started a couple of weeks ago when pulling a trailer.
1 Answer
  • HouseCallAuto
    HouseCallAuto 9/19/2012
    Vacuum leak. there is no substitute for you listening and locating the origin of the noise with your ears while making the noise happen over and over. You will have to climb up there and get close to the top of the engine with it running, carefully obviously. You can manually move the throttle and listen and look.
    Will 9/20/2012
    Thanks, I'm sure you are right. I have a neighbor who is a GM mechanic and he drove it yesterday and said the same thing. He is taking it to work with him today to pinpoint the source of the leak...hope it doesn't cost too much.
    HouseCallAuto 9/20/2012
    I'm gonna say intake manifold gasket

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