Sounds Like a Vacuum Leak, High Pitched Whistle From Engine

Discussion in 'SN95 4.6L Mustang' started by topless98gt, Oct 3, 2007.

  1. topless98gt Adhesive Feces

    Member Since:
    Mar 31, 2005
    Message Count:
    666
    Likes Received:
    0
    Trophy Points:
    0
    I've been experiencing a high pitch whistle from my engine for the past two months or so, but never really thought anything of it. It is really starting to get annoying now. It sounds like it may be a vacuum leak or something, but I figured I'd ask around to see if anyone has ever experienced something similar. It is coming from the engine bay, I think near the middle.

    Thanks for any advice/info in advance!
  2. joshjwc9 Member

    Member Since:
    Jun 13, 2006
    Message Count:
    880
    Likes Received:
    1
    Trophy Points:
    18
    Does it do it all of the time? Or with AC/Heat on? Mine was making a similar sound and it was the AC idler pulley sparking and not engaging right.
  3. Rusty67 Well-Known Member

    Member Since:
    Dec 3, 2002
    Message Count:
    3,342
    Likes Received:
    0
    Trophy Points:
    56
    How many miles on the engine ? Check the PCV valve ?
  4. lvmustanggt New Member

    Member Since:
    Apr 10, 2006
    Message Count:
    750
    Likes Received:
    0
    Trophy Points:
    0
    I do have same problem and don't even know where it's comming from :bang:
    I change everything pcv, iac, egr, alternator, pulleys, gasket with no luck:mad:
  5. scupking Active Member

    Member Since:
    Sep 19, 2005
    Message Count:
    1,198
    Likes Received:
    0
    Trophy Points:
    36
    Mine does the same thing and sounds like a supercharger. Mine is coming from the pullies though.
  6. RedDaemon Advanced Member

    Member Since:
    Mar 31, 2005
    Message Count:
    4,190
    Likes Received:
    0
    Trophy Points:
    66
    when does it happen?
  7. GettinThere New Member

    Member Since:
    Jul 29, 2005
    Message Count:
    563
    Likes Received:
    0
    Trophy Points:
    0
    Do you have an aftermarket plenum and/or throttle body?
  8. lvmustanggt New Member

    Member Since:
    Apr 10, 2006
    Message Count:
    750
    Likes Received:
    0
    Trophy Points:
    0
    mine starts at around 2000 rpm.
  9. tank_567 Member

    Member Since:
    Mar 20, 2007
    Message Count:
    521
    Likes Received:
    3
    Trophy Points:
    18
    it could be the tensioner pulley or the tensioner its self. I did you replace with new?
  10. lvmustanggt New Member

    Member Since:
    Apr 10, 2006
    Message Count:
    750
    Likes Received:
    0
    Trophy Points:
    0
    I did change new tensioner
  11. 2000fordstanggt Member

    Member Since:
    Sep 6, 2005
    Message Count:
    415
    Likes Received:
    0
    Trophy Points:
    16
    my gatorback always made noise..not sure what type of belt you have though
  12. topless98gt Adhesive Feces

    Member Since:
    Mar 31, 2005
    Message Count:
    666
    Likes Received:
    0
    Trophy Points:
    0
    It does it all the time, regardless of A/C position. My A/C compressor is out, though, but it was doing it before that went. It doesn't sound like it's coming from that, but I can check again.

    I can only really hear it at idle because my exhaust is so loud.

    22x,000 miles on the engine. Stock plenum, stock throttle body. I have never changed the belts.

    It was making this sound long before I successfully made the 1500 mile trip to Canada with no problems at all. Yeah, I was surprised too!

    I will check all of the pulleys and the PCV valve (located on the passenger side of a 98 GT, right?).

    I apologize for not being around much. I've been living it up here in Toronto :D
  13. GettinThere New Member

    Member Since:
    Jul 29, 2005
    Message Count:
    563
    Likes Received:
    0
    Trophy Points:
    0
    Maybe there's an air leak around the air box / filter, or around the IAC? :shrug:
  14. topless98gt Adhesive Feces

    Member Since:
    Mar 31, 2005
    Message Count:
    666
    Likes Received:
    0
    Trophy Points:
    0
    Yeah, maybe it's time to clean my K&N. I'll check to see if it alters with that.
  15. Rusty67 Well-Known Member

    Member Since:
    Dec 3, 2002
    Message Count:
    3,342
    Likes Received:
    0
    Trophy Points:
    56
    If you want to see if the manifold has some sort of vaccume leek you can spray carb cleaner around the areas where the manifold/plenum seals and if you hear the engine change RPMs you have a leek there.

Share This Page