Hiss sound that happens after I shift?

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  • MC Hammered
    R3VLimited
    • Jul 2008
    • 2076
    #1

    Hiss sound that happens after I shift?

    In first 3 gears, after I let off the throttle I hear this hiss similar to a wastegate blowing in a turbo car.

    At first I thought it was due to the cracked ICV hose causing a vacuum leak. I replaced the hose last night and the hiss is still there.

    The car idles fine, drives fine, but I get this faint hiss after normal acceleration and shifting. Hiss is a bit louder is I shift after hard acceleration.

    I tried searching for info and found that this may be a normal sound for exhaust setups that aren't running cats. Any truth to this?

    TIA for any information.


    My 1989 e30 s52 Touring... this is Betty

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    Tags: None
    • f4tj0n
      E30 Addict
      • May 2013
      • 411
      #2
      I have a slight hiss as well.. I KNOW that one of my 2.5" V-Bands got warped when we welded it up and there is a slight leak there.. I'm thinking of running a "v-band gasket" but I havent gotten around to it.

      My car also has no cats.

        Comment

        • dude8383
          Forum Sponsor
          • Jan 2005
          • 10387
          #3
          yeh it could be a slight exhaust leak...
          IG: deniso_nsi Leave me feedback here

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            • raj
              Advanced Member
              • Oct 2013
              • 100
              #4
              I have this also. It is intermittent. I have no exhaust leaks and a catalytic converter.

                Comment

                • HerbE30
                  E30 Addict
                  • Nov 2015
                  • 538
                  #5
                  Check your CCV. The m54 I thrash has a bad one and it makes a hissing noise?

                  Are you drinking oil like its wine?
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                  Morty: Well Summer maybe people that create things aren’t concerned with your delicate sensibilities you know? Maybe the species that communicate with each other through a filter of your comfort are less evolved that the ones that just communicate? Maybe your problems are your own to deal with and maybe the public giving a shit about your feelings is a one way ticket to extinction.

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