Low Whistle when hot.

Richard Lorand Aug 6, 2019

  1. Richard Lorand

    Richard Lorand New Member I am in great_britain

    17
    7
    3
    Map
    Could anybody suggest the source of this whistle. It usually occurs when I slow down after a long run down the motorway of after it has been stopped and started. Its a Colorado 1998 KZJ95 that had 109k on the clock two years ago and now had 130k and has always had this problem. It does not do it on tick over and is usually between 1 and two thousand revs but at a constant pitch it is not engine rev related. It very rarely does it when stood still but appears to be round the fan area. If it was the fan, pullies, alternator or water pump the sound would alter with engine revs but it doesn't. It almost sounds like air intake whistle but is from the wrong area. I would like to get it sorted before I ship it to Canada next year for a grand tour. Anybody have any suggestions.
     
  2. AdventureWagon

    AdventureWagon New Member I am in australia

    35
    2
    8
    Map
    Sure it's not the vicious fan clutch? Should feel resistance if you spin by hand when engine off, and it should stop in 1 revolution.

    Auto or manual trans?
     
  3. Richard Lorand

    Richard Lorand New Member I am in great_britain

    17
    7
    3
    Map
  4. Shayne

    Shayne Well-Known Member Guru

    11,417
    3,625
    113
    Map
    Between 1 and 2000rpm your turbo is winding up , you sure thats not what your hearing ?

    Took me so long to find a whisle that did not sound healthy i eventually pulled over on a motorway a couple of hundred miles away from home and on my way to Romania because i thought my turbo was going to explode .

    It was the crankcase breather pipe which had obviously split long before in a minor way and undiscovered finally made a horrendous noise when it split properly , though not so bad i couldn't salvage it by chopping a bit off the end and taping it up to refit and continue on the trip .
     
  5. Richard Lorand

    Richard Lorand New Member I am in great_britain

    17
    7
    3
    Map
    Just to mention no over heating and air con works fine.
     
  6. Richard Lorand

    Richard Lorand New Member I am in great_britain

    17
    7
    3
    Map
    Would I not hear the turbo when cold as well. I only get the whistle when engine very hot.
     
  7. Shayne

    Shayne Well-Known Member Guru

    11,417
    3,625
    113
    Map
    Could be belt squeal
     
  8. diggerdave

    diggerdave Well-Known Member

    455
    245
    43
    Spring stretch mod?
     
  9. Richard Lorand

    Richard Lorand New Member I am in great_britain

    17
    7
    3
    Map
    No spring stretch mod.
     
  10. diggerdave

    diggerdave Well-Known Member

    455
    245
    43
    Have a look via the search function... a spring in the fuel supply can cause a whistling noise in the fuel supply line that's most prominent in the passenger footwell. A VERY simple fix that's worth a try, in case it's never been done. (If I remember right a guy in South Africa discovered it 20 years ago. Most have been done though.)
     
  11. Richard Lorand

    Richard Lorand New Member I am in great_britain

    17
    7
    3
    Map
    Many thanks for all your suggestions. Maybe the vicious fan clutch needs a closer inspection. AdventureWagon suggests that when you spin the fan it should stop in on revolution. When I spin mine it stops dead after I let go. Is this good or bad. As stated previously there is no over heating, which is usually a symptom of vicious fan failing.
     
Don't like the adverts? Become a supporter

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice