1. Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

strange sound

Discussion in 'XJ Technical Chat' started by dirticops, Mar 23, 2012.

  1. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    When I start my bike and let it idle I get a strange noise from the motor. It sounds like a bird chirping, any ideas?
     
  2. splazoid

    splazoid Member

    Messages:
    149
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    WI, USA
    Are thevalves in spec? If they are, there will still be some slight noise, but if they are not, there could be all kinds of strange sounds.

    Where is the sound coming from? Top of the engine, bottom of the engine, etc?
     
  3. Bobe7316

    Bobe7316 Member

    Messages:
    132
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Tasmania Australia
    I had a noise like this and could not find it for weeks. It sounded like a small
    squeak like squeak squeak squeak. It turned out that the number 4 carb intake rubber had come loose where it bolts onto the engine allowing a small
    amount of air to get in on every intake stroke. It drove me crazy until I found
    it.

    Bob
     
  4. splazoid

    splazoid Member

    Messages:
    149
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    WI, USA
    Air suction on intake is also a good idea. If you are able, take a video of it and rev up a little bit.
     
  5. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    415
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    Exhaust leak at the head.

    How about you kill off the duplicate thread?
     
  6. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    I will kill the other thread didn't see it posted twice, don't cry fitz.
     
  7. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    Oh an thanks sounds like it is on the intake side
     
  8. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    415
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    Do the "unlit propane torch" trick to probe for vacuum leaks; if it's on the intake side that'll locate it for you.
     
  9. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    Good iea wil do, I think it. Might be an untightened spark plug but I will check with a torch too. Thanks. Just rode it to dam its aweesome. I willpost a new thread tnight with pics
     
  10. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    415
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    Don't be riding it until you find and fix the sound; if it's an intake leak you could hole a piston.
     
  11. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    It sounds like it is eminating from the upper left of the motor, it is loud enough that i can hear it over the cut off headers. Motor runs great minus the massive chirping bird living in the top of my motor :)
     
  12. yamamann

    yamamann Member

    Messages:
    164
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    Barrie, Ontario, C A N A D A
    looks like you msy hsve the problem figured out based on our usual resident experts - boy I learn so much from visiting here thanks - for what it is worth, I often use the screwdriver method of tracing odd noises - with the engine running place the tip of a long screwdriver on the area where it seems to be coming from - put your ear up to the opposite or handle end moving the tip from place to place listening until the noise gets louder - thanks again for the great advise - drive carefully everyone
     
  13. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    Is there a chance that the sound coud be coming from a bad cylinder head gasket. I was reading my manul and it stated that a blow by at the head gasket can make aloud chirping noise. Has anyone experienced this?
     
  14. splazoid

    splazoid Member

    Messages:
    149
    Likes Received:
    0
    Trophy Points:
    16
    Location:
    WI, USA
    A blown head gasket definitely might cause a sort of puffing sound. Do you have acompression tester? Performing this test is a pretty basic indicator that will help getting to know your engine better, and is done periodically for maintenance.

    Your manual should also have some instructions on how this is done.
     
  15. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    415
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    BINGO.

    See what numbers it makes. That'll diagnose a head gasket leak and if the numbers are fine, it's probably an exhaust gasket leak.
     
  16. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    Thanks gentlemen onward and upward
     
  17. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    Checked the exhaust and appears to be no leaks, any chance a lower main bearing could be going out and making that much noise.
     
  18. oilheadron

    oilheadron Member

    Messages:
    121
    Likes Received:
    1
    Trophy Points:
    18
    Location:
    Athens, AL
    Slightly out on a limb here: Get a mechanic's stethoscope (or a long screwdriver) and try to isolate the source of the noise. If it's near the topend, I'd pull the valve cover off immediately and look for signs of oil starvation.
     
  19. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    415
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    Did you do a compression test? To test for a head gasket issue?

    How did a chirping sound from the top of the motor become a main bearing "going out?" (HIGHLY UNLIKELY)

    "Checked the exhaust" did you remove the nuts on each headpipe and have a look at the gaskets? You'll see obvious signs of the blowby if it is exhaust related, but not unless you take it apart and look. You can't see anything just looking from the outside. You CAN sometimes detect an exhaust leak by holding a strip of paper up near the pipe-head junctions and seeing if it gets deflected, but you have to get lucky... true diagnosis will require some disassembly.

    If you had the exhaust head pipes off and didn't replace the gaskets, then a head-pipe leak still gets my vote.
     
  20. dirticops

    dirticops Member

    Messages:
    125
    Likes Received:
    0
    Trophy Points:
    16
    Pulled al head pipes off and they all hace new gasket from chacal. I will prob pull the to off and check the valves next.
     

Share This Page