chirping noise from engine under load

Discussion in 'Chevy C/K Truck Forum' started by jveiga81, May 24, 2013.

  1. jveiga81

    jveiga81 New Member

    91 gmc sierra with 305
    When I put the truck into gear I hear a faint chirping sound and when I accelerate a little it gets pretty loud.
    In park or neutral the noise is really faint but doesnt get louder as I accelerate it has to be in gear. It is loud with a little acceleration and gets quieter with more acceleration. The noise is coming from the front near the crank pulley. I started it without the serpentine belt and it still makes the noise. Thanks for any help!
    Last edited: May 24, 2013
  2. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Can you get a good look at the pulley to see if its loose or possibly got a crack on the mounting face?
  3. jveiga81

    jveiga81 New Member

    I looked at the pulley I dont see any cracks and the pulley is not loose at all. I will take a video and post it up on Monday. Thanks
  4. K15 Blazer Guy

    K15 Blazer Guy Member 2 Years 100 Posts

    weird... no belt on the truck, but the pulley churps....
    try unscrewing your trucks radio antenna, and using it as a touch stethoscope on/near the timming pulley...
    you may have a spun bearing or something, but listen for it, and you may be able to find out exactly what/where it is.
    not seeing-hearing there myself, im pretty stumped...
  5. jveiga81

    jveiga81 New Member

    I used a stethoscope and its really loud by the back of the engine near the catalytic converter. I thought it was the crank pulley but its very faint at the front. its more noticeable near the cat. I had the tranny inspected and the exhaust was replace from the cat back and they said my manifolds and y-pipe were fine. It looks like a hole in the y-pipe on the video but its just rust and I have no idea why there is red silicone around the clamp but the garage said it was fine. Here is a youtube link for my video
  6. jveiga81

    jveiga81 New Member

    I used a stethoscope and its really loud by the catalytic converter. I had the tranny inspected and they said it has nothing to do with the tranny. I had the exhaust checked and they put a new cat on and said my y-pipe and manifolds were fine. Here is a youtube clip of the noise
  7. K15 Blazer Guy

    K15 Blazer Guy Member 2 Years 100 Posts

    well, yeah it would be loud there....
    thats weird... just keep looking for it with the stethoscope. youll find it eventually.
    im pretty sure my pilot bushing is shot... it does a sort of groan at each start up, only at start up. but i have a stick shift
  8. marksoldtowne

    marksoldtowne Member 1 Year

    *Belts can be noisy, Fan belt, or power off belts that drive steering pump, air con make. *if you press the accelerator a bit, *you get to a steady rpm, the noise would return.While you are checking the belt and idler pulley, - don't forget to check the alternator too. If you get a long screwdriver, or even a small diameter stick of wood, and put it against alternator housing (both front and rear ends) which helps to reduce noise

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