1991 2500 hd 4wd

Discussion in 'GM Powertrain' started by grip9010, Nov 7, 2010.

  1. grip9010

    grip9010 New Member

    Hi guys im new to the site, my first chevy...I bought this truck three weeks ago for 1500 great deal it has a 454 that runs strong however it has a heavy whining noise comming from the engine the previous owner told me it was the power steering pump and i noticed it was leaking so i replaced the pump and the same thing a very loud heavy whining. So i thought mabye one of the pulies so to check everything at once i pulled the surp. belt and started the motor and the same thing (whining).It sounds just like a power steering pump going, but louder.The whining gets louder with increse in rpms, In Park or drive I cant figure out what it could be.I think its internal. Also on the heads theirs a decal that says 454 by Tonawanda engine. Im told these engines have a bit more hp due to a roller valve train but not sure any help please!!!!!!
  2. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    Did you bleed the pump properly when you installed it? you have to crank the wheels back and fourth while someone keeps on an eye on the fluid level since the air in the system doesnt really get pushed out fast enough. Also is there a chance it has a pete jackson gear drive instead of a timing chain??
  3. Sam_A

    Sam_A Rockstar 100 Posts

    Welcome to the club!
  4. grip9010

    grip9010 New Member

    Yes, i thought when i first bought the truck it was the pump, its not the pump i removed the surpentine belt and cranked the motor and it still whining the exact same amount i checked the starter to make sure it not getting stuck and i checked the harmonic balancer, nothing wrong with them i think its internal what would make a heavy (powersteering tipe whin) coming from the top end ? It increase's with rpms in gear or not. ...any clue or advice would be great guys thank you...
  5. chevybulldog6

    chevybulldog6 Rockstar ROTM Winner 100 Posts

    Welcome to the club. I wish I had some advice for you but I am at a loss at the moment.
  6. stephan

    stephan Rockstar 4 Years 5000 Posts

    Hey Grip, welcome to the GM truck club. I think there's a good chance Murdog has your answer with the gear drive. Take your belt off again & listen at the front cover. Use a short piece of garden hose, or a transmission funnel up to your ear. There really isn't anything at the "top" of the engine that could cause a "whine" but a gear drive sure will. Gear drives are a popular add on, for DIY'ers.
    It could also be the camshaft is walking foreward & the cam sprocket could be rubbing on the front cover if it has the stock single row cam chain/sprockets. Try & determine " if " the noise is coming from the front cover. If it is, it is either really good news "gear drive" or if it is the cam walking you can cure it easily with a Cloyes true roller, double row cam chain & sprockets & a front cam button.
  7. grip9010

    grip9010 New Member

    Thanks guys im glad to be here...... I think im gonna pull the engine saturday and just rebuild it she has 200,000 on her, so it may be a good idea. Ill let you guys know sat what that whining is....Thanks again....
  8. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    Sounds good, and that is one way to be sure you dont have any problems. Good luck with it.
  9. grip9010

    grip9010 New Member

    It was the gear drive guys thanks for the advice im swaoping back to chain....
  10. stephan

    stephan Rockstar 4 Years 5000 Posts

    NOOOOOOOOOOOOOOO!! You're not going to take out a perfectly good gear drive & put in a stock chain & sprockets are you?? They're suppose to make that noise. You know that right??

    **edit Hey Grip, you need to get a "grip". That gear drive is a LOT more accurate than a chain & sprockets. You should consider leaving it on there.

    "The whine of a gear drive cam, the louder whine of the old GM rock crusher 4 speed, plus a loud exhaust, & you could just screw the crappy music from the stereo as far as Im concerned."
    Last edited: Nov 15, 2010

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