Weird rattle sound like something stuck in the fan???

Discussion in 'Engine / Swaps etc.' started by 84hurst, Jul 1, 2010.

  1. 84hurst

    84hurst Apprentice

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    Allright im gonna try to describe this the best i can. i have a stock 84 H/O with the 307 of course, I get this weird noise kind of like a sound when something's stuck in a fan and kind of flaping back and fourth, Its always there when you start it cold, but then if you get on it when its warmed up it goes away. WTF??? It still does it in park so i can eliminate anything from the trans back. It gets louder as the engine rpm's rise, its not the smog pump as the barrings went bad so i cut the belt. The fan shroud is as clean as can be. So im lost as to what else could be spinning and making this noise? Anybody have any ideas or heard this???
     
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  2. othtim

    othtim Master Mechanic

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    I know this is an old thread. But all of a sudden, my car is making a sound that is very similar. I was actually searching through old posts looking for some help, but I stumbled across this thread which already accurately describes the issue I am having. Sounds like the fan is doing strange things, but it appears to be fine. Help? :S
     
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  3. 83hurst-olds

    83hurst-olds G-Body Guru

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  4. pontiacgp

    pontiacgp Rocket Powered Basset Hound

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  5. Bonegrater

    Bonegrater Not-quite-so-new-guy

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    My car started doing this, and it is the fan hitting the top of the shroud. I don't know why, but it stops after the engine runs for a few minutes. Could this be worn out body bushings allowing the shroud to be low enough to just tick the fan blades? Does anyone know why this would happen? I would like to get it fixed as soon as possible.
     
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  6. RockSS

    RockSS Master Mechanic

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    It could be the clutch fan wornout I had a similar prob on my elky ... when the car is OFF i repeat OFFjust grab a hold of fan and try to wiggle it if it moves time to replace and yes other things can fatige...
     
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  7. Peter

    Peter Royal Smart Person

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    waterpump bearing a possibility
     
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  8. G-Body_Vet

    G-Body_Vet Comic Book Super Hero

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    X2. Check for top to bottom and side to side play. Does it also sound like the rpm's are higher or like the engine is dragging? Those fan clutches do go bad. I've never seen one so worn that it would result in nicking the fan shroud though! It should spin freely too. If it doesn't you've managed to turn it into a factory flex fan.
     
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  9. bill

    bill Comic Book Super Hero

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    These clutches are fill w/fluid or are spring actuated. They should turn, but with resistance (depending on how cold the air temp, the easier it will spin). A free spinning fan clutch at normal operating temps usually indicates a lack of fluid in the housing or in other cases, the spring inside is broken or weak.
     
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  10. Bonegrater

    Bonegrater Not-quite-so-new-guy

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    Sorry it took a while to reply, the fan has no movement at all. None front to back and none side to side. I noticed it had stopped doing it for the last week or so. Then a friend from work rode with me to lunch, and he weighs around 290-300lbs. After he plopped in my seat I fired the car up and it started up again. After he got out it stopped, any ideas?
     
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