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Metal grating/rattling noise when accelerating only. What is it ? Video included

Discussion in 'Car Repairs / Maintenance' started by Rightboy91, 14 Aug 2020.

  1. Rightboy91

    Rightboy91

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    Hi
    The car is a Vauxhall Vectra 1.9 CDTI 120 bhp.

    When I accelerate the car I hear a grating / rattling type sound that seems to be coming from driver side front area. I can duplicate the sound with the car stationery by revving it. This issue seems to happen from 2500 rpm upwards.

    Does anyone have any idea what this might be ? It sounds a lot quieter on video because in person it is quite loud and definitely more noticeable.

    As it is sounds fainter on video I will tell you when I can hear it in the video. It is audible at

    0.03.
    0.07.
    0.12.
    0.15.
    0.21


    Thanks
     
    Last edited: 14 Aug 2020
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  3. Burnerman

    Burnerman

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    Alternator or belt tensioner bearing, I think.
    John :)
     
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  4. Rightboy91

    Rightboy91

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    Hi Burnerman

    I replaced the belt tensioner a few months ago brand new part
    When you mentioned alternator did you mean the pulley on the alternator ?

    Could it be that the drive belt tensioner has not been fastened tight enough to the car ? It feels tight enough by hand but I only used an Allen key type tool but I did get it very tight in my opinion I don't think it will be loose . I don't know where I out the right size tool so I can't check it or try tightening it anymore atm.

    Thanks
     
  5. Burnerman

    Burnerman

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    The alternator has two bearings, one at the pulley end and one at the other.
    My guess is, if you slip the drive belt off and spin the alternator pulley by hand it will feel rough and sound harsh.
    The drive belt tension is not an issue here.
    With the belt off, start the engine and I think the noise will have gone.
    John :)
     
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  6. Rightboy91

    Rightboy91

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    Hi John.

    I had a mechanic replace the alternator about 18 months ago. I assumed it was a used replacement he fitted but I noticed the pulley on the alternator looked brand new ( as can see on the video it looks shiny and new but I am sure it looked old before alternator was allegedly replaced ) , so I assume he only replaced the pulley on the alternator and not fitted a used replacement I never actually asked him though her implied it as a used replacement complete alternator he fitted.

    I filmed a video of me spinning the alternator pulley when I replaced the drive belt and I was trying to figure out what was shredding the belt. I noticed the alternator pulley didn't spin freely it sounded a bit graty but a few weeks later when I took the drive belt off again I tried it and it did spin freely.

    When the drive belt shredded because of the bad tesnioner pulley I noticed some of the old belt was jammed behind the alternator pulley it was like string but I think I got it all out as it was like string I kept pulling it and it came loose it didn't snap so I don't think there will be any more old belt in there.

    here is a video of alternator pulley, in this video it spins freely , sounds a bit graty when I spin it backwards ( normal ? ) and sometimes it sounds graty when I spin it forwards though it doesn't in this video.
    there is minimum movement up/.down and side - side on the alternator pulley, is this acceptable ?



    is it ok to start engine without a drive belt attached ? it doesn't drive water pump on this car.

    thanks again


     
    Last edited: 14 Aug 2020
  7. Burnerman

    Burnerman

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    Alternators, and their freewheeling pulleys are separate items and not generally supplied as a complete unit.....if your alternator fails, for example, you won't necessarily get a new pulley unless you asked for one.
    So, although your alternator is recent, the pulley may well be the original.
    For an initial test, remove the alternator drive belt and rev the engine as you have done in the video. If the noise has gone we're on the right track - if it hasn't its thinking caps back on! You won't do any harm by doing this, but of course the battery charge lamp will remain lit.
    John :)
     
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  8. freddiemercurystwin

    freddiemercurystwin

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    Wow, this is the car that just keeps on giving.
     
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  9. HERTS P&D

    HERTS P&D

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    And heeeeeeeeeeeeeeeeeee's back, with another problem

    Have you thought about taking this car to a mechanic??

    Andy
     
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  11. HERTS P&D

    HERTS P&D

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    Question: Do you live in Liverpool?

    Andy
     
  12. Rightboy91

    Rightboy91

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    No, the car has another problem and I think you do too.
    So why bother to keep coming back ?
     
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  13. Rightboy91

    Rightboy91

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    I am not going to tell you where I live
     
  14. Rightboy91

    Rightboy91

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    It's not as bad as it may seem
     
  15. Rightboy91

    Rightboy91

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    Hi Burnerman, I see what you are saying so maybe he did replace the complete unit.

    Very good idea what you suggested I'll take the belt off and do what you suggested tomorrow and upload the results.

    So you are thinking it's a drive belt tensioner or alternator pulley and if one of the 2 how would I know which of the 2 it is ?

    I forgot to say as well the car also chirps when I start it up and has begun squealing usually in reverse and gears 1 and 2. This had been happening for about 2 or 3 weeks
     
  16. Burnerman

    Burnerman

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    When you start the car up, there is a large electrical load on the battery.
    Therefore, the alternator has to work hard to provide enough electricity to charge the battery up again....its under full load for a few minutes and takes a lot of energy to turn it.
    At this point, if the alternator drive belt is slack it will squeal for a while as it slips over the pulleys - a faulty alternator pulley does the same, unfortunately which is a real bore! The squeal is more prevalent in the low gears as the engine is revving hard.
    If your tensioner is new, then the suspicion must lie with the alternator pulley. Do the test with the drive belt off, then come back!
    The good news is, nothing is going to immediately fail so nothing to panic about!
    John :)
     
  17. delmel

    delmel

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    its a Vauxhall, had them for years as they are generally cheaper and easy for spares. Problem is they are also frequently needing work, after having other cars I would be reluctand to have a vauxhall again.
     
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