Cambelt

Discussion in 'Motorhome Chat' started by ShiftZZ, Sep 22, 2011.

  1. ShiftZZ

    ShiftZZ Funster Life Member

    Joined:
    Feb 19, 2008
    Messages:
    19,821
    Likes Received:
    35,861
    Location:
    Leicestershire
    Dumb question time..

    If a garage changed a cambelt on a Motorhome and they get ot wrong, how quickly will the owner know.
     
  2. rangitira

    rangitira Funster

    Joined:
    Jun 30, 2010
    Messages:
    6,253
    Likes Received:
    12,383
    Location:
    Cornwall
    As quick as the first try happens on saturday!:thumb:
     
    • Like Like x 1
  3. JJ

    JJ Funster

    Joined:
    May 1, 2008
    Messages:
    14,517
    Likes Received:
    25,640
    Location:
    Quinta Majay, Pinheiro Bordalo, Portugal
    I suspect it depends on how wrong they get it... one tooth out on the big cog might not be as bad as one tooth out on a little cog imo.

    Much more than that and you would know straight away I guess...

    JJ :Cool:
     
    • Like Like x 1
  4. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,441
    Likes Received:
    16,867
    Location:
    YO11 2BD
    if they got it wrong they want to update their method of replacing belts.

    once fitted the engine should be turned over TWO full revolutions BY HAND to check for clearance of valves and pistons THEN recheck timing marks.

    get it wrong and it will let you know first turn of the key unless its just the injector pump a tooth or two out and it will be a bugger to start...if it starts.
     
    • Like Like x 1
  5. darklord

    darklord Read Only Funster

    Joined:
    Apr 28, 2011
    Messages:
    1,241
    Likes Received:
    1,243
    Location:
    essex
    One of the symptoms is excessive smoke, or more smoke than before especially when accelarating under load.
     
    • Like Like x 1
  6. chesterfield hooligan

    chesterfield hooligan Funster

    Joined:
    May 12, 2009
    Messages:
    1,003
    Likes Received:
    452
    Location:
    Stanton Hill
    :Smile: Turning over by hand would be no good if the engine has hydrolic tappet's :Smile:
     
    • Like Like x 1
  7. Terry

    Terry Funster

    Joined:
    Dec 27, 2007
    Messages:
    10,722
    Likes Received:
    6,224
    Location:
    South yorks
    AT THE FIRST TURN OF THE KEY or when they give you a bill for 2k telling you you needed a new engine :BigGrin:It is possible for them to get the pump timing out by a tooth or two but as already said that causes smoke,lumpy running or not start
    terry
     
  8. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,441
    Likes Received:
    16,867
    Location:
    YO11 2BD
    sorry Brian, not so.

    if the engine isnt running, a hydraulic tappet NOT on a cam lobe will retain its clearance....ie no pressure to force it closed.

    if the belt timing is out by a tooth or two and the engine is turned that tappet will open the valve to the same extent as it would when the engine is running and the inlet valve would open either earlier than it should, so hitting the piston crown or later causing the exhaust valve to be still open slightly at the top of the piston stroke, so hitting the piston crown.

    a tappet which was under a lobe, ie valve held open and tappet slightly compressed, may clear the piston on the next revolution even if the timing is out.

    point being, at least a couple of valves will open early enough to hit the pistons when turned by hand hence best practise to turn by hand AND recheck timing marks once all slack has been eliminated before starting the engine. :thumb:
     
  9. aba

    aba

    Joined:
    Oct 27, 2009
    Messages:
    2,793
    Likes Received:
    1,119
    Location:
    yorkshire
    you would know very quickly
    i changed the belt on my old v6 vectra and i had one of the idler wheels slightly out.
    as per fitting instructions lined all marks on the 4 cam wheels and crank wheel.
    rotated engine by hand 10 revolutions and check for second marks on the belt for lining up.
    the marks on the belt matched the marks on the wheels however the wheel marks didn't line up on the casing marks so a couple of hours later id got it sorted but if i had turned the key it would be a matter of seconds before it caused enough slip to destroy the valves.
    after 10 revolutions of the engine the first 2 cams had effectively rotated backwards an 8th of a tooth not a great deal really a couple of degrees but at 800 rpm idle it would have gone backwards very quickly.
     
  10. W18BLA

    W18BLA Funster

    Joined:
    Oct 24, 2009
    Messages:
    348
    Likes Received:
    34
    Location:
    West Midlands
    If it was a Fiat Panda 1.2 you wouldnt have to worry as it is a "Fire" engine which is a none interfering engine so it wouldnt matter :Wink:
     
  11. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,441
    Likes Received:
    16,867
    Location:
    YO11 2BD
    very true, and there was no mention of what type of engine in the original post...petrol or diesel :Doh:

    I doubt you'll find any diesels in the fire category though !
     
  12. movan

    movan Funster Life Member

    Joined:
    Dec 2, 2009
    Messages:
    12,792
    Likes Received:
    22,317
    Location:
    Moving around
    :Sad:Getting really panicky over all these technical things that can go wrong with my van.... wish I was a man:Sad:
     
    • Like Like x 1
  13. lesleyjean

    lesleyjean Funster

    Joined:
    Jun 21, 2008
    Messages:
    2,150
    Likes Received:
    1,941
    Location:
    Devon
    Hi joy

    Don't get panicky,

    just smile nicely and explain any situation and wait for the man to volunteer to do it for you.

    Keep encouraging them ie, tell them how clever they are etc and then job done.

    Lesley:Rofl1::Rofl1:
     
    • Like Like x 2
  14. movan

    movan Funster Life Member

    Joined:
    Dec 2, 2009
    Messages:
    12,792
    Likes Received:
    22,317
    Location:
    Moving around
    :Smile:Hi Lesley Jean, It's alright for you to say that ..... I'm not sitting naked in a glass of bubbly ..... they don't come flocking to ME.:BigGrin::Wink:
     
    • Like Like x 1
  15. BobProperty

    BobProperty Read Only Funster

    Joined:
    May 20, 2010
    Messages:
    272
    Likes Received:
    32
    Location:
    Stockport
    Have you ever tried that though? :getmecoat:
     
  16. movan

    movan Funster Life Member

    Joined:
    Dec 2, 2009
    Messages:
    12,792
    Likes Received:
    22,317
    Location:
    Moving around
    :Smile: No, Bob but just bought the biggest glass ever ... does my bum look big in this? :Sad:
     
Loading...
Similar Threads
  1. musson
    Replies:
    25
    Views:
    1,148

Share This Page