Engine Drivetrain 1st Gen Cooper S Tensioner: Why so scored?

Discussion in 'Tuning and Performance' started by Nathan, Oct 31, 2012.

  1. Jason Montague

    Jason Montague New Member
    Lifetime Supporter

    Jan 5, 2010
    6,134
    1,588
    0
    Physician Assitant (retired)
    Sherman,Tx
    Ratings:
    +1,588 / 0 / -0
    :cornut: Yeah I see that Nathan. But it appears to me that the male piston was grinding(up and down) in the female cylinder. Doesn't the piston travel in and out of the cylinder also?:Thumbsup:

    Jason
     
  2. BThayer23

    BThayer23 Well-Known Member

    Jun 12, 2009
    1,315
    154
    63
    Civil Engineer
    Durham, NC
    Ratings:
    +155 / 0 / -0
    There's also scuff marks higher up on the cylinder, too. Was the crankshaft balanced when the engine was rebuilt? I'm thinking the tensioner could be not just the cause but a symptom of something else vibrating.

    [​IMG]
     
  3. Metalman

    Metalman Well-Known Member
    Lifetime Supporter

    Sep 29, 2009
    12,731
    7,688
    113
    Ex-Owner (Retired) of a custom metal fab company.
    Columbus, Ohio
    Ratings:
    +7,960 / 1 / -0
    If this is the third design made on the tensioner.... It's quite possible the piston is supposed to rotate so you don't get a concentrated wear spot like the 100,000 mile example..

    If it's not a deliberate design function, well then......

    It still bothers me that they are "crunchy" when new..... That shouldn't be the descriptor for a close tolerance part.....
     
  4. Crashton

    Crashton Club Coordinator

    Jun 4, 2009
    19,445
    10,057
    113
    Retired old fart
    Hooterville Ohio USA
    Ratings:
    +11,698 / 2 / -0
    :ihih: :postcount
     
  5. Nathan

    Nathan Founder

    Mar 30, 2009
    25,144
    10,052
    113
    Writer
    Short North
    Ratings:
    +10,069 / 0 / -0
    Might have fixed this today with the help of Jan, Chad and Anson of Best Motor Werks.

    The rattle was back and really bad. Doing some more investigating it was determined that the head was decked at the last rebuild, but only 0.002 was removed. Not enough to really make a difference. However, that's not the first time it was decked and the amount shaved off in total is not known. The brain trust was thinking the tensioner did not have enough reach in it to pick up the slack. Since it had been making the noise on startup for some time it was also determined that there may be wear on the plastic chain guides too.

    We thought it might be best to give the tensoner a bit more reach before going in and replacing all the guides, sprockets and chain. Figuring it could be an inexpensive fix if it worked.

    So...how to give the tensioner a bit more reach? A washer!

    [​IMG]

    So far, so good. No more chain rattle.

    I tell ya, it's great to work with people and shops that think outside of the box. Try to get a dealer service dept to add a washer like that.
     
  6. Steve

    Steve Administrator
    Staff Member Articles Moderator

    Apr 23, 2009
    12,154
    3,164
    113
    Maryland, USA
    Ratings:
    +3,166 / 0 / -0
    Sometimes the best solution is the simple one.
     
  7. Crashton

    Crashton Club Coordinator

    Jun 4, 2009
    19,445
    10,057
    113
    Retired old fart
    Hooterville Ohio USA
    Ratings:
    +11,698 / 2 / -0
    Wow the head was decked & maybe more than once! Wonder why I never mentioned that to you. Guess I'm getting forgetful. :crazy:

    Glad you got it working! :Thumbsup:
     
  8. Dave.0

    Dave.0 Helix & RMW Powered
    Lifetime Supporter

    May 4, 2009
    25,021
    13,497
    113
    Burbs of Philly, PA
    Ratings:
    +14,644 / 10 / -4
    I love simple low tech solutions. Glad everything is back running nice again Nate.
     

Share This Page