Camshaft, how hard to turn?

Discussion in 'General Motoring' started by Forrest, Nov 19, 2007.

  1. Forrest

    Forrest Guest

    I have a 1989 Honda Accord SEI. It leaks oil and I have been letting my son
    drive it. I have lectured him about checking it frequently but wonder if he
    let it get too low. The engine quit on him as he was getting off of the
    freeway. I towed him home and saw that I had no spark to the plugs. I took
    the dist cap off and cranked it and the rotor didn't move. I removed the
    valve cover and timing belt cover and cranked and could see the bottom
    timing belt sprocket turning but not the top. I got the belt off and tried
    to turn the top, camshaft sprocket by hand and it wouldn't move more than a
    quarter of an inch. I figured that the cam shaft bearings may have frozen. I
    loosened the bearing caps and I could then turn it. A guy at a wrecking yard
    told me that it shouldn't have to be able to be turned by hand, but with a
    wrench. How hard should it be to turn? I hate to spend $30 on a belt, put it
    all back together, just to have it eat the new belt up. Thanks in advance
    for any replies.
     
    Forrest, Nov 19, 2007
    #1
  2. Forrest

    motsco_ Guest

    ----------------------------

    Isn't the '89 an Interference Engine? If so, the sticky camshaft may be
    only one of several problems. I don't remember how far back you have to
    go to find a non-interference engine....

    'Curly'
     
    motsco_, Nov 20, 2007
    #2
  3. Forrest

    jim beam Guest

    timing belt has gone.
    see above.
    use a wrench. it's held by powerful springs.

    that's because you loosen the springs.

    now you've loosened the caps, you've broken the plug tube seals and need
    to get new ones. you can remove completely to check the bearings, but
    unless the motor's been run dry, or run with the belt excessively tight,
    they'll be fine. tip: remove the whole assembly, with bolts in place,
    as one unit and keep it all together. reassembly once it falls apart
    can be a pita.

    other than that, you need to see if any valves are bent from the belt
    breakage. re-tighten the bearings and check for valve lash. if any are
    excessive, valves are bent and the head needs to come off for
    replacement. based on what you've said so far, i suggest you then hand
    the vehicle to someone with the experience to take the job from there.
     
    jim beam, Nov 20, 2007
    #3
  4. Forrest

    Forrest Guest

    you can remove completely to check the bearings, but
    Jim Beam wrote:

    "now you've loosened the caps, you've broken the plug tube seals and need
    to get new ones."

    I don't know what those are. Could you please elaborate on that point? Sure
    I can't just align it all, re-torque the caps and put on the new belt?
     
    Forrest, Nov 20, 2007
    #4
  5. Forrest

    Tegger Guest



    jim is referring to Honda's sytem of SOHC head design. There are O-rings
    that keep oil out of the spark plug holes. You may not be able to get those
    to seal again without replacing them. Big job!
    http://www.tegger.com/hondafaq/oilyplugs/index.html

    1) Depending on how careful you were when loosening the bearing caps, you
    may or may not have distorted the camshaft. This would require camshaft
    replacement.

    2) The valves may be bent, preventing free rotation of the engine. That's a
    head-off job to fix, and very expensive.

    At this point I'd say the quickest way to find out what you've got is to
    retighten the bearing caps, pull the pistons all down to half-way, then
    turn the camshaft so you can check all the valve clearances. If you have
    one or more that are wildly large, that valve's bent.
     
    Tegger, Nov 20, 2007
    #5
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