valve noise or pinging noise?

Discussion in 'General Motoring' started by lamont1, Oct 18, 2004.

  1. lamont1

    lamont1 Guest

    hello, i just replaced a broken timing belt, the car started right up after
    the belt replacement but now i get a rattling sound from the engine when i
    accelerate under load, i never hear anything when im idling or when i rev
    the engine in neutral, i only hear it when im accelerating . im thinking
    after chaning the belt the timing is too far advanced plus, i did fil the
    tank with 89 octane before the belt broke. could somebody please tell me if
    valve problems create constant chattering sounds even in neutral or do valve
    problems become more pronounced during acceleration.

    it kind of makes sense that a new belt that isnt stretched like the old one
    would cause the timing to be advanced so im hoping its the timing and cheap
    gas and not the valves.
     
    lamont1, Oct 18, 2004
    #1
  2. lamont1

    Eric Guest

    It sounds like your engine is pinging under load. This can be very
    destructive for an engine so I recommend not driving your car until you
    solve your problem. The first step is to recheck the mechanical timing.
    It's easy to get the timing belt off by a tooth, so be sure to the
    mechanical timing is dead on. Next, have you checked the ignition timing
    with a timing light once you were finished replacing the timing belt? This
    is a standard double check that most techs perform. If everything was ok
    before you replaced the belt, then the ignition timing should not change as
    long as the mechanical timing is ok. However, if the old belt was off by a
    tooth and someone compensated for that by adjusting the ignition timing,
    then a correctly installed belt will cause pinging problems if you don't
    reset the ignition timing.

    Eric
     
    Eric, Oct 18, 2004
    #2
  3. lamont1

    motsco_ _ Guest

    =======================

    Breaking a belt will have about 90% chance of damaging SOMETHING. Did
    you ever test the valve clearances when you were putting it all back
    together?

    Have you done an (ignition) timing check with a timing light?

    You could just be out a tooth, so your cam is running several degrees
    too advanced, and causing ping, since cam drives distributor.

    Knowing what car and mileage would help too.

    'Curly'
     
    motsco_ _, Oct 19, 2004
    #3
  4. lamont1

    lamont1 Guest

    ok, i let the car sit for hours then i went and started it up and took it
    for a drive. turns out it didnt make a single sound the first ten minutes,
    when the car warmed up it started pinging . i say pinging because i know
    that pinging is caused by hot spots and it makes sense that it would get
    worse as the engine got warmer and you cant hear it at all when the engine
    is cold or warm.
    No i never used a timing light because i dont have one, i figured if i got
    the mechanical timing right nothing would change. I also figure the engine
    is running to0 strong and smooth to have a valve problem and i think valves
    sound worse when the engine is cold anyway. i will retard the timing
    tomorrow by ear until i get a timing light, i really dont have to drive much
    this week anyway.
    I guess im very very lucky to have no valve damage . i read that only 25
    percent of honda timing belt breaks end up with no damage. from now on im
    never going to let a timing belt go past 60k and i will check my belt every
    10k.

    i believe i didnt get bent valves due to the fact that my belt didnt
    actually break, instead a few teeth on the belt just came off. there was a
    six inche strip on the belt with no teeth. also, there was a lot of oil and
    grime in the bottom of the timing belt cover, i believe that the belt
    slipped enough to shut off the engine but not enough to cause the pistons to
    crash into valves. the belt that i took out was honda oem, that's probably
    why.
    i should have bought a honda oem but i dont think i will have this car when
    it hits 290k. it has 230k on it now and it looks great and runs great.
     
    lamont1, Oct 19, 2004
    #4
  5. lamont1

    Eric Guest

    It's unlikely you'll get the timing correct by ear. You could easily be off
    +/- 5° and not be able to tell if it's correct.

    You still need to double check the mechanical timing if you haven't done
    that already.
    Why? Simply removing the upper belt cover won't show you much except
    whether or not you have an oil leak. To really inspect a belt, it needs to
    be removed from the engine and bent backwards from it's normal orientation
    to open up the teeth. However, it's not recommended to do this on a good
    belt as it may weaken it. Just change the thing at the recommended interval
    and be done with it.
    This IS a broken belt. It's the principle mode of failure.
    That's more than a few. That's a near catastrophic failure.
    It sounds like you had a bad oil leak which caused the belt to fail. Oil
    contamination on the belt will soften the belt degrading the rubber and lead
    to its premature failure. I hope that you replaced the cam seal, front
    crank seal, and valve cover gasket while you were in there. Otherwise...
    Maybe, however it doesn't take much on an interference engine to bend
    valves. The engine can still run being one or perhaps even two teeth off on
    the mechanical timing. Any more and the valves will get bent. Six inches
    of shredded belt teeth is more than enough to lead to damage. You may want
    to do a compression check once you've got the mechanical and ignition timing
    straightened out.
    Then again, you may have just gotten extraordinarily lucky. Sometimes if
    the belt breaks at idle, then there may not be valve damage though this is
    rare. However, if the belt broke with the engine at speed there are nearly
    always bent valves.

    Eric
     
    Eric, Oct 19, 2004
    #5
  6. lamont1

    lamont1 Guest

    1) actually, i retarded the timing, i believe that a retarded timing cant do
    damage to the engine like advanced timing can, perhaps i will get low
    effiiciency on gas but i wont run the risk of damaging pistons and valves .

    2) i seriously doubt that i have bent valves. my theory like i said before ,
    is that some teeth came off and the engine stopped. when i pulled over i
    tried to crank the car then tried to crank it in the impound lot, that might
    ripped more teeth off.

    3) the belt didnt break due to an oil leak its due to the fact that the belt
    probably has 100k+ miles on it. i replaced it with a new dayco belt that i
    bought at strauss discount auto.

    3) i really dont think the mechanical timing is off because after i put the
    new timing belt on and tensioned it, i set the first piston to tdc and
    checked the marks on the pulley twice.

    4) i retarded the timing last night and every thing is running perfectly
    with no noises but i will still get a timing light and adjust it next week.

    5) im the luckiest man on earth hahahhaha
     
    lamont1, Oct 19, 2004
    #6
  7. lamont1

    Jafir Elkurd Guest

    86-89 accord usually DON'T bend valves when the belt breaks. If you had
    done this in an 88 prelude Si, you'd be the luckiest man on earth.
     
    Jafir Elkurd, Oct 19, 2004
    #7
  8. lamont1

    N.E.Ohio Bob Guest

    No, Dan Quale is. bob
     
    N.E.Ohio Bob, Oct 21, 2004
    #8
  9. lamont1

    lamont1 Guest

    I HEARD THAT ALL HONDAS ARE INTERFERENCE ENGINES. HOW DO YOU KNOW THAT THE
    87 ISNT?
     
    lamont1, Oct 23, 2004
    #9
  10. lamont1

    Caroline Guest

    Gates.com says most Honda models from the 1970s to 2001 have interference
    engines, but not all. (It doesn't have info on 2002 to the present engines.)

    NOT interference, according to Gates:
    Civic 2001
    Passport 1994-2001

    http://www.gates.com/brochure.cfm?brochure=981&location_id=540&go=preset663Gates
    (open the pdf file listed near the bottom)

    So I don't know if the statement below about the 1988 Prelude is correct. Gates
    mentions Si versions of the Civic but not the Prelude, so maybe Gates is
    incomplete.

    But nor can I tell if there are some interference engines whose valve design and
    timing are such that, even though it's interference, the damage is less likely.
     
    Caroline, Oct 23, 2004
    #10
  11. lamont1

    Eric Guest

    It would depend on where the cam stopped rotating. If it stopped in a
    position such that the valves were only half-way open then one might escape
    valve damage.

    Eric
     
    Eric, Oct 24, 2004
    #11
  12. lamont1

    Caroline Guest

    This is true of any interference engine, no?

    Damage is never guaranteed when a TB on an interference engine breaks; it
    depends on where the timing is when the belt breaks, engine RPM at the time of
    breakage, etc.

    I'm wondering whether there are certain designs of interference engines that, I
    dunno, have a different valve angle or some other design feature that reduce the
    likelihood of damage when the TB breaks.
     
    Caroline, Oct 24, 2004
    #12
  13. Gates can be wrong. It lists my 85 Volvo 765T (2.3L B230FT) as interference,
    when it definitely isn't (even if fitted with an aftermarket cam).

    Mike
     
    Michael Pardee, Oct 31, 2004
    #13
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