timing belt or timing chain?

Discussion in 'General Motoring' started by yat70458, Jan 15, 2006.

  1. yat70458

    yat70458 Guest

    I was reading an earlier thread about when to change out the timing belt.

    Please excuse my ignorance...I am not a Hyundai owner yet but am seriously
    considering the Tucson or Sante Fe. I thought most new cars nowadays used
    timing chains, which I heard can last forever.

    Thanks for your response.

    yat70458, Jan 15, 2006
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  2. To this day, most of the domestics still use a timing chain, and rarely does
    one ever think about them. A few of the DOHC engines (like the 3.2L and
    3.5L in the Dodge Intrepids of the last dozen or so years) used a timing

    Imports much more frequently have used a belt. It allows (supposedly) for
    smoother, quieter operation and better fuel economy for the set-up. But of
    course, any belt is a maintenance item, and since many of those engines are
    "interference" engines, meaning if the belt breaks, you bend or break some
    things in the engine (valves, etc.), you best not forget about it.

    Something to ponder when you are deciding which vehicle to buy. (All Santa
    Fe engines for sure would have timing belts).

    Green Valley Giant
    Rev. Tom Wenndt, Jan 15, 2006
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  3. The Mazda 2.3 DOHC engine has a timing chain, which by itself is good.
    It also has something called "Variable Valve Timing", which sounds to
    me like a failure waiting to happen.


    Screwtape III, Jan 15, 2006
  4. I'd say most domestic V-6 and V-8 engines have timing chains, but most
    of the domestic I-4's, which by and large are based on foreign design,
    use timing belts.

    Screwtape III, Jan 15, 2006
  5. yat70458

    Mike Marlow Guest

    Not as much of an eminent failure as you might think. Variable Valve Timing
    (in different forms) exists in a lot of engines these days. Most
    manufacturers either have a form of VVT or are experimenting with it. Some
    of the stuff that's being toyed with is quite radical for your basic
    internal combustion engine. It's not inconceivable that the camshaft will
    become a thing of the past, giving way to the ever-present computer, which
    will monitor and adjust valve timing.
    Mike Marlow, Jan 15, 2006
  6. yat70458

    Matt Whiting Guest

    My 2006 Sonata with the 2.4L engine has a timing chain, if the web site
    is correct. I think the new 3.3L V-6 has a chain also, but I'm less
    sure on that one.

    Matt Whiting, Jan 15, 2006
  7. yat70458

    Matt Whiting Guest

    So do the new Hyundai engines. Time will tell...

    Matt Whiting, Jan 15, 2006
  8. yat70458

    nothermark Guest

    And I will add that I am very pleased with the results. My new
    Alantra scoots much better than my Accent ever did. The VVT seems to
    broaden the torque curve quite a bit.

    nothermark, Jan 15, 2006
  9. yat70458

    BillyGoat Guest

    My first introduction to a timing belt was when the one on my mid-80s Escort
    broke. It was painful!
    BillyGoat, Jan 15, 2006
  10. yat70458

    Don Guest

    Although Gilmer (that's its real name!) timing belts seem to be a
    rather new innovation, they've been used for many decades. That being
    said, however, timing chains were generally used by most manufacturers
    before the shift to Gilmer timing belts.

    Most OHV engine designs used timing chains (most USA manufacturers) or
    timing gears (many European manufacturers). Actually, timing gears are
    the best, but can be costly to design and manufacture.

    In most OHC designs, timing chains were historically used. For
    example, the classic Jaguar DOHC inline 3.8L and 4.2L six used timing
    chains, as well as most other European cars including the SAAB SOHC and
    DOHC inline four. FIAT used Gilmer belts in their 124 series in the
    '60s. Mercedes and Porsche used, and still use, timing chains.

    Timing chains are more durable than the Gilmer belt. The generally
    accepted design spec for replacement of the Gilmer belt is 50,000 to
    100,000 miles. Hyundai specifies replacement of the belt at 60,000. On
    the other hand, a timing chain - either simlex or duplex - can last
    much, much longer. The primary problem with a timing chain design over
    time and mileage is chain stretch. This natural wear is compensated by
    a timing chain tensioner, either oil pressure or mechanically operated.

    One of the primary reasons for the original shift from a timing chain
    to the Gilmer belt is one of economics. Although the timing chain is
    more durable than the Gilmer belt, it's generally much more expensive
    to replace on an OHC engine than a belt. Not only is the timing chain
    itself more expensive ($50 to $200), the replacement (labor) can be
    very costly. In some OHC designs which use a timing chain, the engine
    has to be pulled to effect the repair. Whereas the Gilmer timing belt
    is inexpensive ($20 to $50) to purchase, and the replacement cost is
    much less than a timing chain. NOTE: Although we Hyundai owners may
    complain about this fact, it's nevertheless much less than a timing
    chain replacement.

    Timing chain replacement in the classic American OHV engine design is
    also quite inexpensive, both in terms of parts cost and labor.
    Although OHC engine designs are much more efficient, the efficiency
    comes at a long-term maintenance cost increase over OHV designs.
    Don, Jan 15, 2006
  11. One of the reasons for the increased cost of using timing chains (beyond
    the cost of the parts themselves) is that a timing chain must run in an
    oil bath, which in the case of automotive engines, is generally the
    sump. That means that it must also have an oil-tight cover over it.

    Timing belts run dry and need nothing more than a cheap plastic cover to
    keep out dust, dirt and moisture.
    Brian Nystrom, Jan 15, 2006
  12. yat70458

    James Guest

    And then there is my Fort Taurus SHO. Timing belt placement is such
    that one the case is opened it is better to replace water pump, front
    seal, Crank sensor and a host of other stuff as the labor charge is
    monumental. Lucky it's a non-interference engine.
    James, Jan 16, 2006
  13. yat70458

    yat70458 Guest

    Thanks for all the responses. All the information has been helpful. I get
    the opinion that the difference in having a timing belt over a timing chain
    is that the belt is less expensive...for the part as well as the
    installation. Having the belt replaced at 60k miles should be considered
    routine long term maintenance.
    yat70458, Jan 16, 2006
  14. Don wrote: "And then there is my Fort Taurus SHO. Timing belt placement is
    such that one the case is opened it is better to replace water pump, front
    seal, Crank sensor and a host of other stuff as the labor charge is
    monumental. Lucky it's a non-interference engine."......

    Actually, that is true with many vehicles, particularly the water pump.
    That is often used as the tensioner for the belt, making it something
    replaceable when you replace the belt with virtually no additional labor.

    But those who said timing belts are cheap need to price out some of them.
    The Kia Sedona minivan's does not come cheaper than $110 (that I can find).
    That is just the part - with labor, I have one quote for $450, and I have a
    hunch it won't get much cheaper. That is not chump change to me.

    Green Valley Giant
    Rev. Tom Wenndt, Jan 16, 2006
  15. yat70458

    Don Guest

    Rev. Tom Wenndt wrote: "The Kia Sedona minivan's does not come cheaper
    than $110."

    The best price I've found on the Sedona timing belt is $94. Thus, it's
    more expensive than your usual timing belt parts cost. I imagine this
    is due to the V6 design, and most cost references to belts are those
    used in Inline 4 cylinders.

    Although $450 is a significant amount of money, it's still cheaper than
    some timing chain replacements which require the engine to be pulled
    from the vehicle. This is most often the case in some of the European
    Don, Jan 16, 2006
  16. yat70458

    hyundaitech Guest

    You're correct, Matt. Both the '06 Sonata engines are chain driven.
    hyundaitech, Jan 16, 2006
  17. yat70458

    hyundaitech Guest

    I've never done a Sedona belt, but it's the same engine as the XG, and the
    access in the Sedona looks even worse than the XG's.
    hyundaitech, Jan 16, 2006
  18. yat70458

    Guncho Guest

    I was quoted $225 Canadian at the Oakville Hyundai dealership?

    Guncho, Jan 16, 2006
  19. yat70458

    Mike Marlow Guest

    True, but timing chains seldom require replacement.
    Mike Marlow, Jan 16, 2006
  20. yat70458

    Matt Whiting Guest

    Except that most timing chains (well, speaking for American engines - I
    don't have experience with European designs) will last the life of the
    rest of the engine. By the time the timing chain is shot, it is time
    for a complete overhaul anway. My Chrysler minivan had 178,000 miles on
    it when totaled and the engine was still running fine with all of its
    original internal components.

    Matt Whiting, Jan 16, 2006
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