By on August 5, 2011

Mercedes-Benz is currently trying to recapture the number one position in global luxury sales, but  a quality problem on its home turf in Germany seems to be undermining confidence in the brand. Autobild reports that the M272 V6 and M273 V8 engines used a sintered steel timing chain gear made of various materials starting in 2004, but switched to conventional steel in 2006, eliminating the problem with gear wear. The problem: nobody seems to know how many vehicles built between 2004 and 2006 are affected. Mercedes claims, based on secret internal defect tracking, that one percent, or about 1,500 vehicles, are affected. If you have a vehicle with one of these engines built between 04 and 06 and your check engine light comes on, Mercedes encourages you to visit your M-B dealer rather than an independent shop, as Mercedes is offering free repairs to affected customers. And as Autobild’s Matthias Mötsch argues, when your motto is “the best or nothing,” the only answer to a situation like this is to fix 100% of the defects for free.

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29 Comments on “Mercedes Hit With Timing Chain Issues on 2004-2006 V6 and V8 Models...”


  • avatar
    PintoFan

    Such a contrast to BMW that it’s hard to believe they are both positioned in the same segment. Yet it appears once again that Daimler rises to the standard of what a true luxury maker ought to be, while BMW continues to give their customers the runaround on their (all too numerous) quality defects.

    • 0 avatar
      ellomdian

      A more accurate comparison would be between this and the IMS failure for Porsche. When it comes to catastrophic failure, BMW and Mercedes tend to even each other out for replacing things for recent customers. They are both still HORRENDOUSLY bad at supporting enthusiasts – people who drive their very special 15-30 year old cars.

  • avatar
    Educator(of teachers)Dan

    So does this affect Chrysler Crossfire (3.2ltr MB V6) owners?

  • avatar
    evan

    How in the world is a ‘about-ready-to-fail’ timing chain going to trigger a check engine light?

    In that circumstance, all I can imagine is that it somehow expands, stretches, etc. and the valve timing goofs enough to trigger rough running, emissions, or whatever issues that will trigger a light. But how many timing chains simply stretch when they fail? In my experience, they simply break, with maybe a few minutes or seconds of noise beforehand as the only warning (if you’re lucky). And then, of course, if you have an interference engine, as I’m sure these are, its a catastrophic failure. Hmmm…. What am I missing here?

    • 0 avatar
      TR4

      Educated guess: modern engines have electronic position sensors on both crank and cam shafts. I know for a fact that a Neon engine can sense a one-tooth error in the cam timing so I expect that if the limits were set tight enough the M-B could sense a worn chain/gear the same way.

      • 0 avatar
        bam210135

        TR4 is right. The issue on the engines is either a worn balance shaft gear(v6) or idler gear(v8). Both engines have electronic valve adjustment and when the gear wears out the right side cylinder bank cams become retarded past adjustment parmeters. Engine computer sets a code and turns the idiot light on. The chain tensioner takes up enough slack and the chains not going to break so pistons dont meet valves. Ive rebuilt 2 of the v6s at the MB dealership I work at.

  • avatar
    Morea

    Sintered metal timing chain gears? Can you say ‘crack initiator’? Is this common, can anyone chime in? Sounds to me like a recipe for trouble.

    • 0 avatar
      ellomdian

      I thought the same thing. Jesus, might as well use a belt…

      • 0 avatar
        Robert.Walter

        Since the early 1990′s, all Ford modular V6, V8 and V12 engines have camshaft assys with sintered gears… I know because I helped develop them…

        btw, IIRC, the largest automotive supplier of powder-metal parts in the world is GKN; I don’t know if they make the mb part…

      • 0 avatar
        2ronnies1cup

        Speaking as someone with some experience in industrial metallurgy, there’s nothing wrong per se with sintered components as long as they are properly made. The problem is that faults in the manufacturing process only tend to show up after a very prolonged period of mechanical and thermal stress cycles. This makes it basically impossible to get meaningful results from quality assessment tests on subcontractor-supplied components during production. That there were most likely more than one supplier of these components to MB doesn’t help matters.

      • 0 avatar
        Morea

        If you don’t get the heating and pressure cycles just right the parts will be sub par. So Mr. Walter, why does Ford risk it? Is it that cost effective?

        Remember, it was a heat treating failure of a subcontractor to Tremec that made the Camaro output shafts fail leading to a recall. (Not a sintered part, but nevertheless…)

      • 0 avatar
        Robert.Walter

        It’s effective. Light-weight, robust and cost-effective. The teeth are induction-hardened for strength and wear-resistance. Easy to machine and (not in every application) to press-onto the camshaft quill.

        Millions and millions of these things have been used with few problems. In fact, the problems are often due to other parts of the camshaft.

        Powdered metal is no less legitimate than any other manufacturing process, and no less robust if properly used (i.e. not for the wrong application), properly designed and properly manufactured. Obviously, this could also be said for any material or production process.

      • 0 avatar
        Morea

        Thanks for the info. Good to hear from someone who has experience.

      • 0 avatar
        Robert.Walter

        btw, I’m only speakng in the abstract about PM components found in the Ford cams (not including the Yamaha crap cams in the SHO) and to a leser extent the cams used in some Chrysler engines.

        Since I don’t know the MB camshaft, nor its sprocket, i can’t say much specific here, except that if the failure rate is so small, this sounds more like a mfg quality issue, rather than a design one (or a marginal design, not robust enough to withstand the normal variation within the mfg process chosen to make it.)

  • avatar
    rpol35

    Seems peculiar that only 1,500 engines would have been manufactured with this type of chain. Usually production volumes for a specifically engineered part are higher than just 1,500.

    Makes me wonder if they switched materials because they “suspected” a potential problem with the sintered chain and decided to wait and see what would happen.

  • avatar
    Zackman

    The Mercedes version of the Ultradrive issue?

  • avatar
    gslippy

    Engineered like no other car in the world. Somebody had to say it.

    • 0 avatar

      I just thought about it too. Why not make these part from plastic? They could save couple of bucks per engine and for 1500 engines it is like several grands – lot of money saved :) and as a bonus engineered like not other car in the world. On serious note – all these “like nothing else in the world” statements remind me “the standard of the world” – pure travesty. It might be correct in 19 century or in 30s but I cannot take all these claims seriously. Well engineered car cannot break all the time and made from crappy materials in places where customer cannot notice (think VW).

  • avatar
    ClutchCarGo

    Let’s see; 1,500 engines out of 150,000 might have the bad timing chain, but M-B wants all 150,00 engine owners to bring any CE light into the dealership, where the 1,500 owners with the bad chain will get a free replacement, while the other 148,500 owners will get the hard sell on fixing whatever triggered the CE light (not to mention anything else that the service dept can find “needs doing”)? Sounds like a pretty good deal for M-B dealers to me.

  • avatar
    bam210135

    As an MB tech I can tell you we dread getting in an 05-06 vehicle in with a CEL. Its usually for another reason but theres always the chance of it happening. The “balance shaft job” is easily 30hrs of work and a major PITA, but we do it without changing the customer.

    • 0 avatar
      Robert.Walter

      “…but we do it without changing the customer.”

      That’s mighty kind of you folks. Sometimes when I’ve been to my MB dealer to complain about the quality of my MB product I’ve had the impression that they don’t want me to buy any more of their cars.

    • 0 avatar
      Bryce

      You do the job without charging the customer.
      Damn staight you do you already bled the customer white when he bought the bloody thing

      • 0 avatar
        bam210135

        Bryce I agree with you 100%. You pay 60-100K+ for a car you should be taken care of when theres a defect. Would I pay 60 grand for a new one? No. I’d wait 2-3yrs and get a CPO’d one for 30. Also while we’re fixing their car, the owner gets a chance to sample one of our newer cars in the form of a loaner (just one of the ways for us to get you thinking about getting another one).

  • avatar
    John Horner

    A bit of nitpicking. If the chain touches it, the part is called a sprocket, not a gear :). Gears mesh with other gears. Sprockets make contact with chains, like on a bicycle.


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