Calculated Risk: 1977 Mercedes 450SEL 6.9

Mercedes-Benz’s 450SEL equipped with the 6.9L M100 V8 is one of the automotive industry’s most well-known engines from outside of the U.S., thanks to boatloads of torque and being immortalized on screen in the car chase classic Ronin. That said, they are frustratingly expensive to restore and can make your mortgage payment seem like pocket change in comparison. This example here on eBay is said to “start and run well” but is still sold as a restoration project. Bidding is over $5K with no reserve. 

The seller seems to be in possession of numerous vehicles, but that doesn’t help prospective owners with understanding the true needs of this car. The body has been repainted, and it doesn’t resemble a stock color. Additionally, the 450SEL badge has gone missing, which does nothing to inspire confidence about the care it’s received to this point. Still, the body seems straight and rust-free and chrome trim around the windows looks good. The rear headrests aren’t split due to sun damage, which is common on neglected examples.

The interior presents nicely, with well-preserved woodgrain dash inlays and a seemingly uncracked dash. Seat tears are also said to be minimal. Here’s where the costs get out of control, however: the motor and suspension. The latter is expensive but fairly black-and-white, as most all air suspensions fail over time. The engine, however, is a wild card. Many project-grade examples have suffered from overheating at some point, and head rebuilds range anywhere from $500 to $800 per head – and those dollar figures are a few years old at this point.

If the car were repainted a factory color and more details were provided on its mechanical history, this 6.9 might look safe enough to take a gamble on. You can find better cars for nominally more money when compared to the potential rebuild costs, so the seller would do well to highlight more of the unknowns with this example to determine whether it’s worth taking on (and to what price point it is worth that risk). These are still monstrous performers by today’s standards and run like a freight train when running well, so the temptation factor is high.

Fast Finds


  1. Alan

    2 years ago I bought 1979 6.9 U.S. specs All original 59K miles black with bambo leather interior. Asking price was 40K I paid 37 . Almost showroom original with All books manuals & collectable Mercedes from 70s.
    To be honest I had 2 issues with car the hydraulic suspension failed I had it repaired and rear differential also & usual service items oil changes and AC recharge etc. Approx 7000 6.9s were built worldwide. This is the Real 70s Muscle big sedan from Mercedes

  2. Ex Benzo Tech.

    I built my customer a short wheel version 6.9

    Here it is :
    Took about a couple of weeks of work.

  3. Salt Man

    Money pit of the highest order.

    • The Walrus

      Exactly. There is nothing more expensive than a cheap German car.

      • Alan

        V true regarding most cars and especially the Mercedes 6.9 having complicated hydraulic suspension system which is Not repairable easily and in any Auto Garage. I believe My 79 6.9 is one of most original low mile example and clean still existing (25 years in storage by previous owner) and even then I had issues with suspension and rear differential.
        I was told by Master Mercedes mechanic it was mostly due to long periods of storage.

  4. JimmyJ

    Does anybody know why sellers cover their plates?
    To they cover them when they’re driving and parked in public places too?

    • RichS

      Relatively recent phenomenon that popped up on my local CL. Seems to me to be a futile attempt at preventing identity theft. I think most people are doing it because they’ve seen it done but have no real idea why they are doing it…

  5. JimmyJ

    I think your right Rich,if everybody’s doing it,it must be cool👍

  6. Rabbit

    Back in my youth, I worked for a sleazy wholesaler, running cars back & forth to auction. He had a couple of these, 79’s I believe. Man, what a sweet ride. Of course, this was 1984-86 & they were still fairly new.

  7. cliffyc

    Don’t know about the situation in the US,but die to FOI rulings car data os in the public domain now. So Ican tap in plate no. and get car spec instantly showing taxation details,insurance data,finance clear or not ,written-off data and more. I found out yesterday by chance that a neighbours car is showing up as untaxed for the last 7 (seven!),years
    Might leave an anonymous note on his screen to tell him to check it out.

  8. cliffyc

    Don’t know about the situation in the US,but due to FOI rulings,car data is in the public domain now. So I can tap in plate no. and get car spec instantly showing taxation details,insurance data,finance clear or not ,written-off data and more. I found out yesterday by chance that a neighbours car is showing up as untaxed for the last 7 (seven!),years
    Might leave an anonymous note on his screen to tell him to check it out.

  9. Peter R

    There is one near me asking $22K Can with a claimed $15k in recent repairs. They are reputed to be wonderful cars but very expensive to keep runnig right. I’d like a ride but doubt I’ll ever be an owner.

  10. Luke Fitzgerald

    Without knowing this cars history, but you could order these things with deleted badges – more common than not – are they faster than earlier 6.3s? now they were quick

    • Alan

      In theory and on paper also according to motor trend test the previous 280SEL 6.3 is 0.3 sec faster to 60 mph than the 6.9 engine has about 15 more hp and being a lighter car also makes sense. Here is link to the motor trend article

    • rururu

      US versions did not have the 450SEL badge, just euros. Also article says air suspension, it is hydraulic.

  11. Steve Visek

    Given how lazy the seller is with his plate cover up regimen, I must wonder if he has been equally lazy with maintenance.

  12. jim

    The colour does look factory – DB 931 magnetite blue (magnetitblau). The body tag on the radiator support panel will tell more.

    The the 450 SE L badge was omitted on the US market 6.9.

    All badges could be deleted by selecting option code 261

    If the car has been looked after, and it’s an easy thing to have checked, has no rust or poor accident repair work there’s no reason to be frightened. Yes parts are expensive, but you will rarely need them. The new owner should have the timing chain, guides and tensioner replaced as a precaution if there’s no record of the work.

    Oh, and get the wave circlips in the automatic replaced before they fatigue and break, that can be messy.

  13. Steve Visek

    I’m sure glad the seller didn’t take off those seat covers for the photos. I can’t imagine a potential buyer wanting to see the condition of the seats.

  14. Coventrycat

    Fingers over the number plates drives me nuts.

  15. Greg Member

    A rich friend from high school drove one in 1984. Course his Dad owned it and took care of repairs. But getting to the point….riding in that car at 100+ mph felt like you were lounging in an impressive living room! So comfortable, so quiet inside. We cruised from Sacramento to Monterey for the classic car show weekend, and that car was amazing! Of course it was just a couple years old. Whether or not that’s a stock color, I don’t like it.

  16. Dave Wright

    Looked at an identical car at the factory classic car sales area in Stuttgart last year, it was silver and Black, had been driven but a nice car. They were asking 109,000 euros. This is another car that has become very stylish in Germany and the prices will be rising particularly as the euro strengthens against the dollar. In the US, no one claimed that they were faster than a 6.3 but I am sure the European model is an animal unto its own. The delete markings option is very common in Europe. They want to keep the neighbors guessing about what they were really driving.

    • F

      In France, wealthy buyers choose the delete markings options to avoid getting attention from the tax man.
      Anyone can be audited and have his/her taxes re-assed based on apparent signs of wealth (“signes exterieurs de richesse”)
      No marking? no way to figure out if it is a 280 or a 6.9

  17. fran

    When I see people sticking up fingers over plates, I move on to another car, that just plain stupid.

  18. Leon

    I’m a plate collector. I laugh when I see this Plate is visible to everyone on the street then they cover it when they share a picture. Lol

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