507 Horsepower Mercedes-Benz R63 AMG Minivan Yields Internet’s Best Rebuild Thread


Seth Lemke 2007 Mercedes-Benz R63 AMG R63 Smoking In Garage

Stop me if you’ve heard this one before: man buys extremely fast semi-exotic luxury car at a steep depreciation discount, and drives said vehicle for a brief period of time before it breaks in a horribly expensive way. Man then takes to the Internet to… document an extensive rebuild thread where he uses his own two hands to fix a problem the automaker wouldn’t touch?


I bet you were expecting something else at the end of that tale of woe, right? Like, say, a fierce online campaign waged against the builder of the vehicle in question, threats of a grassroots boycott, or at the very least 2,000 words of vitriol posted on an Internet message board in a fit of fiery rage? While that seems to be the standard operating procedure for anyone feeling wronged by the mechanical misery of their new driveway ornament, that didn’t even cross Seth Lemke’s mind when he was presented with a $57,000 repair bill for his 2007 Mercedes-Benz R63 AMG – or as he put it in his original thread found at Grassroots Motorsports, the ‘Unicorn of my Destruction.’


‘Mercedes-Benz canceled the program almost by the time you could buy one,’ Lemke told me in describing the R63. ‘They only made 180 of the AMG models, and you had to be one of those weird people who said, yeah, I want a $100,000 minivan.’

Seth Lemke 2007 Mercedes-Benz R63 AMG R63 and CTS-V Wagon 2

The Mercedes-Benz R63 AMG is indeed one of the stranger concepts to have emerged from Stuttgart, a hot rod version of the standard six-passenger people mover that swapped in a 6.2-liter V8 capable of 507 horsepower and 465 lb-ft of torque. Fed to all four wheels via a seven-speed automatic transmission, the R63’s phenomenal grip made it one of the quickest AMG models to date, capable of reaching 60-mph from a standing start in just 4.6 seconds.


Seth happens to have a thing for unicorns, having first cut his gearhead teeth on a series of self-described ‘crappy 80s hatchbacks,’ before adding an ultra-rare Cadillac CTS-V wagon to his collection, alongside the R63 AMG – both vehicles chosen due to their capability to swallow a car seat without complaining. Lemke took advantage of the depreciation demon that haunts most AMG products once they’ve been on the market a few years ago, and after a long three year search for one of the few well cared-for examples still available in the U.S., he ended up paying $35k for his. All was well for the first 8 months of ownership, when after 12,000 miles what some might call the inevitable finally happened.


‘I was on my way home from taking my kids to the dentist, when it broke. Suddenly, I was dealing with coolant in the oil, a check engine light, but no overheating, no smoke. I mean, you can’t buy one without knowing something horrible could happen, but I was trying hard to just stay calm until I could get a professional opinion.’

Seth Lemke 2007 Mercedes-Benz R63 AMG Coolant In Oil

The drama that would unfold over the next little while would play out on Lemke’s now well-quoted GRM posting, which he had originally made to track the maintenance and experiences he had with the van. Now it read like a play-by-play of his interactions with the local Mercedes-Benz dealership, which he said was surprisingly accommodating, especially given the fact that he had bought the car second-hand from a Dodge dealer.


‘They told me that my engine had suffered a failure where the engine head bolts actually have their heads break off and back out,’ he said. ‘It’s because they have an inverse torx design, where the hole goes into the bolt, and the theory is that the geometry creates a stress riser that snaps the head off. In mid-2010, they redesigned these bolts on all of the 6.2-liter M156 V8s to an outside torx, but every motor before that has this particular weakness.’

Seth Lemke 2007 Mercedes-Benz R63 AMG R63 Failed Head Bolt

As friendly as the dealer was, they were also bound by the book, which told them the only real repair was to replace the engine in its entirety. Seth’s cost? A mere $57,000, or 22 grand more than he had paid for the entire car. It was here that Lemke began to get creative.

Seth Lemke 2007 Mercedes-Benz R63 AMG R63 Failed Head Bolt 2

‘The dealership agreed with me that the entire thing was ridiculous – like I said, they were cool the entire time – but they didn’t really have any other options to present to me, other than the suggestion that I call Mercedes-Benz corporate and see if they would cut me some slack, Well, I was stuck in the corporate world for a couple of months while they made up their minds, and they eventually decided that they didn’t want anything to do with me.’


It was here that the dealer made a last-ditch effort to meet Lemke halfway, telling him that even though they didn’t want to warranty the work, they would be OK with pulling the heads off, investigating to see if there were any further issues, and if everything was fine they would replace the bolts and gaskets and put everything back together. They quoted him $11,000, of which $3,000 was labor – a price that seemed reasonable to Seth, especially given that an AMG master mechanic would be taking care of everything. Reasonable, that is, until he discovered the enormous mark-up on the parts they were selling him as part of that price.

Seth Lemke 2007 Mercedes-Benz R63 AMG Oil Filter With Coolant

‘I said cool, can you guys give me an itemized parts list to get a feel for what you’re replacing? They did, and when I cross-referenced all the part numbers I found out they were not only 40-50 percent above Mercedes-Benz list, but they were well over twice what I could find form another MB dealer. When I went in with my updated list, with a parts cost less than half of theirs, they said they’d maybe be able to work on their original parts price with me, but wouldn’t let me buy them anywhere else. That was the first time anybody did anything in the entire saga, to that point, that made me feel like I was being taken advantage of. And I thought, you know what – why not just take it home and fix it myself?’


Some quick back-of-the-envelope math showed Lemke that he could actually afford to buy a lift for his garage at home, plus all the parts, and still come out way ahead of the dealer repair quote – without even taking into account the incredible $57k replacement motor cost. Seth told me that to this point, he’d only ever put together one motor before in his entire life, an old Omni rally car that he’d bought ‘in about 10,000 pieces’ and had assembled from a short block armed with nothing more than the factory service manual and a set of hand tools.

Seth Lemke 2007 Mercedes-Benz R63 AMG Price Estimate for Engine Replacement from MB

This was the same approach he took to dealing with hand-built AMG V8. ‘Other than a special tool required to hold the cams in time so everything can be put back together properly, and another tool that a GRM member built to hold the crank so I could pull the crank pulley bolt out, I’ve been using the same set of Craftsman hand tools that I got 23 years ago when I was in high school,’ Seth confirmed.


As with almost every project, Lemke’s meticulously-documented R63 rebuild has grown in scope. ‘Right now the motor is disassembled down to just the rotating assembly, with everything off the block. The reason I did that, is once you have the heads off you have to do a go / no-go test from Mercedes-Benz to see if a rod has been bent, and by that point it was a case of, what else should I fix while I’m in here?’ Seth explained that hydraulic lifter scoring is another major issue for the M156, and after inspecting his it was clear they were ‘right at the edge of death.’ He also elected to swap in a new set of plastic timing guides.


‘I really don’t want to do this again,’ he said, ‘as there’s just so much labor in dropping the engine out of the bottom of the van and opening everything up for inspection. There are so many people watching this build now that I kind of feel obligated to do everything as factory-correct as possible, to preserve the AMG’s resale value down the road. I even cross-referenced with Loctite Europe and USA to make sure I used the Mercedes-Benz-specific RTV when putting everything back together. Oh, and I also changed the motor mounts, because why not, right?’

Seth Lemke 2007 Mercedes-Benz R63 AMG R63 Engine Out

Lemke is definitely not exaggerating how much of a spotlight has been shone on his GRM rebuild thread. He’s even noticed a drop in prices at auction on similar R63s when comparing values both before his well-publicized engine failure and afterwards. I asked him if he had considered simply swapping in a new motor, and he replied that a used engine would cost between $6,000 and $10,000 – and there’s no guarantee that it, too, wouldn’t suffer catastrophically from the same design flaw. The later corrected M156 motors start at $15,000.

Seth Lemke 2007 Mercedes-Benz R63 AMG M156 engine

‘Currently, I’ve got about $2,500 in parts in the project,’ he said, underscoring just how low his actual dollar investment has been, as compared to the labor involved. ‘That number’s going to jump to about $4,000, however, because I found a crack in a screw boss on the van’s hopelessly complex five-piece magnesium intake where someone over-tightened an injector rail. Just replacing that intake will cost me more than every other part I’ve already got in this car combined.


Cautionary tale or inspirational story? There are elements of both to be found in Seth’s dedication to resuscitating his 507-horsepower minivan, but one thing is for certain: the next time someone tells you that ‘modern cars are just too complex to work on yourself,’ you can quickly point them to Lemke’s thread, hand them a set of Craftsman tools, and drop the mic.

Seth Lemke 2007 Mercedes-Benz R63 AMG R 63 Engine Out 2

Something to Say?

One thought on “507 Horsepower Mercedes-Benz R63 AMG Minivan Yields Internet’s Best Rebuild Thread

  1. I’m reminded of the Maserati Quattroporte episode of _Wheeler Dealers_, where a buggy “fly-by-wire” throttle design was not only fixed, but improved, by A Man Running His Business From His Garage (in the literal sense).

    Let’s hear it for Men In Sheds!

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