Mercedes-Benz CLK55/CLK63 AMG (C209)

60 sales analyzed · 18 topics from real Bring a Trailer & Cars & Bids comments.

“I drove one of these a few years back and I felt like Captain Picard going to warp nine when I stepped on it.”Dm123 · Feb 15, 2019 at 4:30 PM

• M156 head bolt anxiety on the CLK63mechanical
  Nearly every CLK63 listing draws head-bolt questions, and the community consensus is that failure is rare, that Mercedes and specialists do not recommend preemptive replacement absent symptoms (coolant loss, oil contamination), and that the job is only worth doing if the valve covers are already off. Proactive replacement quotes cluster around $3,700 for bolts plus cam-adjuster plates. …
• M113 5.4L 'bulletproof' reputation on the CLK55mechanical
  Owners consistently describe the naturally aspirated M113 V8 as one of the most reliable engines AMG ever built, praising it as the last of the hand-built motors with no signature 'timebomb' defect, in explicit contrast to the M156's head bolts and other marques' known failures. …
• M113 oil leaks: valve covers, rear main seal, oil filter housingmechanical
  The near-universal maintenance item on CLK55s is oil seepage. Valve cover gaskets are the most common leak point and are frequently done preventively (roughly $800-$1,000), while a slow rear main seal weep is described as extremely common and not urgent, and oil filter housing gaskets also leak with age. …
• Convertible top hydraulics and seam separationmechanical
  Cabriolet owners repeatedly flag the powered top as the big aging expense: multiple hydraulic cylinders with seals that dry-rot and leak, plus the fabric separating at the seam above the rear window. Costs cited run into the thousands, though some faults are trivial (electric relays) and the top's tensioning straps can be a cheap DIY fix. …
• CLK63 production rarity and collectibilityhistory
  The CLK63 was built only for 2007-2008 and sold in the US only as a cabriolet, with commonly cited figures of roughly 143 for 2007 and 100 for 2008 (about 243 US cars), and just under 1,200 worldwide. Sellers lean on these numbers to argue future appreciation as hand-built naturally aspirated AMGs disappear, though exact counts vary between commenters. …
• Market: sleeper value and softening CLK63 pricesmarket
  Buyers routinely call results 'stolen' or 'well bought' and frame the cars as enormous performance-per-dollar, especially versus modern four-seat convertibles. At the same time commenters observe that CLK63 cabriolet prices have drifted downward and never gained the traction of other M156 AMGs, attributed partly to maintenance cost. …
• Sleeper and stealth driving characterdriving
  Owners love the car's understated look hiding serious power, describing it as a 'stealth' or 'German muscle car' that surprises with its acceleration. The theme recurs across coupes and cabrios, both stock 362hp CLK55s and the more explosive CLK63. …
• CLK55 is naturally aspirated, not supercharged like the SL55history
  A recurring point of correction: the CLK55 shares the '55' badge and M113 block with the SL55/E55 but is naturally aspirated (362hp), whereas the supercharged SL55 made close to 500hp. Tells include the CLK55's 160mph speedometer versus the 200mph unit on the supercharged AMGs, and sellers sometimes wrongly call the engine an 'M113k.' …
• Pillarless coupe and the four-seat convertible advantagehistory
  Commenters prize the C209's pillarless body and, in cabrio form, its usable rear seats, repeatedly noting it as the only 400-plus-hp AMG convertible with four seats (same-era SLs being two-seaters) and that child seats fit in back. Note the cabrio's rear seats do not fold due to the rollover 'tombstones.' …
• CLK55 performance figures and rear tire weardriving
  The CLK55 is cited at 362hp and 376 lb-ft, roughly 3,600 lb, with 0-60 quoted between 4.8 and 5.2 seconds. The easy power makes it break traction readily, and owners note rear tires wear noticeably faster than fronts. …
• Ownership and maintenance cost expectationsownership
  Real-world running costs are polarized. One detailed CLK500-based owner budgets about $1,200 a year and treats the cars as cheaper to keep than replace, and DIY-inclined owners repair leaks for a fraction of shop pricing, while dealer-loyal owners describe vastly higher annual spend. …
• M156 intake manifold cracking and leaksmechanical
  Beyond head bolts, the CLK63's intake manifold is a documented failure point: poorly cast units crack and leak air, triggering check-engine lights, with replacement quoted around $2,700 for the part alone and roughly $3,000-$5,000 installed. Experienced owners list it alongside lifters, rear main seal and valve cover seals as the things to actually worry about. …
• CLK63 tuning: Renntech, VRP and Weistec to 500-540hpmechanical
  The M156 responds well to simple reversible tunes, with owners reporting 500 to 540hp from Renntech, VRP or Weistec stage-1 flashes, often on an OBD dongle that can be removed for sale. Tunes from a former AMG engineer's firm are viewed as low-risk, though a related C63 dyno confirmed roughly 450whp on a tune. …
• Supercharged CLK55 builds and the M113 vs M113k questionmechanical
  A subset of CLK55s wear kompressor/Kleemann/custom supercharger builds with cams, ported heads and tunes making 440-500+ rwhp. Knowledgeable commenters caution that the NA M113 uses high-compression non-forged pistons unlike the factory 9:1 forged M113k, so boosting the base engine 'is asking a lot' without careful tuning. …
• Slow automatic, no factory limited-slip, and paddle upgradesdriving
  The main dynamic complaints are a relatively slow automatic and the lack of a factory limited-slip differential, which makes traction easy to break. Owners note the steering-wheel shift buttons feel cheap and are rarely used, and aftermarket G-paddles are cited as a cheap upgrade that improves the driving experience. …
• 722.6 conductor plate as a known service itemmechanical
  The 5-speed automatic's conductor plate is raised as a known wear item around 100k miles, with a dealer cost cited near $1,500. Sellers push back that Mercedes does not formally classify it as maintenance, and one offered to fit a genuine plate before delivery for roughly $600. …
• Seat bladders, heaters and multi-contour seat faultsownership
  Front seat electronics are a common weak spot: the pneumatic multi-contour seat bladders (and their vacuum lines/pumps) fail, seat heaters go inoperative, and power-seat motors become finicky. Buyers specifically ask about seat heaters and bladders because they are known trouble areas on the C55/CLK55 generation. …
• Buying advice: what to inspectbuying
  Recurring inspection guidance centers on servicing oil/diff/transmission, checking belts and pulleys, confirming valve cover gaskets and motor/transmission mounts, and listening for front-suspension noise. The heavy V8 is noted to wear front suspension components faster than expected, and squeaks can be hard to chase down. …