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 5.4L 'bulletproof' reputation on the CLK55
Mercedes-Benz CLK55/CLK63 AMG (C209) · mechanical