Engine Misfire and/or Lack of Power on Mercedes-Benz SL600

Problem Description and Possible Solution

Engine misfires (rough running) and lack of power are commonly caused by ignition coil pack or ignition module faults. Proper diagnoses should isolate the cause and prevent unnecessary replacement of good parts.

Problem Data
RepairPal Verified
Average mileage: 39,571 (32,000–47,000)
6 model years affected: 2004, 2005, 2006, 2007, more2008, 2009
14 people reported this problem
Viewing 1 - 6 of 6 comments
Check engine light came on, told I need to change coils $2600, now still happening brought it in to another mechanic for diagnosis, told still misfiring in 2 cylinders. Back in the shop now.
had this problem first in 2009 and had the dealer misdiagnose the source and changed all my spark plugs. ( expensive deal on this car)... But that wasn't the problem, apparently! Since then a number of times the check engine light would come up & I would validate with my OBD2 device that it was cylinder 11 misfiring. I took the car to the dealer again who saw BOTH cylinders 11 and 4 misfiring and requiring coil change at a cost of ~ $2k/coil !! If that recurs again I am dumping this lemon...
engine light on, misfire codes for 6 cylinders, turn engine on and off take care of the problem temperary and happen again, now happen all the time.