2008 CLK 550, 124k miles. Check engine light came on. Checked the codes and am getting P0025 and P0015. Both indicating exhaust bank, right camshaft retarded. Is this an oil issue, sensor issue, or something else? Mobile 1, from new, every 5000 miles.

Thanks for any help.

 

See here for a translation of those generic OBDII P-codes to MBZ-specific DTCs:

http://benzbits.com/DTC/DTC%20209.372.pdf

You will find that P0025 = 0064 and P0015 = 0060.

Now, look here at Scenario #2 (page 4):

http://benzbits.com/BalanceShaftTSB.pdf

You have bad camshaft adjuster solenoids (a.k.a. cam magnets). Replace all four of them. If you want to DIY, it's not terribly difficult and you can buy all four for about $100:

http://www.mboemparts.com/oe-mercedes-benz/2720510177

It would just be removing three bolts per sensor, except that one is behind the oil cooler, so you'll have to drain a gallon of coolant from the radiator and remove it for access. Maybe 2-3 hours in the garage.

 

Having removed these recently to replace the seal on each sensor, I recommend you get a new seal for the oil cooler as well. A new seal is soft and pliable - the old one is crusty weirdness. I would not trust it to seal twice.