I'm about to change out the water pump, thermostat, and idler pulley. This pulley is on the upper right of motor and has a fouth of the rear shoulder missing. I assume this is not correct. The pulley is also making some noise. I've never worked on MB before and was wondering if there are any things I should know before I start. I plan to replace the drive belt also. The sensors on the water pump I plan to reseal with liquid pipe dope. Any tips or info would be appreciated. I did the search and did not find anything on this car or procedure.