NHTSA Service Bulletin 11020807: 2015-2025 Mercedes Benz Amg C63

Complaint Customer complains of oil use, oil leaking or oil smell. Upon inspection oil will be seen at or around the rear of the engine and at the engine/transmission interface. Cause Oil leaking from rear main seal and/or rear main seal plate. Remedy If the rear main seal plate has been previously replaced per the instructions in this LI, open a TIPS case before proceeding. Inspect the rear main seal very carefully. Make sure the seal is not sucked in, rolled, or cut (see pictures in attachments). Confirm the leak location is at the rear main seal and/or rear main seal plate by cleaning the area thoroughly and applying trace powder to the suspected area. Allow the vehicle to run either on a lift or at low speed in a controlled environment (do not attempt at high speed or in wet areas as this will make the results difficult to assess). If the leak is emanating from the seal: replace both air/oil separators. Then clean the bellhousing area completely and test with trace powder again to see if the leak remains. If it doesn't, release the car. If the leak remains pull the rear main seal plate, clean the block mating surface completely and replace the rear main seal plate and rear main seal. When the new seal is installed make sure the sealant path is followed exactly as it is shown per the drawing in the attachments. Apply the sealant to the BLOCK instead of the plate to ensure adequate coverage is attained. After installation lubricate a feeler gauge with oil and run it between the rear main seal and the crank to clear any small debris that may be present and to break any binding or stiction.