Engine Specs - S65/S85 Rod Bearing Break In
These break-in instructions apply to all BMW S65 and S85 engines after rod bearing replacement.
Recommended Break In Oil
Break in oil is not needed after installing rod bearings.
Recommended Running Oil
Use your normal oil. Your normal oil may depend on your own preference. Many people believe 10W60 oil is too thick for factory rod bearing cleaerance. This is why we say to use whatever oil you normally use.
Recommended Break-In Procedure
- Rod bearings don't require any special break-in procedure. The normal break-in procedure of running an engine soft at low RPMs is intended to help the piston rings seal and to wear in other metallic parts that come in contact with each other. Rod bearings don't make contact with the crankshaft because an oil film separates the rod journal from the bearing itself. This is why replacing rod bearings doesn't require any special break-in procedure.
- Oil change during break-in is optional. While it's not strictly required to change the oil shortly after changing rod bearings, it's not a bad idea either. When installing new rod bearings, it's expected that assembly lubricants will be used. After a few miles, these lubricants will all dissolve and will be mixed in with the running oil. If you do change the oil after rod bearing installation, we recommend to change it after about 400 miles.