Saturday, November 24, 2012

Rod Bearings on S54

Most know the rod bearings are a weak part of the BMW S54.  Recall "fix" or not, my opinion is the narrower bearings and higher rev range versus the S52s cause premature wear.  I've resolved to pretty much concluding that rod bearings on S54s are a routine maintenance item.

The following picture was taken from a 154k mile 2003 M3.  These look BAD.  Don't let the high miles fool you though.  Ive seen similar when I tore down my racecar's motor (90k).

Not trying to scare people, but if youre over 100k miles on a street car, it's probably a good idea to replace.


The one nice thing I noticed this time around, was BMW has replaced their older packaging method for rod bearings.  They used to be shrink wrapped on hard cardboard which was quite annoying.  Now they are individually bagged and boxed!

The job pretty much consists of getting an engine support (Harbor Freight has these cheap).  Then you have to drop the front subframe.  After the typical removal od the undertrays, etc, the process is fairly straightforward and requires unbolting of various tubes and lines to the exterior of the oil pan, then removal of the oil pan itself.  The power steering pump will have to be unbolted and moved out of the way as well.

You need 12pt 12mm sockets (rod caps), 18mm sockets and wrenches, 10mm sockets, 13mm sockets, hex sockets (removal of oil pump), e-torx sockets (bolts between transmission and oil pan) and of course a 32mm socket to rotate the engine.