S54 baffle upgrade

[Michael.p]

Hi everyone,




I have an E46 M3 sedan with the S54 engine. I replaced the rod bearings with ACL bearings about 3 months ago, and after around 1,700 km of break-in, the bearings failed again.




After starting to research the issue, I came across upgrades like an S54 oil pan baffle and related oiling improvements.




At this point, I’m starting to lose confidence in the engine. The car is my daily driver, so I’m trying to understand if these upgrades are actually important for reliability, and what can realistically be done to improve the engine’s durability.




Also, I’d like to know what the correct break-in procedure should be after rod bearing replacement, and how many kilometers are recommended.




Any advice would be appreciated.

[Obioban]

Did you check the crank and rods? Why did you replace them the first time (did you spin one)?

What you're experiencing is not normal, and therefore wont' be fixed by mods. The S54 has a pretty great oiling system stock. An engine with good crank/rods (hasn't spun/damaged them) is good for a LONG time with factory bearings/bolts. For a DD/street use, factory bearings with factory bolts, on a health engine with correct install, are good for 100,000+ miles. 200,000 if you don't routinely hit redline (as in, Z3M with 7500rpm redline s54 doesn't really wear out rod bearings ever).

Break in also isn't going to solve your problem. Either your crank/rods are damage, the bearings you installed were faulty/wrong spec, or the install was bad.