So I just bought a 00 ej25 SOHC motor with 30K miles. I have been reading around how the rod bearings fail. Any recalls on the bearings itself or using a diff wt of oil? I still have my 2.2 with 136k miles and it drives great. No leaks and starts up everytime. I bought the 2.5 to get more hp. e46 m3's had problems with the bearings and BMW recalled 01'and some 02's and replaced it with stronger bearings. Also a change of oil wt from 5w 30 to 10w 60. Any thoughts on how to prevent this would be great. I havent installed the motor yet.

 

2.5s dont have rod bearing issues, its piston slap, often mistaken for rod bearings

 

what is piston slap?

 

its when the bottom of the skirts of the pistons start to wear and slap back and forth in the cylinder, makes a knocking type noise, if not serious, goes away when the engine warms up

 

well here is something i know a little about, piston slap.
i had it, there is a noise a rappiung on metal sound that goes up and down with the rpms, it sounds great, likes wet shoes in the dryer.
anyways the fix it by taking your engine apart, totaly apart.
at first they thought it was the timming belt, the changed that, stilll it wast there.
then the split the engine got new pistons wrist pins, conecting rods crank shaft, and bearing. and put it back together.
the bearing were shot is why it started in the first place, the other thing is i personel felt the was something wrong with the engine from the start casue 20k is not going to wear out an engine.
i wanted a new short block assembly or engine but warranty won't do that. but insurance will.
but my favorite part about the whole thing CERTIFIED TECHNITIONS, my favorite people in the whole world. they glued the engine back together, but sealed up the oil return lines, so with no further ado the oil desides it need s to go somewhere like out the main bearing seal on the crank out into the clutch housing and start to came out all over everytinhg like the headers.
i take it back now, they take it apart agian, put it all back together, drive it for awhile and guess what happens again, boom right out the back again.
so guess what happpens next take it apart for the 3rd time, reassemble it, i get it back.
now here comes the best part a few monthes later ivan comes through, hydro locks the engine, insurance says drop a new engine in it. now it runs great better then when i got it, but the only drawback is my throw out bearing is shot, it makes a sliding grinding sound when the clutch is depressed. in gear it runs great. my favorite part about it is they put the new engine in drive it around say it is good and they give it back to me with this noise, i just do not get these people. ooh yeah when i got the new engine the said my amp was shorting the battery out, and did not know what i was doing, and they checked everything took my new battery replaced it with one of there peices of junk, remember they checked everything, so i checked the altenater it was bad. replaced it with one from the scrap yard 60$ they wanted like 320 for a new one, dropped it in, itworked great have not had a problem since, ooh also got a optima red top.
ooh plus when i changed the altenator i found an altenator braket laying on top of the engine so i have 2 of them now, so this lead me to belive they swapped the good one on the engine with a shot one.

moral is fix it yourself if you got the time. how much worse can you do of it, if all else failsyou can always take it to them.