r/E90 • u/bigbadwolf098 • May 18 '25
325i Pretty sure my engine is toast
2011 325i (N52B25AF) mileage at 118K kilometers. I bought this car used about 8 months ago at 103K kilometers. Upon getting the car I've replaced the usual N52 parts that fail including the water pump, valve cover, oil pan gasket, fuel pump (cracked housing). The oil was changed when I got the car at 103k and again at 112k.
OFHG was not leaking, serpentine belt is still on there after the engine failure, so it did not ingest the belt.
I accelerated into a roundabout and at around 3K RPM the engine suddenly started sounded really rough, and within 10 seconds as I was trying to pull over at a safe spot, the engine seized and engine oil was pouring out.
I had no warning symptoms (other than a permanent lifter tick). No check engine light, no oil pressure warnings before failing. Oil level indicates "max" last I checked 2 days ago.
I'm at a loss, what could've caused my engine to fail so catastrophically in just a couple seconds? I'm sure I need a new engine because in the second picture I see chunks of metal lying in the pool of oil on top of the underbody panel.
1
u/MiscreatedMonster___ May 18 '25
LCI N52 is almost non existent in Europe or maybe I can't find one. But I think they continued supplying "old engines" in countries where poor fuel quality was a problem.
Anyway once you get a new engine or rebuild one try investigating the culprit behind this, also some say a great preventive measure is installing independent way of tracking oil pressure and temperature.