Quote:
Originally Posted by B6T
Thought I'd share the wonderful situation I've ended up in and let people weigh-in on what went wrong.
Car is a 2008 335 RWD 6-speed, Sport model with the aux oil cooler. Mods are FBO; KW V3s, M3 sways, Michelin PSS, downpipes, ARM relocation intakes, VRSF intercooler, 335d coolant res, VRSF charge pipe, Tial BOV. Stock coils, index 10 injectors, pretty much stock everything else. I'm running the Stage 2 FBO 93 v5.1 octane MHD tune. No CELs, no weird codes, no misfiring, etc. Wastegates rattle but that's no surprise. Car has 180k kms on it (111k miles), nothing crazy, but getting up there.
Anyway, took it out to an open lapping day on Friday. Get out there and gradually turn it up and up. Get about 3 laps in and started going WOT down the front straight, hitting about 185kmh, which is moving for the track I was on. Following the straight is a long-ish 100deg right hander that's taken at about 100kmh, followed by another straight to about 160kmh, then a bunch of series of lower speed rights and lefts (2nd gear).
About 6 laps in I get the 'reduced engine power' message on the nav screen. I figured I'd overboosted or one of the turbos let go... so I took it easy and finished the lap (maybe 1.5km) and pulled into the paddock.
What's that noise I hear? A squeak and rattle? Damn that turbo must be fucked I thought. I park the car and give it a little rev... nope... that's knock. Fuck.
There was no oil pressure low indication, the oil was topped up, and the oil temp was mid-low on the gauge during all this. So I can only imagine the bearings weren't in the best shape to begin with, and they didn't like the 400ft lbs+ I was throwing at them.
In any case, I'll post up some pics after I get a chance to pull the engine and tear it down. I'm hoping I can install another crank (assuming the journals are fucked) and new main and rod bearings. I'd rather not buy another engine, mine was otherwise mint and ran great.
Thoughts... shared experiences...
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Rod bearing failure is not common on N54, not saying it can't happen.
What you experienced is most likely oil starvation due to pulling high G's consistently. Not sure if there's a Dry Sump system available for N54
Suggest you don't run V5 as mentioned due desensitised knock tables, read the same.
Run 7.1 or higher.