얼터네이터 교환PistonHeads★ 신뢰도 4.1 (높음)

BMW X5 수리 사례

2008년식 · E70 (2006-2013) · xDrive30d

2026. 10. 28. 작업

난이도 & 준비물

증상

Also had exactly this with my E46 after replacing the alternator with a refurbished Bosch unit, changed for a second refurbished alternator and seems to have stopped the random parasitic draw. Assuming again it was voltage leaking passed one of the diodes.

처리 내용

Jakg said: Having cleaned, reseated etc, the leakage has returned after just 10 miles and if it is what I think it is... at least there'll be some more content.So it's clear at this point there's an underlying problem.The injectors aren't sealing in the head, and the leaking combustion gas is killing injectors (I think it's done 3 so far, and refurbs are ~£135 each!). I've tried all kinds of vodoo magic and it's not right.It's slow to start and cuts out straight away sometimes, but otherwise all the data is fine. Boost is fine, DPF regens nicely, will cruise at speed, but despite that - it's down on power - it struggles to accelerate uphill. Of course this could be related to bad injectors, but...I asked for help and there was one rather worrying suggestion.The M57 engine was in production for over a decade with various revisions ("technical updates") along the way. Although the engine block is specific to a twin turbo, the heads are shared with other M57N2 (aka Technical Update 2) engines (e.g. E90 330d etc), which all use the same piezo injectors.However, it turns out that BMW re-used the older M57N (aka Technical Update 1) head with solenoid injectors as found on the older E46 etc and fitted it to an M57N2 engine to make 325d/525d engines. And the injector bores are slightly different to accommodate the different injectors.Without bragging, I'm usually pretty good at finding parts, cross-referencing part numbers etc. But I had to double check.I still have the old head, so found the part number on the side I'd used to cross-reference in the first place.And comparing to what I fitted, it matches....except, that's not the part number. There is no part number on the head at all. The nearest is a sticker on the back of the head.Specifically, M57TUE2 = M57, Technical Update 2.This was the nearest picture I had from when the engine was out, the sticker is obscured by a cover.I was just about able to get a picture down the back of the engine.M57T E4. Which is not techni