Does start/stop cause rod bearing failure?

Feddersen · 05-12-2019, 03:02 AM

I myself have had the rod bearing failure and needed a new engine and I have spoken to other who had the same issue. After the last chat to a guy with the rod failure problem in a N54 I searched for more information and found that BMW started to make an “IROX coating” in N63 and B58 engines and BMW states the following:

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Name: irox.JPG
Views: 1310
Size: 172.4 KB

Look for the full text in the technical training docs: https://f30.bimmerpost.com/forums/at...0&d=1441950445

The rod bearings used in N54/N55 have been used since the time before the start/stop-mechanism but apparently the start/stop causes excessive wear. Frequent oil changes apparently does not make that much of a difference since it is the lack of lubrication during the stop that is the problem.
Luckily I turn of the start/stop quite often but I am now going to remove it by coding.

JuiceQuadre · 05-12-2019, 03:28 AM

First thing i did to my car was code this out... No benefits only trouble imho.

Polo08816 · 05-12-2019, 08:45 AM

Quote:

Originally Posted by Feddersen

I myself have had the rod bearing failure and needed a new engine and I have spoken to other who had the same issue. After the last chat to a guy with the rod failure problem in a N54 I searched for more information and found that BMW started to make an “IROX coating” in N63 and B58 engines and BMW states the following:

Attachment 2051492

Look for the full text in the technical training docs: https://f30.bimmerpost.com/forums/at...0&d=1441950445

The rod bearings used in N54/N55 have been used since the time before the start/stop-mechanism but apparently the start/stop causes excessive wear. Frequent oil changes apparently does not make that much of a difference since it is the lack of lubrication during the stop that is the problem.
Luckily I turn of the start/stop quite often but I am now going to remove it by coding.

+1. I disabled this on my 14 F30 335i and the 16 X3 35i immediately. It's not that useful on a 6 cylinder engine - you can definitely feel the engine starting back up.

outofphase · 05-12-2019, 02:13 PM

I too have mine coded off but this IROX coating business is interesting to me. From what I've read the N55 (and BMW motors in general) have pretty tight rod bearing clearances from factory. Most of the rod bearing failure cases I've read about there's no mention at all of the start/stop function playing any role, but IMO there's no point risking it.

EDWYER · 05-12-2019, 06:58 PM

Quote:

Originally Posted by JuiceQuadre

First thing i did to my car was code this out

Same.

05-12-2019, 03:02 AM	#1
Feddersen Lieutenant 451 Rep 469 Posts Drives: X1 xDrive25i Join Date: Jan 2015 Location: Denmark iTrader: (0)	Does start/stop cause rod bearing failure? I myself have had the rod bearing failure and needed a new engine and I have spoken to other who had the same issue. After the last chat to a guy with the rod failure problem in a N54 I searched for more information and found that BMW started to make an “IROX coating” in N63 and B58 engines and BMW states the following: Look for the full text in the technical training docs: https://f30.bimmerpost.com/forums/at...0&d=1441950445 The rod bearings used in N54/N55 have been used since the time before the start/stop-mechanism but apparently the start/stop causes excessive wear. Frequent oil changes apparently does not make that much of a difference since it is the lack of lubrication during the stop that is the problem. Luckily I turn of the start/stop quite often but I am now going to remove it by coding. __________________ DD: F48 X1 xDrive25i '20 - https://f48.bimmerpost.com/forums/sh....php?t=1703083 For fun: F22 M240i '19 - https://www.2addicts.com/forums/show....php?t=1644646 Previous BMW: Fully loaded F30, 335i https://f30.bimmerpost.com/forums/sh....php?t=1681247
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05-12-2019, 03:28 AM	#2
JuiceQuadre Second Lieutenant 54 Rep 222 Posts Drives: E92 335D 2006, F30 335i 2014 Join Date: Oct 2016 Location: EU iTrader: (0)	First thing i did to my car was code this out... No benefits only trouble imho.
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05-12-2019, 02:13 PM	#4
outofphase dad bod 389 Rep 382 Posts Drives: 2015 335i xDrive Join Date: Feb 2019 Location: Chicago, IL iTrader: (1)	I too have mine coded off but this IROX coating business is interesting to me. From what I've read the N55 (and BMW motors in general) have pretty tight rod bearing clearances from factory. Most of the rod bearing failure cases I've read about there's no mention at all of the start/stop function playing any role, but IMO there's no point risking it. __________________ '15 F30 Estoril Blue 335i xDrive \| 8HP \| Stock Turbo \| 420 awhp / 451 awtq \| 11.85 @ 115 mph E30 JordanTuned on BM3 \| XDI-60 HPFP \| Fuel-It! lines + sensor \| VRSF FBO \| GFB DV+ \| XHP \| Vörsteiner VFF-107s \| Dinan Springs
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