Misfire at Wot

F80_M3llow · 06-09-2013, 10:39 AM

Hi everyone I need some help diagnosing an issue I'm having with my n54. The engine has 40k miles. plugs where never changed coil also where never touched. No tunes just stock. I'm getting a stumbling misfire at high rpm and on open throttle. The car jerks back and forth and keeps going. I ran some tests on the coils and got. 4.44, 4.88, 5.19, 4.46, 5.48, and 4.77 OHMs. If anyone can tell me if these readings are ok. Thanks

BlackBB6 · 06-09-2013, 10:47 AM

The plugs are due at 45k anyways, might as well replace them now. The recommended interval is 15k for tunes, so I could see 40k miles of spirited driving wearing them out with no tune.

AndyR83 · 06-09-2013, 10:59 AM

Yeah, I have a similar issue. I just ordered a set of plugs a second ago.

F80_M3llow · 06-09-2013, 11:12 AM

Quote:

Originally Posted by AndyR83

Yeah, I have a similar issue. I just ordered a set of plugs a second ago.

Let me know how it turns out. I'm just going to go ahead and do plugs on Tuesday. Coils look fine no cracks and signs of wear.

F80_M3llow · 06-09-2013, 11:13 AM

Quote:

Originally Posted by BlackBB6

The plugs are due at 45k anyways, might as well replace them now. The recommended interval is 15k for tunes, so I could see 40k miles of spirited driving wearing them out with no tune.

Yeah I'm going to go ahead and do the plugs. It's highly upsetting be because I have my jb4 waiting to get put in and now this happens.

F80_M3llow · 09-16-2013, 07:47 PM

sorry for the long update. i had a fouled plug at cylinder six. Changed all the plugs and she runs like new. thanks for all the help

3000GT MR · 09-16-2013, 07:51 PM

FWIW i got approx 3.8x ohms across the primary on both a good and a known bad coil. Like suggested above start with plugs. It's time for them regardless.

Hokie_BMW · 09-16-2013, 09:38 PM

I had this issue with my tune. Had some inconsistent power and slight jerking at WOT. Ended up being my coils. I had the issue then about 200 miles later the cylinder 1 coil failed. Replaced it and everything was good. Then it happened again the other day which makes me think I have another going.

06-09-2013, 10:39 AM	#1
F80_M3llow Lieutenant Colonel 201 Rep 1,714 Posts Drives: 2011 335i Join Date: Apr 2008 Location: Norwalk CT iTrader: (14) Garage List 2016 BMW M3 [9.00] 2008 135i [7.00]	Hi everyone I need some help diagnosing an issue I'm having with my n54. The engine has 40k miles. plugs where never changed coil also where never touched. No tunes just stock. I'm getting a stumbling misfire at high rpm and on open throttle. The car jerks back and forth and keeps going. I ran some tests on the coils and got. 4.44, 4.88, 5.19, 4.46, 5.48, and 4.77 OHMs. If anyone can tell me if these readings are ok. Thanks
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06-09-2013, 10:47 AM	#2
BlackBB6 Lieutenant 65 Rep 554 Posts Drives: E92 335i 6MT Join Date: Oct 2011 Location: Dallas iTrader: (2) Garage List 2008 BMW E92 335i [8.00]	The plugs are due at 45k anyways, might as well replace them now. The recommended interval is 15k for tunes, so I could see 40k miles of spirited driving wearing them out with no tune.
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06-09-2013, 10:59 AM	#3
AndyR83 Major 60 Rep 1,024 Posts Drives: E92 335i FBO Join Date: Oct 2011 Location: PA iTrader: (5)	Yeah, I have a similar issue. I just ordered a set of plugs a second ago. __________________ Do NOT do business with IAN HAAN, aka n54bewst, aka 747tuned aka H17M3, a scammer who STILL has an account here on e90post!
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09-16-2013, 07:47 PM	#6
F80_M3llow Lieutenant Colonel 201 Rep 1,714 Posts Drives: 2011 335i Join Date: Apr 2008 Location: Norwalk CT iTrader: (14) Garage List 2016 BMW M3 [9.00] 2008 135i [7.00]	sorry for the long update. i had a fouled plug at cylinder six. Changed all the plugs and she runs like new. thanks for all the help
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09-16-2013, 07:51 PM	#7
3000GT MR Major 265 Rep 1,392 Posts Drives: 09 335i/3000gt vr4 Join Date: Jun 2012 Location: Sav GA iTrader: (6)	FWIW i got approx 3.8x ohms across the primary on both a good and a known bad coil. Like suggested above start with plugs. It's time for them regardless. __________________ Have a single turbo and/or tired of burning up O2 sensors? Ask me about the new ADV O2 sensor retro kits! 335i 2010 e92 M-sport Mods: VM Top mount 6466, Aquamist HSF4 w/custom direct port. VRSF IC + Exhaust 335i 2009 e90 665RWHP VFF900 ST RIP .
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09-16-2013, 09:38 PM	#8
Hokie_BMW Captain 59 Rep 661 Posts Drives: 2009 335i Sedan Join Date: Apr 2013 Location: NC iTrader: (0)	I had this issue with my tune. Had some inconsistent power and slight jerking at WOT. Ended up being my coils. I had the issue then about 200 miles later the cylinder 1 coil failed. Replaced it and everything was good. Then it happened again the other day which makes me think I have another going.
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