help with misfire during dyno

f87.lci · 07-04-2016, 09:23 AM

Hey guys,

I recently dyno-ed the car( May 2016) and although it made decent tq (392 wtq), it did not make peak hp as it started to misfire ( see graph). I was told that the car had misfires on cyl 1 and 5. I have changed the plugs recently (5000km ago). I also had a misfire with cel going of in feb/16 and thats when the dealership replaced 1 ignition coil -cyl 4 ) and refused to change the others under CPO as they said that was the only faulty coil.

My problem is that I have been trying to replicate the misfire after the dyno to get the cel to get the coils changed under warranty, but have failed . I have tried doing some WOT runs and still nothing. Not sure if the codes were cleared, there is nothing in the history either. What is the best way to check if the car is misfiring?

Should i ignore the problem thinking that maybe something went wrong and it misfired during the dyno or take the bite and replace all the coils out of pocket as the dealer wont do anything until i get the cel. I am having a hard time determining if the car is misfiring or not. Thanks for any input and feedback.

2011 BMW 335xi (n55) with 73,000 km

Taskmaster · 07-04-2016, 10:04 AM

You can continue to put the car under load (think accelerating from a stop in 2nd/3rd) and that can usually cause the missfire to pop up. If it happens enough times, it will produce a shadow code - and then a CEL.

f87.lci · 07-04-2016, 12:41 PM

Thanks, will def try this

Cory S · 07-04-2016, 11:45 PM

Tighten the plug gaps to .020-.022"

f87.lci · 07-06-2016, 03:46 PM

Don't think it could be the plugs as they were changed by the dealership . I'm hoping they know how to tighten them haha

Peen · 07-06-2016, 09:46 PM

He's talking about the spark gap, nothing to do with putting in head.

07-04-2016, 09:23 AM	#1
f87.lci First Lieutenant 32 Rep 324 Posts Drives: 2018 BMW M2- 6MT Join Date: May 2014 Location: Mississauga iTrader: (0)	help with misfire during dyno Hey guys, I recently dyno-ed the car( May 2016) and although it made decent tq (392 wtq), it did not make peak hp as it started to misfire ( see graph). I was told that the car had misfires on cyl 1 and 5. I have changed the plugs recently (5000km ago). I also had a misfire with cel going of in feb/16 and thats when the dealership replaced 1 ignition coil -cyl 4 ) and refused to change the others under CPO as they said that was the only faulty coil. My problem is that I have been trying to replicate the misfire after the dyno to get the cel to get the coils changed under warranty, but have failed . I have tried doing some WOT runs and still nothing. Not sure if the codes were cleared, there is nothing in the history either. What is the best way to check if the car is misfiring? Should i ignore the problem thinking that maybe something went wrong and it misfired during the dyno or take the bite and replace all the coils out of pocket as the dealer wont do anything until i get the cel. I am having a hard time determining if the car is misfiring or not. Thanks for any input and feedback. 2011 BMW 335xi (n55) with 73,000 km Attached Images __________________ 2018 BMW M2 (LBB)\| 6MT\| \|MPE\| Vorsteiner VFF 107\| Vorsteiner CF Front Lip\| MP Winglets\|Evo Comp II Intercooler \|Fabspeed Sportcat Downpipe\| FTP Boost /Charge Pipes \|PT Turbo Inlet Pipe\| \|Turbosmart DV\| \|BM3 Stage 2 93 Tune\| \|BMW Electronic Wheel\|\|KW V3 Coilovers\| IG: https://www.instagram.com/f87lci/
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07-04-2016, 10:04 AM	#2
Taskmaster Banned 2465 Rep 9,004 Posts Drives: M235i 6MT / E92 328 Msport 6MT Join Date: Nov 2013 Location: Florida iTrader: (6)	You can continue to put the car under load (think accelerating from a stop in 2nd/3rd) and that can usually cause the missfire to pop up. If it happens enough times, it will produce a shadow code - and then a CEL.
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07-04-2016, 12:41 PM	#3
f87.lci First Lieutenant 32 Rep 324 Posts Drives: 2018 BMW M2- 6MT Join Date: May 2014 Location: Mississauga iTrader: (0)	Thanks, will def try this __________________ 2018 BMW M2 (LBB)\| 6MT\| \|MPE\| Vorsteiner VFF 107\| Vorsteiner CF Front Lip\| MP Winglets\|Evo Comp II Intercooler \|Fabspeed Sportcat Downpipe\| FTP Boost /Charge Pipes \|PT Turbo Inlet Pipe\| \|Turbosmart DV\| \|BM3 Stage 2 93 Tune\| \|BMW Electronic Wheel\|\|KW V3 Coilovers\| IG: https://www.instagram.com/f87lci/
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07-04-2016, 11:45 PM	#4
Cory S Major 305 Rep 1,163 Posts Drives: 2011 335i-X Join Date: Oct 2015 Location: N.H. iTrader: (0)	Tighten the plug gaps to .020-.022" __________________ 2011 335i X-drive 6AT / Pure turbo / 500AWHP/526TQ
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07-06-2016, 03:46 PM	#5
f87.lci First Lieutenant 32 Rep 324 Posts Drives: 2018 BMW M2- 6MT Join Date: May 2014 Location: Mississauga iTrader: (0)	Don't think it could be the plugs as they were changed by the dealership . I'm hoping they know how to tighten them haha
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07-06-2016, 09:46 PM	#6
Peen Private First Class 41 Rep 156 Posts Drives: 2011 BMW 335i Sedan Join Date: Dec 2015 Location: San Diego, CA iTrader: (0)	He's talking about the spark gap, nothing to do with putting in head. __________________ 2011 335i / MHD E85 BEF / JB4 ISO / xHP Stage 3 TCU / VRSF Catless DP / Phoenix CP / YCW Coilovers's 6K-18K / M3 Control Arms / Enkei Raijin 18' Wheels / Michellin PSS
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