intermittent cylinder 6 misfire (help)

PNWBimmer6578 · 10-23-2023, 07:24 PM

I have been having WOT high rpm misfires only on cylinder 6. Service engine soon light comes on and I have to restart the car because it feels like it is only firing on the other 5 cylinders. I have switched the coils, plugs and injectors with cylinder 5 and I still get the misfire on cylinder 6. Any ideas on what else to test/replace?

Bosch coil packs 6k miles ago
Step 2 colder plugs at a 0.22 gap 2k miles ago
Index 12 injectors 20k ago
Valve cleaning 5k miles ago

CLEAN13BOOSTED · 10-23-2023, 08:05 PM

Understanding components have been switched with #5 and the misfire still follows #6. Does restarting correct the misfire or does the misfire re-occur every time at higher rpm after the ignition has been cycled? Have the coil and injector circuits been inspected/tested?

PNWBimmer6578 · 10-23-2023, 08:18 PM

The misfire only happens sometimes only at wot. It goes away after restarting but can come back if you go full throttle

CLEAN13BOOSTED · 10-23-2023, 09:00 PM

With an intermittent misfire at WOT I would inspect the connectors for terminal tension at the coil and injector. With the engine running at idle wiggle test the circuits as close to the connectors as possible and see if you're able to induce the misfire. Assuming misfires codes are setting?

10-23-2023, 07:24 PM	#1
PNWBimmer6578 New Member 71 Rep 18 Posts Drives: 2009 E92 335i Join Date: Mar 2023 Location: Washington iTrader: (0) Garage List 2009 E92 335i [0.00]	intermittent cylinder 6 misfire (help) I have been having WOT high rpm misfires only on cylinder 6. Service engine soon light comes on and I have to restart the car because it feels like it is only firing on the other 5 cylinders. I have switched the coils, plugs and injectors with cylinder 5 and I still get the misfire on cylinder 6. Any ideas on what else to test/replace? Bosch coil packs 6k miles ago Step 2 colder plugs at a 0.22 gap 2k miles ago Index 12 injectors 20k ago Valve cleaning 5k miles ago
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10-23-2023, 08:05 PM	#2
CLEAN13BOOSTED Private First Class 74 Rep 104 Posts Drives: 2013 BMW E93 3351 Join Date: Oct 2023 Location: FLORIDA iTrader: (0)	Understanding components have been switched with #5 and the misfire still follows #6. Does restarting correct the misfire or does the misfire re-occur every time at higher rpm after the ignition has been cycled? Have the coil and injector circuits been inspected/tested? Last edited by CLEAN13BOOSTED; 10-23-2023 at 08:14 PM.. Reason: updated diagnostic notes.
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10-23-2023, 08:18 PM	#3
PNWBimmer6578 New Member 71 Rep 18 Posts Drives: 2009 E92 335i Join Date: Mar 2023 Location: Washington iTrader: (0) Garage List 2009 E92 335i [0.00]	The misfire only happens sometimes only at wot. It goes away after restarting but can come back if you go full throttle
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10-23-2023, 09:00 PM	#4
CLEAN13BOOSTED Private First Class 74 Rep 104 Posts Drives: 2013 BMW E93 3351 Join Date: Oct 2023 Location: FLORIDA iTrader: (0)	With an intermittent misfire at WOT I would inspect the connectors for terminal tension at the coil and injector. With the engine running at idle wiggle test the circuits as close to the connectors as possible and see if you're able to induce the misfire. Assuming misfires codes are setting?
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