Problems after new plugs installed

Dan_Q · 02-16-2016, 08:24 AM

Two days ago I replaced my plugs for general maintenance purposes. It had been almost 15k miles since I last did them. This time I used NGK 5992 (part number is now 95770). I adjusted the gap to 0.80 mm.

Took the car for a spin post install and everything was fine. Drove the car to work yesterday and everything was fine (~10 mi). Drove home and after about 8 mi the car began having major stuttering. I was cruising at constant speed with minimal throttle at the time it began. The car proceeded to have major stuttering the remaining 2 miles home and I checked codes this morning. All were misfire/miss related on multiple cylinders.

The plugs would be the obvious culprit but I'm re-reading the posts that pointed me to the NGK plugs in the first place and it certainly appears that lots of people have used them with success. Any thoughts on what could be the problem? I cleared the codes and will try logging this morning and rechecking codes to see what happens. Ironically, the last time I swapped plugs I also had a problem and that one resulted in needing a DME update at the dealer.

Also, the car has 47k miles on it. If I encounter the same problem this morning I plan to just head to the dealer to get a set of OEM plugs and try them. Should I also be getting new coil packs?

mbanks21 · 02-16-2016, 08:43 AM

I'd guess one (or more) weren't seated properly, or maybe the coil wasn't properly plugged back in.

weehe126 · 02-16-2016, 10:45 AM

double check all the plugs are torqued properly.

Dan_Q · 02-16-2016, 10:54 AM

Quote:

Originally Posted by mbanks21

I'd guess one (or more) weren't seated properly, or maybe the coil wasn't properly plugged back in.

This may have fixed it. I quickly pulled off all the hardware and re-engaged the coils onto the plugs. I also sprayed down both sides of the harness connection and re-engaged them as well. Made sure that everything was positively engaged and it started up without hiccupping. No codes. Made it 10 mi to work with no issues. Will check the log later but it may have been as simple a fix as this. THANKS! Lesson learned.

Cory S · 02-17-2016, 12:57 AM

Changing an Iridium tipped plug at 15K miles? Iridums are good for 45-60K even on a N54/N55.

Mine have 54K on them now, and never skips a beat.

02-16-2016, 08:24 AM	#1
Dan_Q Second Lieutenant 134 Rep 242 Posts Drives: F80 M3, F15 X5 50i Join Date: Feb 2011 Location: Colorado Front Range iTrader: (5) Garage List 2015 X5 xDrive50i [10.00] 2018 M3 [9.66]	Problems after new plugs installed Two days ago I replaced my plugs for general maintenance purposes. It had been almost 15k miles since I last did them. This time I used NGK 5992 (part number is now 95770). I adjusted the gap to 0.80 mm. Took the car for a spin post install and everything was fine. Drove the car to work yesterday and everything was fine (~10 mi). Drove home and after about 8 mi the car began having major stuttering. I was cruising at constant speed with minimal throttle at the time it began. The car proceeded to have major stuttering the remaining 2 miles home and I checked codes this morning. All were misfire/miss related on multiple cylinders. The plugs would be the obvious culprit but I'm re-reading the posts that pointed me to the NGK plugs in the first place and it certainly appears that lots of people have used them with success. Any thoughts on what could be the problem? I cleared the codes and will try logging this morning and rechecking codes to see what happens. Ironically, the last time I swapped plugs I also had a problem and that one resulted in needing a DME update at the dealer. Also, the car has 47k miles on it. If I encounter the same problem this morning I plan to just head to the dealer to get a set of OEM plugs and try them. Should I also be getting new coil packs? Last edited by Dan_Q; 02-16-2016 at 08:34 AM..
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02-16-2016, 08:43 AM	#2
mbanks21 Colonel 1281 Rep 2,962 Posts Drives: 2015 335i MSport Join Date: Aug 2013 Location: High Bridge, NJ iTrader: (8)	I'd guess one (or more) weren't seated properly, or maybe the coil wasn't properly plugged back in.
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02-16-2016, 10:45 AM	#3
weehe126 Brigadier General 1189 Rep 3,228 Posts Drives: 2017 340i Join Date: Apr 2014 Location: San Antonio iTrader: (2)	double check all the plugs are torqued properly.
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02-17-2016, 12:57 AM	#5
Cory S Major 306 Rep 1,163 Posts Drives: 2011 335i-X Join Date: Oct 2015 Location: N.H. iTrader: (0)	Changing an Iridium tipped plug at 15K miles? Iridums are good for 45-60K even on a N54/N55. Mine have 54K on them now, and never skips a beat.
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