N54 (E92) Spark Plugs/Coils bad every 6-7k miles

speedbee13

Private
Dec 13, 2021
29
1
5
0
Wake Forest, NC
Ride
2010 BMW 335i e92
Hello all, first forum post so I hope I do this right. Got my car in April this year(2010 BMW 335i e92), and it currently has 70k miles.

Mods:
VRSF Dual Cone Intake
Upgraded Chargepipe
VRSF 7.5" Intercooler
BMS Oil Cooler Valve

Maintenance:
Valve Cover Gasket 65k miles
Oil change when I got the car(62k), 65k miles, and 70k miles
Plugs: 63k miles, second set of plugs in between 65 and 67k(replaced 1 by 1 as they went out), 70k miles(NGK 97968
Coils: 63k miles, second set of coils in between 65 and 67k(replaced 1 by 1 as they went out)
Injectors: Replaced with new(I assume) Index 12 sometime before I bought the car(Leak tested yesterday)

Tune: MHD Stage 1+ 93oct

I replaced plugs and coils so often because of misfires during driving and during cold starts. Right now no issues but it's only been 500 miles or so since plugs were replaced, and only other thing I've noticed is oil temp has dropped to around 190-200* while driving normal since I put the new oil cooler valve in, but that's the point of it. Any idea why my plugs/coils keep fouling out?
 
Solution
Arcing? Not familiar with that. I would do logs but I dont have the log license and can't buy it right now. I bought from fcpeuro and replace all at the same time.
Spark plugs fire at insane voltages, and sometimes the spark can travel thru the coil boot. You'll notice tell tail signs of that on the porcelain part of the plug. Can cause damage to coil or plug. Dielectric grease helps prevent that from happening. People have differing opinions on whether the grease is necessary, but I've always used it. It goes in the coil boot where it meets the porcelain.

corbanistan

Specialist
Jul 26, 2021
91
1
42
0
Florida, USA
Ride
E93 335i 6MT
I just looked it up real quick, so having yellow on the ceramic(I assume burnt ceramic) means I likely have arcing?
Yes definitely start with dielectric grease. Pull your plugs and while you're at it double check gap, and apply the grease. Then torque them back to spec. These engines can be very particular.
 

speedbee13

Private
Dec 13, 2021
29
1
5
0
Wake Forest, NC
Ride
2010 BMW 335i e92
Yes definitely start with dielectric grease. Pull your plugs and while you're at it double check gap, and apply the grease. Then torque them back to spec. These engines can be very particular.
Just looked at my old plugs and they don't look really burnt which I thought they were. The two plugs on the right which are blacker, the ceramic and the tip where the gap is spins freely separate from the metal. Any ideas?
 

corbanistan

Specialist
Jul 26, 2021
91
1
42
0
Florida, USA
Ride
E93 335i 6MT
Just looked at my old plugs and they don't look really burnt which I thought they were. The two plugs on the right which are blacker, the ceramic and the tip where the gap is spins freely separate from the metal. Any ideas?
No part of the plug besides the washer should be loose, that's interesting. Do you have a photo of it?
 

speedbee13

Private
Dec 13, 2021
29
1
5
0
Wake Forest, NC
Ride
2010 BMW 335i e92
No part of the plug besides the washer should be loose, that's interesting. Do you have a photo of it?
I thought the photo uploaded, my bad. The two plugs on the right the ceramic part spins, they also have a noticeably blacker spot on the ceramic
20211216_191748.jpg
 

speedbee13

Private
Dec 13, 2021
29
1
5
0
Wake Forest, NC
Ride
2010 BMW 335i e92
That's not supposed to happen. What tune are you running? Any oil around the spark plug wells?
I didn't realize they spun until i went to check for arcing on the old ones. It is possible there is a slight amount of oil around the wells as I haven't tried to rub them, but there isn't any that I've noticed. I currently run MHD's stage 1+ 93oct. Boost setpoint for it is 16psi and my gap is .022
 

corbanistan

Specialist
Jul 26, 2021
91
1
42
0
Florida, USA
Ride
E93 335i 6MT
I didn't realize they spun until i went to check for arcing on the old ones. It is possible there is a slight amount of oil around the wells as I haven't tried to rub them, but there isn't any that I've noticed. I currently run MHD's stage 1+ 93oct. Boost setpoint for it is 16psi and my gap is .022
Hopefully someone else can also chime in on this, but those 2 plugs don't seem good if the porcelain spins like that. Never seen that before. I'd get new plugs, use dielectric grease, torque to spec. Make sure everything else is clean. Run that until it happens again or hopefully never does
 

speedbee13

Private
Dec 13, 2021
29
1
5
0
Wake Forest, NC
Ride
2010 BMW 335i e92
Hopefully someone else can also chime in on this, but those 2 plugs don't seem good if the porcelain spins like that. Never seen that before. I'd get new plugs, use dielectric grease, torque to spec. Make sure everything else is clean. Run that until it happens again or hopefully never does
Yeah i didn't even know the ceramic could spin like that. It also spins
the white piece that has the tip for spark. I have brand new ngk plugs already and i will put grease on this weekend.
On another note, detonation can cause the porcelain to come loose.
Interesting, do you think misfires could also cause it to some loose(I'm not sure if misfires are detonation, im kinda dumb)
 

SLOWESTN54

Lieutenant
Feb 9, 2021
697
435
0
22
B.C. Canada
Ride
2007 E92 335i / 2008 E60 535i
nothing looked mad when monitoring all temps, boost, knock degrees, and timing
I dont have the log license and can't buy it right now
Logging is including with your MHD monitoring license.

Check if your valve cover gasket isn't leaking into the Cylinders, Also check your Coil grounds on your valve cover, Make sure the stud is tight as well.
 

speedbee13

Private
Dec 13, 2021
29
1
5
0
Wake Forest, NC
Ride
2010 BMW 335i e92
Logging is including with your MHD monitoring license.

Check if your valve cover gasket isn't leaking into the Cylinders, Also check your Coil grounds on your valve cover, Make sure the stud is tight as well.
I don't have the monitoring license. I monitor everything in a separate free app for now. My valve cover has 2 broken bolts(alluminum pos bolts) but isn't leaking from what I can see. Want to replace them but I feel like I could possibly break another if I remove them and put new ones in(broken bolts got stuck half in there), so I am waiting until I can buy all 28 bolts. I'm fairly new to working on N54(plus I'm dumb lol), so I need to look up the coil grounds.
 

SLOWESTN54

Lieutenant
Feb 9, 2021
697
435
0
22
B.C. Canada
Ride
2007 E92 335i / 2008 E60 535i
I don't have the monitoring license. I monitor everything in a separate free app for now. My valve cover has 2 broken bolts(alluminum pos bolts) but isn't leaking from what I can see. Want to replace them but I feel like I could possibly break another if I remove them and put new ones in(broken bolts got stuck half in there), so I am waiting until I can buy all 28 bolts. I'm fairly new to working on N54(plus I'm dumb lol), so I need to look up the coil grounds.
If you look at your valve cover cover, and follow the wiring for the coils, there will be 3 wires (1 wire per 2 coils). These wires go to a stud that also acts ass a valve cover bolt.


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