N54: The best Plugs, Injectors and Coils Thread

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doublespaces

Administrator
Oct 18, 2016
6,684
AZ
#1
Okay its gotten to that point where the influx of newcomers to the platform is rapidly rising and there are several common questions that get asked repeatedly and this will focus on a few maintenance items. For the sanity of the veterans to the platform, it is nice to have threads like these to reference. This post will hopefully answer some of those questions and I will update this as much as possible as information evolves. Lets get to it:

Spark Plugs (Thanks to @[email protected] for this info)

A lot of people are going to want the N20 plug, which is the NGK 97506. If you don't want to go two steps colder, you can use the S55/N55 equivalent plug, the 95770 which is just 1 step colder than N54 stock.

Here is a long thread discussing the two:
https://bmw.spoolstreet.com/threads/plugs-95770-v-97506-gaps-and-the-n54.3718/

There are slight variations to the NGK part numbers which substitute the D for C and E, for example: SILZKBR8D8S which may relate to the thread reach. See below for an explanation of what each letter represents.

[TABLE="class: brtb_item_table"][TBODY][TR][TD]BOSCH ZGR6STE2[/TD][TD]Identical to OE and cheaper[/TD][/TR]
[TR][TD]NGK 95770 (ILZKBR7B8DG) (5992) (ILZKBR7A-8G)[/TD][TD]1 Step Colder (FBO+) (N55) (S55)[/TD][/TR]
[TR][TD]NGK 97506 (SILZKBR8D8S)(12120039664)[/TD][TD]2 Steps Colder (N20)[/TD][/TR]
[TR][TD]NGK SILZKBR9F8S[/TD][TD]3 Steps Colder (N20 Flex Fuel)[/TD][/TR][/TBODY][/TABLE]
How to read NGK plug codes(positions from the right):
The typical designation is as follows:

  • The letter combination (1-4) before the heat rating indicates the thread diameter, hexagon spanner width and the design.
  • The 5th position (number) stands for the heat rating.
  • The 6th letter identifies the thread length.
  • The 7th letter contains data about special spark plug construction features.
  • The 8th position, another number, codifies special electrode distances.
Now lets talk gapping.
I see a lot of people running into ignition issues swearing they gapped the plugs correctly. Wire and the round disks you get from AZ or advanced are all junk. I use either “feeler gauges” or a razor blade that I used a micrometer with to verify thickness. There should be a slight resistance as you insert the feeler gauge between the electrode and ground. If it goes in really easy or its tough to get in then its not gapped correctly. Take your time and do it right the first time.

Recommended gaps are

[TABLE="class: brtb_item_table"][TBODY][TR][TD]0.022”[/TD][TD]0-25psi (pump to E50 with meth)[/TD][/TR]
[TR][TD]0.018”[/TD][TD]25+psi (pump to E50 with meth)[/TD][/TR]
[TR][TD]0.018”[/TD][TD]20+psi (E85)[/TD][/TR][/TBODY][/TABLE]
That’s been my experience with fresh coils. Others may have better or worst luck.

Injectors
There have been several revisions to the injectors over the years with Index 12 being the most recent at the time of writing and seemingly the most reliable. There are many places to get these injectors for a significant discount over OE sources, which I will leave up to you to locate. It is important for various reason to ensure all six injectors are replaced at the same time with the same type. You can mix and match Index 11 and 12 injectors with the correct coding, however you may experience bank variances.

One additional bit of information is in regards to injectors is an extended warranty for certain build dates. See below if you qualify for reimbursement:

SI B01 02 15

E60 (535i Sedan and 535i xDrive Sedan)
Model Year 2010 produced 1/21/2009 to 12/17/2009

E61 (535i xDrive Sports Wagon)
Model Year 2010 produced 2/18/2009 to 3/30/2010

E71 (X6 xDrive35i)
Model Year 2010 produced 6/10/2009 to 3/18/2010

E82 (135i Coupe)
Model Year 2010 produced 8/13/2009 to 2/26/2010

E88 (135i Convertible)
Model Year 2010 produced 7/22/2009 to 2/26/2010

E89 (Z4 sDrive35i)
Model Years 2010 and 2011 produced 8/31/2009 to 8/30/2011

E90 (335i Sedan and 335i xDrive Sedan)
Model Year 2010 produced from 4/23/2009 to 2/25/2010

E92 (335i Coupe and 335i xDrive Coupe)
Model Year 2010 produced 7/27/2009 to 02/26/2010

E93 (335i Convertible)
Model Year 2010 produced 8/29/2009 to 2/25/2010

F01 (740i Sedan)
Model Years 2011 and 2012 produced 11/16/2009 to 6/20/2012

F02 (740Li Sedan LWB)
Model Years 2011 and 2012 produced 2/18/2010 to 6/20/2012

With the N54 engine

For the above-referenced vehicles, BMW of North America, LLC (“BMW NA”) is extending the limited warranty for the fuel injectors to:

10 years/120,000 miles as determined by the vehicle’s original in-service date

This bulletin is notice of a “limited warranty extension.” This is NOT a notice of a Recall or Service Action.

For a customer to request reimbursement for a “qualifying customer-pay repair” performed either by an authorized BMW center or independent repair shop located in the United States (including Puerto Rico), please have him/her submit his/her reimbursement request “online” at www.BMW-RP.com .

Alternative Method to Request Reimbursement
Mail or fax your request and documentation to:
BMW Customer Reimbursement Center
Attention: B-ELWR 2015 Fuel Injectors 10Y120M
P.O. Box 561089
Dallas, Texas 75356
Fax number: 877-434-2992
Please allow 4-6 weeks for processing your request.
Should you have any questions concerning this reimbursement process, please call 1-844-857-0341.
For all other questions, please contact the BMW’s Customer Relations and Services via email at [email protected] or via telephone at 1-800-831-1117.
Please have your 17-character Vehicle Identification Number (VIN) available and include the VIN with all communications.

Coils
Anyone purchasing new OE coils should wind up getting the new design with the metal housing from Eldor which seem to be a solid choice. There have been a few performance oriented coils such as the Okada Plasma Direct, however its been said that there are better ways to spend that money. There are also many people running the N55 coils by Delphi.

Eldor #12138657273
Delphi GN10571

Upgraded Coils
There are currently two upgraded coil offerings:
[TABLE="class: brtb_item_table"][TBODY][TR][TD]BimmerLife Tuning[/TD][TD]Smart Coil[/TD][/TR]
[TR][TD]Precision Raceworks[/TD][TD]Dumb Coil[/TD][/TR][/TBODY][/TABLE]
https://bmw.spoolstreet.com/threads/my-review-for-the-bimmerlife-coil-upgrade.1963/
https://bmw.spoolstreet.com/threads/ignition-coil-comparison-primary-energy.1613/
https://bmw.spoolstreet.com/threads/vtt-precision-raceworks-coil-install-results-thread.1838/


If any of this information is out of date, incomplete or incorrect please notify me and I will revise it.
 

Dere[email protected]

Lieutenant
Free Vendor
Nov 14, 2016
653
North Wilkesboro
#2
Sweet thread, I am replacing sparks and coils soon.

I'd love the peace of mind knowing my injectors aren't going to go... but, index 12s are EXPENSIVE lol

Can you explain the term "colder" (might sound nooby here) I understand that it means the gap difference is different but, why the term "colder"
 
Last edited:
Nov 20, 2016
260
ATL ga
#3
The spark is not as hot and the idea is that it can be advanced without being hot enough to cause pre ignition / detonation and therefore timing corrections etc
 
Dec 1, 2016
79
Texas
#4
Is it okay to use one Delph coil and rest with OEM? My one cylinder is off atm and need to replace it soon
 

Cheezy

Lieutenant
Nov 7, 2016
552
Toledo Ohio
#5
Is it okay to use one Delph coil and rest with OEM? My one cylinder is off atm and need to replace it soon
Coils can be mismatched. I still like Bosch over Delphi, the boot seems tougher and if they break around the sparkplug it's a pain.
 

Bmac

Specialist
Nov 8, 2016
72
Great White North
#7
I don't agree there is any consensus on "best" coils. Some people like Bosch, some Eldor, some Delphi. Unless a coil lasts longer, gives better fuel economy, increases power or just costs less how could one be any better then another? They all perform the exact same function. Bosch seem to be the cheapest and are proven to have decent longevity, Eldor is what BMW is using now instead of Bosch and Delphi is just an alternative to the OEM coils. I don't think something should be declared the best without any rationale or metric explaining why.
 

doublespaces

Administrator
Oct 18, 2016
6,684
AZ
#8
I don't agree there is any consensus on "best" coils. Some people like Bosch, some Eldor, some Delphi. Unless a coil lasts longer, gives better fuel economy, increases power or just costs less how could one be any better then another? They all perform the exact same function. Bosch seem to be the cheapest and are proven to have decent longevity, Eldor is what BMW is using now instead of Bosch and Delphi is just an alternative to the OEM coils. I don't think something should be declared the best without any rationale or metric explaining why.
This was just the conclusion I came to myself after researching. I've heard about several issues with the boot on the bosch suffering from heat cycling. I think there wasn't a lot of information on the eldor at the time, I've included them in the list.
 
Nov 5, 2016
107
Kansas
#9
So I tried the autolite 5682... no bueno, my ngks work great but the autolites throw me into limp for misfires like crazy.. gapped correctly. Do we know a stock heat range ngk plug? Or stock heat that's not a triple electrode?
 

[email protected]

Lieutenant
Free Vendor
Nov 14, 2016
653
North Wilkesboro
#10
So I tried the autolite 5682... no bueno, my ngks work great but the autolites throw me into limp for misfires like crazy.. gapped correctly. Do we know a stock heat range ngk plug? Or stock heat that's not a triple electrode?
I was gonna try out Autolites, bought them. Took them back. Got NGK 95770 and gapped to .022

Car runs beautifully and hasn't had any issues yet
 

V8bait

Sergeant
Nov 2, 2016
328
Texas
#11
I think the 2 step colder plugs should be used for everybody who is tuned, I haven't heard of any fouling issues with them, so they aren't too cold.
 

[email protected]

Lieutenant
Free Vendor
Nov 14, 2016
653
North Wilkesboro
#12
I think the 2 step colder plugs should be used for everybody who is tuned, I haven't heard of any fouling issues with them, so they aren't too cold.
Maybe true but, for the most part for the applications a Stage 1+ tuner would need. could easily be supported by OEM replacements, or 1 step colder. That's like saying:

"I don't understand why anyone with a tuned car doesn't get a Stage 2 LPFP!" at the end of the day... Yes, it would be better anyways but, is it needed for their given setup?
 
Nov 5, 2016
107
Kansas
#13
So talking to my big hp buddies 1000+ and their tuners they are adamant on running stock heat range even with E85, at most one step colder i.e. Ngk 95770.. do we know of any plugs other than the OE Bosch ones with their heat range that'd work?
 

doublespaces

Administrator
Oct 18, 2016
6,684
AZ
#14
Maybe true but, for the most part for the applications a Stage 1+ tuner would need. could easily be supported by OEM replacements, or 1 step colder. That's like saying:

"I don't understand why anyone with a tuned car doesn't get a Stage 2 LPFP!" at the end of the day... Yes, it would be better anyways but, is it needed for their given setup?
What is the price difference between the two? If they work and cost similar, may as will go 2 steps. If they cost more then I suppose there is a debate, though I can't imagine they would cost much more.
 

V8bait

Sergeant
Nov 2, 2016
328
Texas
#16
What is the price difference between thw two? I'd if they work and cost similar, may as will go 2 steps. If they cost more then I suppose there is a debate, though I can't imagine they would cost much more.
Exactly. N55 and S55 are 2 steps colder than OEM to begin with iirc. Heat ranges aren't a very big deal unless you're too hot or too cold, but too hot can be bad. Too cold can misfire and foul if you put around town for short trips and the engine never even gets up to temp, but too hot can cause knock. Since the cars seem to do fine with 2 steps colder I don't see a downside since cost is similar, maybe someone knows more about it though. This is just how I've always approached heat index.
 
Nov 5, 2016
107
Kansas
#17
On E85 blends you shouldn't have knock running a stock heat range plug, I'm not saying run the oem Bosch ones, but a replacement which I have yet to find aside from Champion Coppers these should work great but you'd need to change them every oil change. (Only like $2 or so a plug) I'd like to find some ngk iridiums with stock heat range to last a bit longer, if not I'll keep the 1 step colder.. there's no need to run 2 steps colder, you won't make any extra power, and just run the higher misfire and fouling rates.. and lower mpg

N55 plugs are 1 step colder than n54 stock for stock. The 95770 ngks are a stock alternative for n55
 

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