Discovered I’ve been running mismatched injectors for 35k miles......

Phil G · 05-01-2018, 01:37 PM

Cylinder #1 stopped firing in my car a few days ago, and checked my injectors as part of the diagnosis. I ultimately found the cause was a dead coil pack, but when I checked the injectors I found that I’m running mismatched injectors!

I’ve been running the original index -01 injectors in cylinders #2-6 since I bought the car new 11 years/160k miles ago. However, I found out I am running an index -12 index injector in cylinder #1. An indy shop replaced it 3 years ago at around 125k miles when the injector in cylinder #1 blew. The shop owner (who has been working on BMWs for 35+ years) told me that he found a “close enough version” injector, and calibrated it himself so it would operate in sync with the older injectors.

I figured that he found an unused, older version injector, but I apparently misunderstood! The car has been running smoothly for 35k miles since then, and even on a JB4 in Map 5 for 25k miles! Should I consider this the work of a genius, or be concerned?

feuer · 05-01-2018, 02:52 PM

lol 35k without issues is self explanatory isn't it? Nothing wrong with running mixed injector indexes. Keep enjoying your 335i

MysticRob · 05-01-2018, 05:50 PM

Quote:

Originally Posted by feuer

lol 35k without issues is self explanatory isn't it? Nothing wrong with running mixed injector indexes. Keep enjoying your 335i

This also goes a long way toward putting to rest the idea from BMW's own literature about not mixing newer index 11 and above injectors with 10 and older.

Riceball777 · 05-01-2018, 08:15 PM

my injectors are also all different index and its been running fine for a long ass time.

IllSic_Design · 05-01-2018, 08:29 PM

Yeah I believe I have two 7s with all the rest 9s that I noticed about 20k ago. But my car has no issues so no need to worry unless as stated above you have 11 or higher index mixed with a lower set, or they weren't coded in when installed.

Jeff@TopGearSolutions · 05-01-2018, 08:36 PM

Quote:

Originally Posted by IllSic_Design

Yeah I believe I have two 7s with all the rest 9s that I noticed about 20k ago. But my car has no issues so no need to worry unless as stated above you have 11 or higher index mixed with a lower set, or they weren't coded in when installed.

Amazing you're still ok. Those are 2 of the most problematic revisions. Play the lottery

IllSic_Design · 05-01-2018, 09:11 PM

Quote:

Originally Posted by Jeff@TopGearSolutions

Amazing you're still ok. Those are 2 of the most problematic revisions. Play the lottery

Yes I know,

lol! I have been preparing for the need to change them but so far so good(knock on wood).

feuer · 05-01-2018, 10:32 PM

Quote:

Originally Posted by IllSic_Design

Yeah I believe I have two 7s with all the rest 9s that I noticed about 20k ago. But my car has no issues so no need to worry unless as stated above you have 11 or higher index mixed with a lower set, or they weren't coded in when installed.

Unless what? Please read post#1 again. Index #1 and index #12 no issues for 35k.

IllSic_Design · 05-01-2018, 11:46 PM

Quote:

Originally Posted by MysticRob

the idea from BMW's own literature about not mixing newer index 11 and above injectors with 10 and older.

Quote:

Originally Posted by feuer

Unless what? Please read post#1 again. Index #1 and index #12 no issues for 35k.

Just going by what BMW says. I get it, no issues, but with injectors I'd rather play it safe and abide by what BMW said in this regard.

feuer · 05-02-2018, 08:30 AM

Quote:

Originally Posted by IllSic_Design

Just going by what BMW says. I get it, no issues, but with injectors I'd rather play it safe and abide by what BMW said in this regard.

Milan · 05-02-2018, 12:39 PM

You can run mixed injectors no problem. Anyone who wants to dispute it can try to give a scientific reason why. Because BMW said so doesn't count.

Phil G · 05-02-2018, 08:13 PM

Quote:

Originally Posted by feuer

lol 35k without issues is self explanatory isn't it? Nothing wrong with running mixed injector indexes. Keep enjoying your 335i

Yeah, I figured it is self-explanatory. However, I just had this fear of thinking it’s OK when in reality damage is occurring at a level that I can’t see or otherwise detect! Glad to see that you and others here seem to think it’s OK.

Quote:

Originally Posted by IllSic_Design

Just going by what BMW says. I get it, no issues, but with injectors I'd rather play it safe and abide by what BMW said in this regard.

Nothing wrong with playing it safe! Especially if the funds are no big deal to you!

dublin14 · 05-02-2018, 08:26 PM

I have mixed as well.some 7s and 12s. No issues at all. But when any of them go I will buy a full set of 12s

05-01-2018, 01:37 PM	#1
Phil G Dominator of Deep South curvy roads 57 Rep 340 Posts Drives: '07 335i Coupe Join Date: Apr 2006 Location: Atlanta, GA iTrader: (0)	Discovered I’ve been running mismatched injectors for 35k miles...... Cylinder #1 stopped firing in my car a few days ago, and checked my injectors as part of the diagnosis. I ultimately found the cause was a dead coil pack, but when I checked the injectors I found that I’m running mismatched injectors! I’ve been running the original index -01 injectors in cylinders #2-6 since I bought the car new 11 years/160k miles ago. However, I found out I am running an index -12 index injector in cylinder #1. An indy shop replaced it 3 years ago at around 125k miles when the injector in cylinder #1 blew. The shop owner (who has been working on BMWs for 35+ years) told me that he found a “close enough version” injector, and calibrated it himself so it would operate in sync with the older injectors. I figured that he found an unused, older version injector, but I apparently misunderstood! The car has been running smoothly for 35k miles since then, and even on a JB4 in Map 5 for 25k miles! Should I consider this the work of a genius, or be concerned? __________________ -'07 335i coupe (build date 02/2007) - Space Grey/Black Dakota/Dark Burl - 6MT/ZPP/ZSP/Nav/CA/Heated Seats. Acquired in Munich 3/2007 via European Delivery. 16 years and almost 220k miles of pure joy! -'06 911 Carrera S - Black/Black - Full Leather/Sport Chrono/Porsche Sport Exhaust/Nav - 80k miles. Acquired 1/2021. One needy old German car just wasn't enough!
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05-01-2018, 08:15 PM	#4
Riceball777 Lieutenant 168 Rep 466 Posts Drives: S2000 618whp/ e90 335i Join Date: Jul 2012 Location: Los Angeles iTrader: (0)	my injectors are also all different index and its been running fine for a long ass time. __________________ 2007 e90 335i pure stage 2 DD turbos, rb inlets
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05-01-2018, 08:29 PM	#5
IllSic_Design Colonel 2111 Rep 2,759 Posts Drives: 12 E92 328i Join Date: Jun 2016 Location: Northern California iTrader: (1)	Yeah I believe I have two 7s with all the rest 9s that I noticed about 20k ago. But my car has no issues so no need to worry unless as stated above you have 11 or higher index mixed with a lower set, or they weren't coded in when installed.
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05-02-2018, 12:39 PM	#11
Milan Captain 203 Rep 665 Posts Drives: F80 M3 Join Date: May 2014 Location: Boise, ID iTrader: (7)	You can run mixed injectors no problem. Anyone who wants to dispute it can try to give a scientific reason why. Because BMW said so doesn't count. __________________ 17 M3 Comp
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05-02-2018, 08:26 PM	#13
dublin14 Banned 159 Rep 388 Posts Drives: Bmw 335i- F150 FX4- Audi A4 Join Date: Apr 2011 Location: Toronto-Canada iTrader: (0)	I have mixed as well.some 7s and 12s. No issues at all. But when any of them go I will buy a full set of 12s
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05-01-2018, 02:52 PM	#2
feuer Major General 4310 Rep 9,230 Posts Drives: wife crazy! Join Date: Apr 2015 Location: Chicago, IL iTrader: (5)	lol 35k without issues is self explanatory isn't it? Nothing wrong with running mixed injector indexes. Keep enjoying your 335i
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