Need help with fuel injectors

wokenick · 01-19-2021, 01:41 PM

I had a misfire with my 07 335i, so i was replacing the spark plugs and when i pulled out the plug farthest back (cylinder 1 i believe) the plug had more carbon on it than the others and had a slight gas smell, figured ok i have a leaking fuel injector.

I could use some help pointing me towards how to figure out which fuel injectors are needing replaced and what to replace them with

All 6 fuel injectors are index 2 (each one ends with 02, and what i’ve read that indicates the index) from what i’ve read it seems people have a mix of index2,9,and 11 so i’m just kinda lost on what i should replace them with, i’ve already read i should upgrade the index i’m just lost on what index i should upgrade to

i’d appreciate any feedback or advice, if you need any other info to help me out i’ll give it and i’ll include pictures

Phil325i · 01-20-2021, 05:20 AM

Pretty sure on the 335i they're up to index 12. Best to source them from a BMW dealer and tell them you want the latest iteration. You should not replace just one. You must replace all in the same bank (cylinders 1-3 or 4-6). TBH if yours are index 02, I would say it's time to replace them all...

Chapperss · 01-20-2021, 06:50 AM

I did the research on replacing single injectors - not a single person I can find who has had an issue replacing just one. That includes mismatching lower indexes with the new 12`s (general advice is not to mix indexes above 10 with the lower ones and replace in banks).

I did this research because I thought I might need to replace an injector but it turned out to be the coil.

Emilime75 · 01-20-2021, 08:12 AM

For years it was believed that you can't mix and match within a bank, and if you had to replace 1 with a newer index, then you had to replace all 3, at the minimum. It's recently, like in the last year or two, been reported that mixing them has no I'll effect. The latter makes sense since the injectors have to be coded to the DME, anyway. Regardless, there's 2 points of view on matters like this. The "it's not broke, don't fix it" crowd, and the "while you're in there, you might as well" types. I'm of the while I'm in there type, so I'd replace them all.

As for what to all to replace with them - start by buying them from a reputable source, not ebay, not amazon, not some random dude on a forum. Reason being is that there are counterfeits out there. Also avoid "refurbished" claims. Buy them new from a place like FCPEuro. Add decoupler rings for how ever many injectors you decide to buy/replace. That's all you need, injectors and decoupler rings. The new injectors will already have new seals on them, and caps that keep them compressed until you're ready to install them - don't remove those caps until the moment you're ready to drop 1 in, i.e. remove 1 old injector, pull the cap from the new injector and install right away. Pay close attention to how the clamping plate is installed, it has a bend to it which is critical. You want the high side of the bend to face up, so when the bolt is tightened down the plate acts as a spring which holds the injector in place and allows some shock absorption every time that cylinder fires.

Phil325i · 01-20-2021, 01:41 PM

This is the advice I was referring to (feel free to ignore it of course):

Injector advice.pdf

Emilime75 · 01-20-2021, 08:18 PM

...which is dated 2013.

Steve Sas · 01-24-2021, 08:22 AM

Check and see if you are entitled to injector upgrades from that BMW recall.
I remember they extended it. Worth a try.

01-19-2021, 01:41 PM	#1
wokenick Registered 0 Rep 1 Posts Drives: 2007 bmw 335i Join Date: Jan 2021 Location: north carolina iTrader: (0)	Need help with fuel injectors I had a misfire with my 07 335i, so i was replacing the spark plugs and when i pulled out the plug farthest back (cylinder 1 i believe) the plug had more carbon on it than the others and had a slight gas smell, figured ok i have a leaking fuel injector. I could use some help pointing me towards how to figure out which fuel injectors are needing replaced and what to replace them with All 6 fuel injectors are index 2 (each one ends with 02, and what i’ve read that indicates the index) from what i’ve read it seems people have a mix of index2,9,and 11 so i’m just kinda lost on what i should replace them with, i’ve already read i should upgrade the index i’m just lost on what index i should upgrade to i’d appreciate any feedback or advice, if you need any other info to help me out i’ll give it and i’ll include pictures Attached Images
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01-20-2021, 05:20 AM	#2
Phil325i Brigadier General 645 Rep 3,227 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	Pretty sure on the 335i they're up to index 12. Best to source them from a BMW dealer and tell them you want the latest iteration. You should not replace just one. You must replace all in the same bank (cylinders 1-3 or 4-6). TBH if yours are index 02, I would say it's time to replace them all... __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
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01-20-2021, 06:50 AM	#3
Chapperss I only ride park 517 Rep 385 Posts Drives: e93 335i Msport FBO 2+ Join Date: Aug 2020 Location: Portsmouth iTrader: (0)	I did the research on replacing single injectors - not a single person I can find who has had an issue replacing just one. That includes mismatching lower indexes with the new 12`s (general advice is not to mix indexes above 10 with the lower ones and replace in banks). I did this research because I thought I might need to replace an injector but it turned out to be the coil.
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01-20-2021, 08:12 AM	#4
Emilime75 Colonel 1225 Rep 2,476 Posts Drives: 2010 335i E92 LeMans Blue Join Date: Dec 2017 Location: Merica! iTrader: (1)	For years it was believed that you can't mix and match within a bank, and if you had to replace 1 with a newer index, then you had to replace all 3, at the minimum. It's recently, like in the last year or two, been reported that mixing them has no I'll effect. The latter makes sense since the injectors have to be coded to the DME, anyway. Regardless, there's 2 points of view on matters like this. The "it's not broke, don't fix it" crowd, and the "while you're in there, you might as well" types. I'm of the while I'm in there type, so I'd replace them all. As for what to all to replace with them - start by buying them from a reputable source, not ebay, not amazon, not some random dude on a forum. Reason being is that there are counterfeits out there. Also avoid "refurbished" claims. Buy them new from a place like FCPEuro. Add decoupler rings for how ever many injectors you decide to buy/replace. That's all you need, injectors and decoupler rings. The new injectors will already have new seals on them, and caps that keep them compressed until you're ready to install them - don't remove those caps until the moment you're ready to drop 1 in, i.e. remove 1 old injector, pull the cap from the new injector and install right away. Pay close attention to how the clamping plate is installed, it has a bend to it which is critical. You want the high side of the bend to face up, so when the bolt is tightened down the plate acts as a spring which holds the injector in place and allows some shock absorption every time that cylinder fires.
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01-20-2021, 01:41 PM	#5
Phil325i Brigadier General 645 Rep 3,227 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	This is the advice I was referring to (feel free to ignore it of course): Injector advice.pdf __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
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01-20-2021, 08:18 PM	#6
Emilime75 Colonel 1225 Rep 2,476 Posts Drives: 2010 335i E92 LeMans Blue Join Date: Dec 2017 Location: Merica! iTrader: (1)	...which is dated 2013.
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01-24-2021, 08:22 AM	#7
Steve Sas Private First Class 24 Rep 144 Posts Drives: BMW 335i 2008 Join Date: May 2020 Location: Sydney iTrader: (0)	Check and see if you are entitled to injector upgrades from that BMW recall. I remember they extended it. Worth a try.
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