[Tort74]

Recently purchased and slowly working through all of the little gremlins. My question is about the injectors, can they be mixed? Vehicle came with index 8, by barely noticeable misfire at highway speeds, and the black soot coming from the tailpipe and misfire on 5 code that I got all that leads me believe one of the injectors is bad.
I have 2 index 12 currently on the way, can they be installed along with the existing index 8 replacing just the bad ones or do these things have different flow rates and have to be replaced as a set?

[E93Dude]

There has been endless chatter on this forum about this, but I am of the opinion that you can include whichever injector series together you want, but YOU MUST code them into the DME using Protools, INPA, ISTA or some other OBD II scanner (Autel, XTool, SnapOn, etc..). I have 5 series Ones’s and 1 series nine, and zero problems.

Just out of curiousity, where did you irder your index twelves?….

[Frozz]

Typically, you want to keep each bank either indexes 1-10 or 11 and 12 if you plan to mix.

Example:

bank 1(cyl 1-3): 8 8 10
bank 2(cyl 4-6): 12 11 12

only 1-10 are mixable with each other
only 11 and 12 are mixable with each other

You will need to code any injectors you plan to replace via INPA. Also, seals must be changed whenever an injector comes out of the head otherwise you run the risk of ovaling out the injector bores(especially if you forget to install decouplers). Fresh seals must also always be compressed before reinstalling. From a long-time N54 owner, save yourself the headache if you have the $$ and spend the $2xxx on FCP for lifetime VDO injectors.

[Tort74]

E93Dude
I ordered cheap ones from EBay, for $100 a piece I figured I’ll take a chance. I have access to Autel and found the info on FTC euro on how to program which does not appear too difficult but I’m sure I’ll have more questions on that subject once I actually get into it since nothing ever goes as intended, case and point I can’t manage to wake up a Bosh TPMs sensor with that Autel I had a tire shop install and ofcourse they cannot program Bosh for some strange reason.

[Tort74]

Frozz
Thank you for the good info, I plan on replacing 5, possibly 6 since my standard oil leak is coming from the back of the valve cover. 5 did come back with lean condition so I’m thinking that’s my issue. I still need to get a puller, seals and decouplers, speaking of puller are those injectors a major pain to remove?

[sparkyte]

These chinese ones from ebay are crap, you'll be better off buying index 12s second hand but good luck and keep us informed.

[Tort74]

sparkyte
Yes these are second hand, I wouldn’t put aftermarket injectors in this car. Supposedly came out of a good running veh, we’ll see I guess, but as I mentioned for the price I’m willing to take a chance.

[Tort74]

Frozz
You mentioned something about fresh seals needing to be compressed, what does that entail? I don’t believe I read anything about that or just skipped over that info somehow.

[sparkyte]

Always change the teflon seals and use the n54 injector sealer tool when putting them in.

[Frozz]

Puller/seal tool

https://www.youtube.com/watch?v=6CJYuQJE4xA

[Tort74]

Thank you all for the great advice, I’m sure I’ll have more questions

[TheMidnightNarwhal]

BMW officially says you can only have them matching within a bank but I said fuck that and I only replaced one on my car. My car has all Index 9 and I have one index 12 and there doesn't seem to be issues. It's been three years since and about 50 000KM.

[eastsidaz]

Originally Posted by TheMidnightNarwhal

BMW officially says you can only have them matching within a bank but I said fuck that and I only replaced one on my car. My car has all Index 9 and I have one index 12 and there doesn't seem to be issues. It's been three years since and about 50 000KM.

Yeah, it's a load of crap! Anything to sell more overpriced injectors.

[Tort74]

I feel a little better about replacing 5 and 6 only. Frozz thanks again for the video, looks like a straight forward process, correct tools are the key, wife should be super happy about me spending more money on tools lol

[whyzee125]

The proper way is to match them per bank, index 1-10 can be mixed, but 11 and 12 should be together. Lots of people ignore this rule and it works fine. Absolutely do not get any "reman" or Chinese injectors. New from BMW/FCP, etc. or used from a known good working set that's genuine.

[lowrydr310]

Originally Posted by whyzee125

The proper way is to match them per bank, index 1-10 can be mixed, but 11 and 12 should be together. Lots of people ignore this rule and it works fine. Absolutely do not get any "reman" or Chinese injectors. New from BMW/FCP, etc. or used from a known good working set that's genuine.

99% of the ebay injectors are fake. If you look closely they grind off the # and repaint it. Another dead giveaway is when you see a listing for a set of six and they all have the same calibration numbers. Or if you see a single injector and it has the same calibration number as other ebay listings.

As for mixing injectors, my E93 came with original index 1s on bank 1 and index 9s on bank 3. I got two used index 12s from a trusted source (he got 8 from a S63 and used 6 of the 8 for himself) and replaced two of my index 09s on cylinders 5 and 6 because they were noisy when cold. So bank two has two used 12s and one 9, exactly what BMW doesn't recommend. No major issues except for an occasional misfire on cylinder 5 and some fuel trim discrepancies between bank 1 and 2. Just got 4 brand new index 12s so I'm going to replace that back bank and send off the used 12s for flow testing to see if I can keep them or if I need to buy two more new ones.