[Wolf 335]

Originally Posted by Salzamani

Did I replace the coil packs and Spark plugs? Yes and yes. Boy is that a whole other story. I had one Coil pack that had gone bad and was making the car sputter really bad and after replacing them issue was resolved(not related to injector in any way). Purchased them all from FCP. As far as the spark plugs go just heads up this was my experience after replacing them just as general maintenance since they had 60+k miles on them the car actually ran worse much worse and there is a thread that I highly recommend you take the time to read to become familiar with this known issue.

https://www.e90post.com/forums/showthread.php?t=571344

On page 2 iseck1 has a long write up on his findings and on page 3 I share mine.
Once the coil packs and spark plugs are changed and the intakes are cleaned(walnut blasted or clean with CRC) which are all important to do with these engines then you should address any fuel injector issues...

Yeah if you do have a leaky injector just get it replaced as it has a big influence on engine health and fuel economy. The eBay link I left above has been known to be a reliable source. If you do the injector as a DYI be careful how you pull out the old injector, no you don’t have to have the injector removal tool(kinda expensive) in most cases but you also can’t go yanking and prying like crazy either as you risk damaging the head. Research it a bit and you’ll be fine. Also be sure to code the new injectors flow rate. You can use INPA for that, it only takes seconds.

Got any questions feel free to ask there are a lot of good people here that are very knowledgeable and can guide you through your decisions and DYI’s.

I asked you a question (post #38), still waiting for your response.

[Salzamani]

Originally Posted by Wolf 335

Have you inquired about what exactly is rebuilt in this injector?
Can they actually tell you what is the rebuilding process?

Hey buddy sorry I missed that question. My notifications go to my junk mail even though I have redirected them to my inbox repeatedly.

No I have not inquired about the rebuilt process. That is a very good question. Not a bad idea to call them and find out. I bet it is similar to what FCP is doing. And if it’s not that’s ok too. I figured this way, if my 12 year old index 1’s that have 70k miles on them are all doing fine except for 1 of them of course then the odds are good that any index 12 that should have improvements in design should serve me fine for probably many years to come. Also I bet a lot of these injector supplies must be coming form BMW warranty replacement many of which are perfectly fine to start with...

In regards to your other question, my car engine hasn’t blown up either. Lol!

Again I have had 2 of these N54 engines a 2010 535i and now this 2007 335i and have done all the maintenance on them myself. Im 53 years old Have own many cars over the years and have done all my work myself. I’m pretty in-tuned to an engine running right and one that does not. I measure my fuel economy every tank full (my ocd) currently this N54 is running perfect and I will keep monitoring it and will be the first to report if something fails to give everyone a heads up. I’m not shy about admitting it if I’m ever wrong...

For now everything is perfect!

[Bent_remy]

Originally Posted by Salzamani

Hey buddy sorry I missed that question. My notifications go to my junk mail even though I have redirected them to my inbox repeatedly.

No I have not inquired about the rebuilt process. That is a very good question. Not a bad idea to call them and find out. I bet it is similar to what FCP is doing. And if it’s not that’s ok too. I figured this way, if my 12 year old index 1’s that have 70k miles on them are all doing fine except for 1 of them of course then the odds are good that any index 12 that should have improvements in design should serve me fine for probably many years to come. Also I bet a lot of these injector supplies must be coming form BMW warranty replacement many of which are perfectly fine to start with...

In regards to your other question, my car engine hasn’t blown up either. Lol!

Again I have had 2 of these N54 engines a 2010 535i and now this 2007 335i and have done all the maintenance on them myself. Im 53 years old Have own many cars over the years and have done all my work myself. I’m pretty in-tuned to an engine running right and one that does not. I measure my fuel economy every tank full (my ocd) currently this N54 is running perfect and I will keep monitoring it and will be the first to report if something fails to give everyone a heads up. I’m not shy about admitting it if I’m ever wrong...

For now everything is perfect!

What did you use to compress the teflon seal before installing the injector?

[Wolf 335]

Originally Posted by iqraceworks

Nope......running perfect!!!

Just following up to make sure installing one injector STILL didn't blow up your engine?

[iqraceworks]

Originally Posted by Wolf 335

Just following up to make sure installing one injector STILL didn't blow up your engine?

Installed a larger FMIC....bumped up to stage2+ flash.....and the thing is running awesome!! Any day now and I'm expecting it to blow up

At this point.....I think it's safe to say that there are absolutely no issues with mixing in an index 12 injector with other previous index numbered injectors.

[Bent_remy]

Originally Posted by Wolf 335

Just following up to make sure installing one injector STILL didn't blow up your engine?

[Salzamani]

Originally Posted by Bent_remy

What did you use to compress the teflon seal before installing the injector?

It came with a cap on it that kept it compressed. Just remove the cap right before your ready to install it. Obviously don’t remove the cap until you’re ready to install...

[Salzamani]

Originally Posted by iqraceworks

Installed a larger FMIC....bumped up to stage2+ flash.....and the thing is running awesome!! Any day now and I'm expecting it to blow up

At this point.....I think it's safe to say that there are absolutely no issues with mixing in an index 12 injector with other previous index numbered injectors.

+1 here too!

[iqraceworks]

Originally Posted by Salzamani

It came with a cap on it that kept it compressed. Just remove the cap right before your ready to install it. Obviously don’t remove the cap until you’re ready to install...

Yep, when I put in my new injector a few weeks ago...it slit ride in, no issues at all. Just make sure you install it right after you pull the metal cap off of it so that the seal doesn't expand before you get it in.

[Bent_remy]

Originally Posted by Salzamani

It came with a cap on it that kept it compressed. Just remove the cap right before your ready to install it. Obviously don’t remove the cap until you’re ready to install...

Thank you so much.

[Salzamani]

Originally Posted by Bent_remy

Thank you so much.

You’re welcome buddy. Anything else don’t be shy

[RJC612]

Just weighing in real quick cuz i found myself in this exact same predicament. 07 335i 140k trouble free miles on my Index 1 injectors.

Well i just installed new turbos and the car was off the road for about 2 months while i was messing around with everything. When i fired the car back up after everything was done, i had a dead miss on cyl 6. Determined it was an issue with the inkector sticking and a buddy of mine happened to have 1 brand new index 12 laying around he didnt need. He gave it to me for free lol.

Anyways i looked up the index issues and saw everyone saying oh no dont do it and others saying they had mixed injector indexes with no issues. So i just sent it, i stalled the single index 12 and it works great in sync with my 5 other index 1's lol. No issues at all with mixing indexes in my case. I will eventually buy a bunch of used index twelves off a totalled N63 vehicle or something so i have 8 more index 12 injectors to swap out my 5 remaining index 1's i.e. 3 extras in case i ever need them.

[DadsMoneyPit]

Originally Posted by Salzamani

Hello again!

Just to give you an update. I replaced only one leaky cylinder 1 injector over 2 months ago. It’s solved my rough idle issues and improved my fuel economy about 10%. My N54 fires up faster than ever not that it ever had an issue. The spark plug now looks dry and clean. I put in an index 12 and coded it using INPA. All of my other 5 injectors are index1’s. The car pulls normal and you would never know that I have mixed injectors because it runs absolutely perfect. Just do it!

Just want to say Thank You to the OP and others on this thread. Gave me the confidence to purchase a "rebuilt" Index 12 injector from recommended eBay seller and install it in (misfiring) Cyl 5 of my '08 335i with 144k miles (coded it using INPA, another thank you to e90post). Solved my misfire, rough start, and rough idle immediately. I got a walnut blast last July and recently had both low P and high P fuel sensors replaced, as well as downstream O2 sensors on both banks. All that helped, but replacing that leaky injector was final piece of the puzzle.

[Shoooter_j]

Still good with my 5 1’s and 1 12 in Cyl 1 here too 👍

[alpnwss]

A thought: If I have one bad injector in each bank, say 1 and 4. What's worse:
-leaving it until you can afford/decide to stomach the $1388 for a whole set. Annoying.
-replace the 2 bad ones, in which case you'll have mixed but well-performing injectors. Performing they way they should. Whether they perform the exact same, who knows. But they're all new.

I feel like having non-leaking injectors that are mixed is better than same # leaking ones. A leaking injector has wacky/unmatched flow rates too.

Another thing to consider, your oil dilution from running leaky injectors vs non-leaking mismatched ones.

[RJC612]

Originally Posted by alpnwss

A thought: If I have one bad injector in each bank, say 1 and 4. What's worse:
-leaving it until you can afford/decide to stomach the $1388 for a whole set. Annoying.
-replace the 2 bad ones, in which case you'll have mixed but well-performing injectors. Performing they way they should. Whether they perform the exact same, who knows. But they're all new.

I feel like having non-leaking injectors that are mixed is better than same # leaking ones. A leaking injector has wacky/unmatched flow rates too.

Another thing to consider, your oil dilution from running leaky injectors vs non-leaking mismatched ones.

absolutely replace the 2 injectors, even if its just one each bank. I have one index 12 in cyl 6 and the rest of my injectors are index 1 and i have had no misfires or adverse effects. This is with me running about 18 psi on larger aftermarket turbos, not aggressive tune but around the 400whp mark or so while i work out my clutch and fuel system. I dont think its a big issue to do for a while until you can afford all new index 12s which you totally should do eventually.

The real risk with misfires and bad injectors is if they are leaking and ignored/not replaced it can actually deform the hole in the head that the injector is seated into. If that happens, even replacing the injector later properly with new seal and coding can result in constant misfires and leaking at which point your head is no good. Thats what you reallyyyy want to avoid

[tommisch]

Originally Posted by iqraceworks

***UPDATE***

So I finally got around to pulling the bad injector. I think running that Techtron fuel system cleaner helped a little bit...because after sitting all night, the spark plug wasn't wet like it was before (so it wasn't leaking any more)....BUT, the spark plug was really black compared to the others...so for one reason or anther, that injector was running rich.

I pulled the bad index 7 injector, installed the new index 12 injector....coded it in with INPA, and fired up the car. It stumped for a second (I'm assuming because it had to get fuel through the injector), and then settled into a nice idle...no more popping and sputtering like before.

I took the car for a drive..it ran great! I scanned for codes when I got home, nothing.

At this point.....nothing is proving to me that you can't run an index 12 in with other injectors. At some point, I will probably change the other two in that bank out.....but for now, I'm just going to run it!

Hey, I'm having some missfires at idle, I replaced the sparkplugs and coils, when I pulled the plugs cylinder 2 was wet. I want to change the injector for cylinder 2 but before doing that I would love to hear how your car is doing after you changed only one?

[Wolf 335]

Originally Posted by iqraceworks

Installed a larger FMIC....bumped up to stage2+ flash.....and the thing is running awesome!! Any day now and I'm expecting it to blow up

At this point.....I think it's safe to say that there are absolutely no issues with mixing in an index 12 injector with other previous index numbered injectors.

It's been over a year, did your engine blow up from putting in only one index 12 injector?

[Salzamani]

Originally Posted by Wolf 335

It's been over a year, did your engine blow up from putting in only one index 12 injector?

In case you’re curious about my experience too. Had that index 12 rebuilt injector in cylinder 1. All the rest were original index 1’s. I never had an issue with the mixed injectors. The idle was absolutely perfect. Acceleration was perfect. Be sure your plugs and coil packs are also in good shape. I sold the 335i about 4 months ago. Not for any special reason I was simply over it, just wanted a more comfortable car. If it was a manual I would have probably kept it. It always felt like something was missing with an automatic. Like my hand was always on the shifter and I wanted to change the gears... no problem at all to mix the injectors in any way or form. Don’t let anyone tell you different. Just be sure to code it with the correct flow rate just like you would with any injector.

Be sure to read this whole thread. There is a lot of key information.

[SixSix]

I see no need for all the injectors to be matching other than OCD. Speaking from experience, my car has 4 Index12s and 2 Index10s. (previous owner's decisions) I ended up swapping my engine for one with less kms that also burns less oil. Discovered when I went to program the injectors that all 4 of the Index12s weren't coded. After coding them properly the car ran extremely smooth and no longer made a loud raspy noise on cold start and low rpm moderate load.

[iqraceworks]

Originally Posted by Wolf 335

It's been over a year, did your engine blow up from putting in only one index 12 injector?

Nope! Still running strong with an E40 tune pushing around 20psi boost. Running like a top!

[tommisch]

Originally Posted by SixSix

I see no need for all the injectors to be matching other than OCD. Speaking from experience, my car has 4 Index12s and 2 Index10s. (previous owner's decisions) I ended up swapping my engine for one with less kms that also burns less oil. Discovered when I went to program the injectors that all 4 of the Index12s weren't coded. After coding them properly the car ran extremely smooth and no longer made a loud raspy noise on cold start and low rpm moderate load.

Wow my car does all of that 😨 mabye all i need to do is get them coded?