[Cabdriver]

Bank 2 still has original injectors index 6. I will be replacing them with new Index 12s soon as when i get off the throttle they seem to not want shut down fully with any timliness.
2009 e90
78k miles
6mt, fbo
Bank 1 replaced at 74k due a leaky injector

[GnomeChild]

Maybe the real Index 12s were the Index 1s we replaced along the way....

[iqraceworks]

I'm running a mix of index 12, 1, 7, and 4's . Not sure which ones (if any are original).....but the cars runs like a top.

[TheMidnightNarwhal]

I have one Index 12 and rest are original 10s I believe.

[BRG_N54]

My '07 has all original index 1's, my '08 has all index 7's. No misfires or performance issues on either vehicle.

[Salzamani]

Yeah all those technical claims the dealers have made throughout the years about running the same index per bank and index 12’s all a bunch of hoax. Just trying to create more work for their BMW dealer service departments. No one that has ever run any combination of index injectors that I have research has reported any issues. Just have to input the flow rate of each injector of course.

[iqraceworks]

Originally Posted by Salzamani

Yeah all those technical claims the dealers have made throughout the years about running the same index per bank and index 12’s all a bunch of hoax. Just trying to create more work for their BMW dealer service departments. No one that has ever run any combination of index injectors that I have research has reported any issues. Just have to input the flow rate of each injector of course.

Yep...exactly. It's funny how I still see people on the 335i Facebook groups saying the whole "you can't mix index 12 injectors or it will burn something up".....and then hundreds of guys chime in with "yes you can, I've been doing it for years" type comments.......

Still waiting for someone to explain to me why an index 12 injector is going to change it's mixture calibration based off of what index injector is in the cylinder next to it.......

That whole thing was just a way for BMW to sell people entire sets of injectors when one was bad.

[TheMidnightNarwhal]

Originally Posted by iqraceworks

Yep...exactly. It's funny how I still see people on the 335i Facebook groups saying the whole "you can't mix index 12 injectors or it will burn something up".....and then hundreds of guys chime in with "yes you can, I've been doing it for years" type comments.......

Still waiting for someone to explain to me why an index 12 injector is going to change it's mixture calibration based off of what index injector is in the cylinder next to it.......

That whole thing was just a way for BMW to sell people entire sets of injectors when one was bad.

Do we know if it's a dealer thing or did BMW came out with a bulletin? I can't recall. But IIRC the reason given is that since Index 11, they changed the way they are built and calibrated, meaning the calibration value you input is not calibrated on the same basis as the other built differently so they will never be technically perfectly calibrated on the bank. I'm sure in reality there is just a slight difference and BMW engineers thought it was important but in our real world experiences it's just so marginal.

In TIS the worst thing it says if the injectors aren't calibrated is car will run rough or engine won't start so I assume at worst if someone is unlucky that might happen. But yeah we should be good

[Phil G]

218k miles here on 5 of the original Index 1 injectors (02/2007 build)!

The injector in either cylinder 1 or 2 (can't remember) blew up about 10 years ago and my indy replaced with an index 6 or 7 I believe (will have to check). Either way, glad that even that even my "subpar" injector in that cylinder still is alive and kicking.

I'm tempted to have all 6 injectors cleaned, but I'm also nervous about the injectors being screwed up during disassembly.

[iqraceworks]

Originally Posted by Phil G

218k miles here on 5 of the original Index 1 injectors (02/2007 build)!

The injector in either cylinder 1 or 2 (can't remember) blew up about 10 years ago and my indy replaced with an index 6 or 7 I believe (will have to check). Either way, glad that even that even my "subpar" injector in that cylinder still is alive and kicking.

I'm tempted to have all 6 injectors cleaned, but I'm also nervous about the injectors being screwed up during disassembly.

I could be wrong....but I'm pretty sure they don't completely disassemble the injector to clean it. They just run pressurized cleaning solution through it as it's cycling.

[Salzamani]

Originally Posted by Phil G

218k miles here on 5 of the original Index 1 injectors (02/2007 build)!

The injector in either cylinder 1 or 2 (can't remember) blew up about 10 years ago and my indy replaced with an index 6 or 7 I believe (will have to check). Either way, glad that even that even my "subpar" injector in that cylinder still is alive and kicking.

I'm tempted to have all 6 injectors cleaned, but I'm also nervous about the injectors being screwed up during disassembly.

If it ain’t broke don’t fix it.

[TheMidnightNarwhal]

Originally Posted by iqraceworks

I could be wrong....but I'm pretty sure they don't completely disassemble the injector to clean it. They just run pressurized cleaning solution through it as it's cycling.

Yeah the injectors cannot be disassembled. It's what GB remanufacturing wrote me.

[feuer]

Originally Posted by Phil G

218k miles here on 5 of the original Index 1 injectors (02/2007 build)!

The injector in either cylinder 1 or 2 (can't remember) blew up about 10 years ago and my indy replaced with an index 6 or 7 I believe (will have to check). Either way, glad that even that even my "subpar" injector in that cylinder still is alive and kicking.

I'm tempted to have all 6 injectors cleaned, but I'm also nervous about the injectors being screwed up during disassembly.

I might have some good order index 1 for you to make complete set

[Phil G]

Originally Posted by TheMidnightNarwhal

Yeah the injectors cannot be disassembled. It's what GB remanufacturing wrote me.

Got it!

Originally Posted by feuer

I might have some good order index 1 for you to make complete set

Good to know! The non-Index 1 still is going strong after 10 years, so I'm inclined to keep as-is now. If it fails though, I know who to DM!

Now I just need to replace my HPFP that finally failed after 218K miles. Really wish I did years ago when HPFPs were only $300-ish....rather than the $1K they are today.

[1Bad335turbopsi]

2007 original injectors 156,000 miles...basic bolt ons.....

[feuer]

Originally Posted by Phil G

Now I just need to replace my HPFP that finally failed after 218K miles. Really wish I did years ago when HPFPs were only $300-ish....rather than the $1K they are today.

Don’t be. Nobody can tell when something would fail. So it’s also a possibility that the replacement would’ve been short lived. Unless you are upgrading, if not broken leave it alone.