[SoupAnxiety]

My N53 is upset with the classic cold start issues and it has a mix of index 07 / 09 injectors. Do the N43 / N53 index 11 injectors still fail? Before I bite the bullet and buy a set of six injectors I'd like to know if the index 11 injectors really do fix the issues in the long run. If the index 11 injectors are reliable my plan would be to source a set of used ones from eBay as 6x £220ish isn't a nice thought!

Thanks!

[Phil325i]

I wish you well with your search for used injectors. Bear in mind that if they claim to have been cleaned/refurbed then they're best avoided. A forum member on here has advised that these piezo injectors can't be re-calibrated and so-called 'refurbished' ones will fail again after a couple of thousand miles,

[Dormermike]

When did latest injectors come out? For a reference point my 03/2012 n53 had a new set of injectors at 43k miles.

I would have expected 03/2012 to be latest, so the new injectors do fail.

[SoupAnxiety]

Thanks for the replies, and for the heads up about refurbishing. I'd like used but "original and working" index 11 injectors.

Index 11 came out in 2014 from what I can gather, this is only based on when people started talking about them online as BMW parts desks can't give me a definitive date. It's possible you have an older version (09 or 10 index around that time).

[frenchi]

index 11 came mid 2013 and they can't me mixed with lower index because the flow rates are different. They can fail mostly if mixed with older revisions on the same bank,other then that much more stable then old ones. If you find a low miles ones even second hand is much better then new ones old index

[SoupAnxiety]

Thanks frenchi, I'll try and source 5x used index 11 injectors. I've already got 1x index 11 in a mixed bank, running this way for 5k miles. I'll get replacements ASAP!

[Dann]

I had a similar problem with my N54.
Ended up just biting the bullet and getting 6 new Index 12 or 13 ones (can't remember what they were)
Luckily I got them from Germany before Brexit (and the pound tanked) so only cost £140 ea including postage

I don't see the point in buying used ones. The history is unknown and could just fail again, at which point you have to buy new anyway and all you've done is spent more money then you needed to.

[Dormermike]

How can I tell what index is installed - is it stamped on the injector?

[SoupAnxiety]

The index number is written on the far right of the 11 digit part number, top right corner of the top of the injector (a grey plastic area).

Logic with used injectors is if I'm buying index 11 which is less prone to failure I've got a "long term reliable" fix. Surely it's a design fault with the early ones, I know that it's a DI system and more complex but I have a 26 year old E30 on its original injectors. I was hoping to buy used index 11, install and forget.

[jamherber]

Always a gamble buying these 2nd hand. You'll need new seals for each one (as they expand and can't be reused) and if the end of the injectors have been remotely 'dinked' whilst being removed, stored or shipped, they'll be scrap as the spray pattern will have been ruined.

Only worth the gamble if you can get them 'very' cheap IMHO.

[SoupAnxiety]

Getting two index 11 with the protective caps on for £40 a pop. I agree it's a gamble, but 5x new price would get me shot my SWMBO.

[Dormermike]

I think the design fault is in the use of piezo crystals tbh.

Though if you consider they fire 4 or 5x under stratified injection as homogenous their MTBF is probably similar. 60k miles is 180-200k miles.. wish there was a way to turn off stratified mode.

[SoupAnxiety]

My N53 is on 155k miles and only one new injector, the other 5x are original. Considering the mileage and that the issue only affects cold starts I can't grumble too much!

[Dann]

You're lucky then. My N54 needed a minimum of two (On different banks) at 55k.
hence why I stuck 6 new ones in it.

[SoupAnxiety]

The N54 has its own injector variety doesn't it? I bought the N53 hoping for simple NA goodness...!

I've got enough index 11 injectors to fix bank 1 and will stay on the lookout for 3x more to go into bank two. Here's hoping it fixes the cold start issue and improves MPG.

[Phil325i]

Originally Posted by Dormermike

I think the design fault is in the use of piezo crystals tbh.

+1 And probably explains why BMW no longer use piezo and have reverted to solenoids.

[Dann]

Originally Posted by SoupAnxiety

The N54 has its own injector variety doesn't it? I bought the N53 hoping for simple NA goodness...!

I've got enough index 11 injectors to fix bank 1 and will stay on the lookout for 3x more to go into bank two. Here's hoping it fixes the cold start issue and improves MPG.

Different part number but same technology.

Mine sorted the cold start but made no difference to fuel economy.

[Dormermike]

My concern longer term would be having to shell out for catalytic converters - the proper ones not the NOX one - because the oh so lean injectors have been overfueling startups and shorten the cat life.

Makes those few extra mpg seem expensive.

[Dormermike]

Originally Posted by Phil325i

+1 And probably explains why BMW no longer use piezo and have reverted to solenoids.

Yup.

[Dormermike]

Originally Posted by SoupAnxiety

Getting two index 11 with the protective caps on for £40 a pop. I agree it's a gamble, but 5x new price would get me shot my SWMBO.

Let us know how you get on. I'm still hoping but sceptical that index 11 is the solution to all our problems (n53)

[SoupAnxiety]

Quick update - I've been able to find two used index 11 injectors. This gave me enough for bank 1 as cylinder 1 was already index 11 (bought new ~5k miles ago). I installed the injectors and recoded the ECU at the start of December. MPG is up slightly (+2 town). Whilst installing I noticed bank 2 had a mix of index 07 and 08 injectors, I moved a spare injector from bank 1 to bank 2 to provide 08 consistency.

I still have the cold start but fault codes are always in bank 2 now, previously I'd get bank 1 and bank 2 codes. To rule out the 08 injector bank move as the cause of the misfire move I've tried reinstalling the original bank 2 injector and other combinations, and prior to the index 11 swap I'd see the same behaviour (one or more injectors on both banks were faulty). I'm playing the eBay waiting game for used index 11 injectors and when I have three more I'll post an update here. Fingers crossed all will be fixed! Thanks for the replies so far.

[Chappers 71]

I'm fairly sure index 11 & above shouldn't be mixed with index 10 & below in the same engine.
Have you tried bmw dismantlers/recyclers there's lots of them out there.

I'm still running original injectors in my 2006 335i @ 100k