[Dormermike]

Originally Posted by dr_mike

N43B20A, all 4 injectors changed in BMW dealership with revision 11 at 134.000 km, as one got stuck while overtaking. Changed again all 4 at 260.000 km for irregular idling when cold and high fuel consumption. Got the "revision 11" again.
So, they lasted exactly as long as the original ones.

So the index 11 are as failure prone as the earlier ones.

Sad to hear.

Got to wonder just WTF all the revisions were about.

[Dormermike]

Originally Posted by frenchi

There is not such a think as revision 12 on N53....latest is 11. Revison 12 is only for N54

Hi Frenchi you seem knowledgeable about injectors. Do you know if index 11 is still the latest for n53, and also I'm curious what would happen if I used a n54 injector in a n53? They seem to fit...

[frenchi]

Originally Posted by Dormermike

Hi Frenchi you seem knowledgeable about injectors. Do you know if index 11 is still the latest for n53, and also I'm curious what would happen if I used a n54 injector in a n53? They seem to fit...

hi,yes index 11 is the latest and please never ever use an N54 injector on N43 or N53 engine as the flow rates are totally different and you may blow up your cylinder.

[Dormermike]

Originally Posted by frenchi

hi,yes index 11 is the latest and please never ever use an N54 injector on N43 or N53 engine as the flow rates are totally different and you may blow up your cylinder.

OK good to know - thanks!

Are the index 11 better or still failing regularly in your opinion ?

[frenchi]

They still fail every 60-70x miles...premium fuel keeps them alive for a bit longer.

[Dormermike]

Pity to hear the injectors are still POS.

I've just had an oil analysis done showing fuel contamination at 1.2%. That may account for my blue smoke on start (tiny puff) as per phil325i suggestion. These are index 11 injectors replaced July 2016 under mondial warranty. They are technically under BMW warranty parts and labour 2yr and/or mondial.

Question - do I need to wait for them to fail enough to cause misfire or is there a way in ISTA or INPA to check they are sealing properly?

Thanks

[usi227]

In case this helps anyone who stumbles across this thread as I did, looking for a cure to their cold start misfire.

I ordered 3 new genuine index 11 injectors for Ag Auto Parts - they're silly money now but on backlog from BMW so I didn't really have a choice. Replacing bank 1, where I was getting my error codes reduced the misfire to about 30% of what it was but it was still there and bothering me.
I took a punt on 3 used index 11 ones for bank 2 from different sellers and replaced the seals (but used the decouplers they came with), car misfired worse than when I had the 2 index 9s and 1 index 3 that were in there before. Maybe this is because I re-used the decouplers for those 3 but I think at least one of the new (used) injectors were faulty.
I then ordered another 3 genuine new index 11 injectors from Ag auto parts again and decouplers - the cold start misfire is gone (now that I have also done the CCV- See SoupAnxiety's thread on here if you need help with that- google n53 ccv to bring it up).

Long story short, only mess around with used injectors if you have the patience and time to have a punt on them. If you want a guaranteed fix then go for 6 new ones (as expensive as they might be!)

I also changed the oil once fitted as faulty injectors leak fuel into the cylinder overnight and wash the bores of oil leading to higher oil consumption and diluted/contaminated engine oil. In a high revving N/a car it's best to change this as people have attributed unfixed leaky injectors to rod bearing failure so it's best to replace the oil as soon as you can. As a reference, I drove the car about 600-800 miles with the cold start symptoms (EML on cold start that cleared after driving) and when I changed the oil it was still thick and did not smell of fuel at all. It was changed 3,000 miles prior to this.


I will update this thread on the longevity of Index 11 injectors once I've put some proper mileage on them, although I am hoping they will outlast my ownership of the car.

Injectors were replaced at almost exactly 60,000 miles

[Phil325i]

Good advice. For what it's worth I changed to index 11 (all six) at 65,000 miles and so far they've done 57,000 miles without issue.

[usi227]

Originally Posted by Phil325i

Good advice. For what it's worth I changed to index 11 (all six) at 65,000 miles and so far they've done 57,000 miles without issue.

Thanks Phil, that's good to know and a bit of a relief given how light my wallet is at the moment