[bmwlover]

Hello. How long do index 12 injectors last? How many miles or hours?
I have a car with n63 engine, produced in 2013/04 and injectors failed at 25000 miles. Engine working hours-1000.

[M-Simon]

For me since 50.000km without no problems so far.

[bmwlover]

You said that you had misfires because of temperature sensor. Can you write a code which sensor do you mean? I think that my dme will show misfires again if I change injectors.

[larshutten]

Depends on driving style, I advice people to drive it like you own it. So floor it when engine is hot. Also quality fuel helps a lot. I have some driving around with 100k km. I also put fuel cleaner in gas tank every service, some claim it helps some claims it will not help. The big enemy is carbon build up in my opinion. Also keep an eye on oil consumption.

[bmwlover]

I change oil in every 3000 miles, 150 hours. Drive it hard. Oil consumption was 0.5 liter in every 3000miles. But when injector started failing used 1liter oil. You have index 12 or older?

[larshutten]

Don’t know index numbers. But what I am saying is that there is no average hours/mileage the injectors last. It depends on a lot of variables.

[bmwlover]

For example m54 engine injectors last morenthqn 200k miles. N63 injectors cannot last so much. But want to know users' practice.

[larshutten]

Well that's very hard to say, it's the same with timing chain how long will it last? No one can tell you exactly, we do know that they are not lifetime which they should be...

Just for compare, N43 also same type of injectors. When user goes with octane 98/102 fuel, drive it hard when engine is hot sometimes. Every service fuel cleaner in tank. They could last a lot longer.

M54 is using old school injection, spray before the valves, this helps cleaning the valves. Direct injected engine don't clean the valves that's an issue for starter, sometimes you could notice that with cold engine low rpm's that car is a little shaky, when engine is getting hot it's gone, this could point out that valves are full of carbon build up. Also spray pattern is very important especially when it does 3 fuel injections at 1 stroke(tripple layer injection?? sorry don't know exact translation). If spray pattern is really off, in case of carbon build up in cilinder/around injector tip, it could also cause misfire's.

But if I remember well you are really focussing on the missfire value in ista? All engine's do misfire even we do not notice it. Firmware detects that till a certain level and will throw fault code. I do think that BMW made that "certain level" a little high for the N63 engine. Because they knew there will be trouble.

Best thing you could do to prevent it is fuel cleaner, high octane fuel, avoid regular short drives and let the rpm rise till max when engine is hot or drive in S mode. When they do fail it is advised to change sprak plugs, wrong spray pattern could causse more heat at certain area in cilinders. Also it's important to ask where the owner get's it fuel from and ask how he is driving the car. High quality fuel will make the car also consuming the car a little less(that's my experience). Also he/she will understand that he must drive it hard, otherwise he/she could better buy a hybrid or 2.0l right?

[bmwlover]

Thank you for the post. I am driving the car and use 98 octane fuel. Have short rides, 30km per start. 100km in a day. Drive car hard but injectors have problem. So will buy new ones,no other solution but do not know which is better: 13538648937 or 13538616079. Read fcpeuro post about it but need to knkw it from people's practice.

[B1257]

Direct injected engine don't clean the valves that's an issue for starter, sometimes you could notice that with cold engine low rpm's that car is a little shaky, when engine is getting hot it's gone, this could point out that valves are full of carbon build up. Also spray pattern is very important especially when it does 3 fuel injections at 1 stroke(tripple layer injection?? sorry don't know exact translation). If spray pattern is really off, in case of carbon build up in cilinder/around injector tip, it could also cause misfire's.

This was the same what I was talking about the first time, carbon deposit. It is very bad on direct injection engines and even more if the spray strategy is in 3 time injection mode. This operation mode is also called low end torque, which means low speed with high torque. It depends even on the driving profile more short distance (also higher exhaust gas recirculation) and longer oil change intervals are more bad and will increase the carbon deposit too.

I also would recommend to use a injector cleaner from time to time and if possible drive the ultimate fuel.
Meanwhile I am driving this fuel on all my ALPINA engines and even on the engines with the former injection system. I can say it is worth the money, even the cumbustion process is better (running smoothness, roughness). Some of our motorsport friends are driving the fuel too with best results.