[535_BiTurbo]

2012 550i

Ive been having an issue with an over fueling condition (P0175) on Bank 2 for about a month and had injector #5 replaced (injector body was leaking fuel externally), then about 2 months later, recently it has begun throwing misfire codes for Cylinder 6 (P0306). Id clear it and then the same code would pop up a few days later. This went on for about a month until it popped another P0306 code and then I pulled the spark plug and it was covered in black soot along with the O2 sensor on bank 2. I replaced both and it was still throwing a P0175 code but no longer a P0306 misfire for about 3 weeks. ( I did all the swapping of the coilpacks and the codes never followed). Then a few days ago car started really acting up while at a redlight an threw a P0300, P0305, P0306 and P0308. I pulled all the plugs on bank 2, cylinder 5 insulator was white (clean) and 6,7,8 were all carbon fouled. I pulled injector 6 and the tip was carbon fouled. I didnt pull injector 7 because I never got any codes for that cylinder and I didnt pull injector 5 because it was replaced 2 months ago. Ive never had any issues with cylinder 8 other than when cylinder 6 injector died. Do you think cylinder 8 injector is still good or should I replace injector #8? Can 1 bad injector cause other cylinders on the same bank to carbon foul?
Fuel System is also showing OL-Fault

[FrannieMoral2017]

Ideally youd want to replace all 8 injectors Plugs and Coils at once if you're doing Injectors. FCP Euro sells them in a 8 pack for $1800 (index 12). At least what I did when I had 1 injector fail. Replaced all 8 along with plugs and coils and haven't had a problem sense.
The OL Fault is most likely an O2 Sensor.

[Sophisticated Redneck]

Originally Posted by FrannieMoral2017

Ideally youd want to replace all 8 injectors Plugs and Coils at once if you're doing Injectors. FCP Euro sells them in a 8 pack for $1800 (index 12). At least what I did when I had 1 injector fail. Replaced all 8 along with plugs and coils and haven't had a problem sense.
The OL Fault is most likely an O2 Sensor.

I will second what the other member said, you want to replace them all at the same time or you will find yourself replacing them one after the other as they all tend to fail around the same time since they all have the same amount of use.

I recommend you also go to FCP and get all new however if you are trying to do it on a budget, I do have a set of 8 Index 12 Injectors I am going to sell for 400 for the complete set of 8. They have approx 65K miles on them. I decided to replace mine with all new along with the HPFP's, Turbos, coils, plugs, etc as I am rebuilding the entire top end, prepping it for a tune + JB4 and wanted no variables. If you are interested PM me.

[535_BiTurbo]

Im not buying used injectors. The dealers doesnt even replace all 8 at one time. Im just going to replace #6 and see how that goes. What’s weird is #7 had a fouled plug but never threw any codes unlike #8. And #5 has a new injector already, but threw a code. Also #6 popped codes while driving and then while at idle, the engine tried to stay running but and thats when 5 and 8 popped misfire codes.

[FrannieMoral2017]

Welp, replace that one and then go ask another group for tips and advice. Any person with any mechanical knowhow understands that when One Injector, Coil, or Plug fails it normally mean theyre all about to because they have the same miles and wear (individually). Those are routine maintenance items and need replaced. I do mine usually around 10k on every other car ive owned (injectors at 50k). Ive just topped 10k in my F07 and did all mine and haven't had a problem with them. Sophisticated Redneck rebuilds his whole damn head because valve stem seals happen to be routine maintenance with these engines.
O2 sensors and MAF could be a cause maybe replace those. OR take it to BMW have them run a Diagnostics on it and don't guess at what it can be.

[Sophisticated Redneck]

Originally Posted by FrannieMoral2017

Welp, replace that one and then go ask another group for tips and advice. Any person with any mechanical knowhow understands that when One Injector, Coil, or Plug fails it normally mean theyre all about to because they have the same miles and wear (individually). Those are routine maintenance items and need replaced. I do mine usually around 10k on every other car ive owned (injectors at 50k). Ive just topped 10k in my F07 and did all mine and haven't had a problem with them. Sophisticated Redneck rebuilds his whole damn head because valve stem seals happen to be routine maintenance with these engines.
O2 sensors and MAF could be a cause maybe replace those. OR take it to BMW have them run a Diagnostics on it and don't guess at what it can be.

Ya I really only intended to do the valve stem seals and not pull the heads, then I decided to to a complete de-carbonization when I saw both the intake and exhaust had massive carbon build up and the exhaust valves were pitted on the borescope so I had to pull the head anyway ...then said what the hell might as well do a mild port & polish while I am in there and polish the pistons and combustion chambers just for the heck of it and practice...30 hours per head later....

[Fynn]

since your having issues on one side, look at your high pressure fuel pump

[mrod88]

Originally Posted by Sophisticated Redneck

I will second what the other member said, you want to replace them all at the same time or you will find yourself replacing them one after the other as they all tend to fail around the same time since they all have the same amount of use.

I recommend you also go to FCP and get all new however if you are trying to do it on a budget, I do have a set of 8 Index 12 Injectors I am going to sell for 400 for the complete set of 8. They have approx 65K miles on them. I decided to replace mine with all new along with the HPFP's, Turbos, coils, plugs, etc as I am rebuilding the entire top end, prepping it for a tune + JB4 and wanted no variables. If you are interested PM me.

I have a a 550i 2011, do you they fit my type?