Rough Idle Rough Running...SOLVED

[pestilence]

The problem ended up being a bad DME on bank 1 so after getting a new one to the tune of $2000 all is fine. I did end up replacing all 8 injectors though because I did smell gas in the oil. The problem was still there after injector replacement so the injectors might have been a piece of the issue or possibly a future issue.
************************************************** ***********
Hi All I did some searching and found similar-ish issues with the difference being many folks cars actually ran ok even with rough idle.

After merging onto the highway the car went into limp mode and I was getting misfire codes on multiple cylinders but after clearing multiple times it seemed the issue was cylinder 3. So I replaced all plugs (ngk 97506 gapped to .22) and coils, still misfiring on 3 so I replaced the injector on #3, coded and reset adaptations. No more misfire codes and car is out of limp mode and ran slightly better but still has rough idle and feels like it's dropped a cylinder(misfiring) when driving. I cleaned the MAFS and nothing changed still sounds like a tank and spits and sputters when driving. The other thing is when coming to a stop the idles drop to the point of almost stalling then bounce back. Because of how it runs I haven't driven it more than a mile but I drove it to the gas station and filled up and upon restarting got a 118111 code. I cleared the code and it hasn't returned but I haven't driven it since only idled in driveway. I got ISTA working and I've run a few tests and to be honest I 'm not 100% sure what I'm looking for but from bank 1 to bank 2 there doesn't appear to be anything that's so off it would stand out like O2 voltage or rail pressure (unless both banks values are bad). I was looking for the smooth running test but it appears in my ISTA version (4.10) that is not available.

I pulled the spark plugs and none were wet but I still get an injector feeling so I am about to order new injectors but want to confirm that's the issue before I do and it turns out to be the fuel pump or O2 sensor(s). I also visually checked the pcv valves for cracks and didn't see anything but it was just a visual test.

Any ideas on the issues or what to check or test?


MODS:
BMS Intake
Bootmod3 Stage 1 tune (currently tuned back to stock)

[pestilence]

...update to my own issue. I was digging more with ISTA and came across the injector triggering diagnostic. I triggered all 8 injectors and 7 of them caused the engine to idle rough (rougher than current) then bounce back when turned back on. Injector 3 (the one I replaced) when triggered had no effect on the engine, it kept running the same. So maybe I didn't do the install correctly maybe there was some decoupler debris or something in there. ISTA is reading the correct flow rate so I know I programmed it correctly. I have injectors on order but I'm going to check the wires and then pull 3 out again and see if there is an issue

[Kamate]

Before you pull injector 3 out, just make sure your number 3 coil connector and injector connector are fully seat especially the coil connector. If you have an injector test bulb, you can also plug it in to see if it flashing while idle just to eliminate if you have an open in your injector wiring harness on cylinder 3. I think it’s odd that the new injector is bad. If I recall correct, your engine is using eu5 injector. Hope you will get it fix soon.

[M5Rick]

Pre lci use EU5 injectors, lci use EU6.

[pestilence]

More updates just because I want to help anyone else who might be having issues. I think the issue is injectors but probably more than just #3. I pulled the oil cap off to see if I could smell gas and this is what I see on the cap and smelling into the oil tube it smells like a gas tank. So there is def gas in the oil. I was going to change all 8 injectors any way but this is more evidence of injectors being, at least some part of, the issue.

[crazyinp]

Originally Posted by pestilence

More updates just because I want to help anyone else who might be having issues. I think the issue is injectors but probably more than just #3. I pulled the oil cap off to see if I could smell gas and this is what I see on the cap and smelling into the oil tube it smells like a gas tank. So there is def gas in the oil. I was going to change all 8 injectors any way but this is more evidence of injectors being, at least some part of, the issue.

this is condensation of short trips or not letting the car warm up the oil to normal temp. Fuel in the oil will not show milky as what you see. Those are 2 independent issues.

[pestilence]

Originally Posted by crazyinp

this is condensation of short trips or not letting the car warm up the oil to normal temp. Fuel in the oil will not show milky as what you see. Those are 2 independent issues.

Thanks for the input crazyinp that makes sense there has been a lot of idling and quickly turning the car on and off in the garage the last couple weeks chasing this problem! I was wondering how gas might have gotten that high up.

[crazyinp]

Originally Posted by pestilence

Thanks for the input crazyinp that makes sense there has been a lot of idling and quickly turning the car on and off in the garage the last couple weeks chasing this problem! I was wondering how gas might have gotten that high up.

gas in the oil could be leaking injector, and same short trips. If you have a lot of fuel in your oil I would do oil change ASAP if I was you , as you might actually damage the bearings.

[Kamate]

There is an extended warranty for the injectors and hpfp. Did you contact the dealer to have them do a diagnostic to see what’s going on?

[aleks_m5]

Hello! I had a similar issue on my M5 and turns out that the injectors were the cause of the rough idle. Someone else mentioned there is an extended warranty on the injectors and they are right. You have to take the car to a BMW dealer otherwise they will NOT honor the warranty. It is a 10 year 120,000 mile warranty so you should definitely be covered. It is crucial you have them do the injectors because you could have a double detonation and blow a piston ring and then have to do a rebuild. (Happened to a buddy of mine)

[crazyinp]

Originally Posted by pestilence

...update to my own issue. I was digging more with ISTA and came across the injector triggering diagnostic. I triggered all 8 injectors and 7 of them caused the engine to idle rough (rougher than current) then bounce back when turned back on. Injector 3 (the one I replaced) when triggered had no effect on the engine, it kept running the same. So maybe I didn't do the install correctly maybe there was some decoupler debris or something in there. ISTA is reading the correct flow rate so I know I programmed it correctly. I have injectors on order but I'm going to check the wires and then pull 3 out again and see if there is an issue

Do you remember which function did you use? I was playing today and couldn't find it. Found the rough injector test but that doesn't do much. It show some value that I don't know what it means lol