[titandavid2008]

I have been getting misfire codes from cylinder 1, I did the whole switching the coils around to other cylinder to see if the misfire would follow, sometimes it does, sometimes it doesn't. Decided to go ahead and replace the coils and the spark plugs as I do not know when it had been done last if at all. I got the NGK's and the BAV Auto coils from ECS Tuning. Now it is throwing a P0312E and P0174. The reason I mention no P0171 is because that is what I keep getting asked when I mention P0174. I have called a few shops around me and they are just trying get me in the shop. I'm not driving it anywhere; so nobody is of any help.
For troubleshooting I have swapped the new coils out for the old ones; it runs just as rough, and I did reset the codes, they just came right back on. Went ahead and pulled the new spark plugs and verified the gaps on all 6. One thing to note though: ever since I changed out the coils and spark plugs, the engine has been running for less then 10 mins total time. When I pulled cylinder 1 the new spark plug was nasty looking, not wet at all, but dark brown and almost black. The other 5 are looking brand new. Thats as much as I can think of right now. I did a smoke test (hopefully I did it right) to see if maybe I messed something up, but that seemed to be fine. I'm looking for any and all ways I can troubleshoot this issue more. One thing I might do is call BMW and see what they think could be the problem. I'm really lost here.

[arkie6]

P0312E code? That is a new one on me. It is not listed in the Bentley manual and a google search shows P0312 = Cylinder 12 misfire.

I resolved my intermittent P0171 and P0174 codes by replacing my fuel injectors with new index 12 injectors.

[gbalthrop]

Originally Posted by titandavid2008

I have been getting misfire codes from cylinder 1...Decided to go ahead and replace the coils and the spark plugs ...Now it is throwing a P0312E [NO such code, presume you mean P312E?] and P0174...When I pulled cylinder 1 the new spark plug was nasty looking, not wet at all, but dark brown and almost black. The other 5 are looking brand new.

QUESTIONS:
1) Are you SURE the black plug is #1 (FRONT) and NOT #6 (REAR)?
2) When you were getting "misfire" codes BEFORE changing plugs/coils, WHAT code(s) were you reading?
3) WHAT Scan Tool or Software are/were you using to read codes?
4) Does that Tool provide DEFINITIONS of the Fault Codes, and/or Freeze Frame Data?

Here are the Definitions of those two codes, Bentley 1st & BMW Fault Code Lookup 2nd:
P312E | 2E35 | Cylinder 6 High Pressure Injector Low Side / High Side Electrical
P312E | 2E35 | DME: Fuel injector, cylinder 6, activation | MSD80

P0174 | 29E1 | System Too Lean (Bank 2)
P0174 | 29E1 | DME: Mixture control 2 | MSD80

My interpretation of those definitions is that the Bank 2 (Cylinders 4,5,6) Pre-Cat O2 Sensor is detecting too much O2 (Too LEAN). That condition is due to malfunction of the #6 Injector due to an Electrical Fault, such as a loose Connector or wiring damage.

If the #6 Injector is NOT activating/ pulsing, then NO fuel is being injected into that cylinder. The Fault could be constant, or intermittent. I can't explain WHY there is NO P0306 for "Misfire" on cylinder 6, as if NO fuel is being injected, then NO power is being provided by that cylinder, and there SHOULD be a P0306 Fault Code, since the "misfire" fault is actually the result of reduced power in a cylinder, as compared to cylinder before/after that cylinder in the firing order.

So let us know what Scan Tool/Software you have (INPA/ISTA is a plus) and we can suggest further tests. Check the #6 Injector (Y6106) Connector & wiring per this TIS circuit diagram, and Connector X6106 "Installation Location" (as viewed over Right Fender/ Wing):
https://www.newtis.info/tisv2/a/en/e...ection/dAB3Dk4
https://www.newtis.info/tisv2/a/en/e...nder-6/SDv1Pbp

The White wire at Pin #1 of Connector X6106 should have 12V+ when Ignition ON (Terminal 15 Active) and the Brown wire at Pin #2 is the Ground Pulse from the DME which activates/ pulses the Injector.

George

[titandavid2008]

Originally Posted by gbalthrop

QUESTIONS:
1) Are you SURE the black plug is #1 (FRONT) and NOT #6 (REAR)?
2) When you were getting "misfire" codes BEFORE changing plugs/coils, WHAT code(s) were you reading?
3) WHAT Scan Tool or Software are/were you using to read codes?
4) Does that Tool provide DEFINITIONS of the Fault Codes, and/or Freeze Frame Data?

Here are the Definitions of those two codes, Bentley 1st & BMW Fault Code Lookup 2nd:
P312E | 2E35 | Cylinder 6 High Pressure Injector Low Side / High Side Electrical
P312E | 2E35 | DME: Fuel injector, cylinder 6, activation | MSD80

P0174 | 29E1 | System Too Lean (Bank 2)
P0174 | 29E1 | DME: Mixture control 2 | MSD80

My interpretation of those definitions is that the Bank 2 (Cylinders 4,5,6) Pre-Cat O2 Sensor is detecting too much O2 (Too LEAN). That condition is due to malfunction of the #6 Injector due to an Electrical Fault, such as a loose Connector or wiring damage.

If the #6 Injector is NOT activating/ pulsing, then NO fuel is being injected into that cylinder. The Fault could be constant, or intermittent. I can't explain WHY there is NO P0306 for "Misfire" on cylinder 6, as if NO fuel is being injected, then NO power is being provided by that cylinder, and there SHOULD be a P0306 Fault Code, since the "misfire" fault is actually the result of reduced power in a cylinder, as compared to cylinder before/after that cylinder in the firing order.

So let us know what Scan Tool/Software you have (INPA/ISTA is a plus) and we can suggest further tests. Check the #6 Injector (Y6106) Connector & wiring per this TIS circuit diagram, and Connector X6106 "Installation Location" (as viewed over Right Fender/ Wing):
https://www.newtis.info/tisv2/a/en/e...ection/dAB3Dk4
https://www.newtis.info/tisv2/a/en/e...nder-6/SDv1Pbp

The White wire at Pin #1 of Connector X6106 should have 12V+ when Ignition ON (Terminal 15 Active) and the Brown wire at Pin #2 is the Ground Pulse from the DME which activates/ pulses the Injector.

George

1. I am sure that it is cylinder 1 as it was nearest the radiator.
2. I was getting misfire codes before the changing of coils and spark plugs. It was always cylinder number 1. Now I do not get those misfire codes.
3. I'm using a cheap scan tool from Walmart. An Autolink Autel part number AL319. I know its not the best thing I could be using, but it is what was readily available at the time.
4. When my scan tool first brought up what turned out to be the P312E, it asked me to identify the make of car first.

I'm attaching 1 picture of what the scan tool is reading. This is a new code as of today.....literally 5 minutes after reading your response. This is a new code. My second pic, that wont upload, is the P0174.

Because of what you posted and now this new code, I will check my cylinder 6 connections and let you know the results.

[titandavid2008]

***UPDATE***
So I went ahead and played around with the cylinder 6 wiring. Made sure it was seated and that nothing was broken or what-not. Started it up
and the engine smoothed out after a few seconds. I went ahead and cleared the codes and did another scan, even drove it around, no new codes came up.
However, the engine is making a weird sound while at idle and driving. The best way i can describe the way it feels, is like having someone tap the brakes while driving,
just enough to be irritating. I have felt misfires before, this seems different, like its not coming from the same place a misfire would be, it seems more
like an exhaust thing.

[titandavid2008]

I uploaded the video to youtube. The sound starts at 18 seconds in and happens every so often. Here is the URL

[nicsteez]

Originally Posted by titandavid2008

***UPDATE***
So I went ahead and played around with the cylinder 6 wiring. Made sure it was seated and that nothing was broken or what-not. Started it up
and the engine smoothed out after a few seconds. I went ahead and cleared the codes and did another scan, even drove it around, no new codes came up.
However, the engine is making a weird sound while at idle and driving. The best way i can describe the way it feels, is like having someone tap the brakes while driving,
just enough to be irritating. I have felt misfires before, this seems different, like its not coming from the same place a misfire would be, it seems more
like an exhaust thing.

Possibly injector

[gbalthrop]

Originally Posted by titandavid2008

1. I am sure that it is cylinder 1 as it was nearest the radiator. [No codes related to cylinder #1 or Bank #1 (Cyl. 1,2,3) so wonder if there was oil in the plug tube (VCG leak), and electrode got "dipped" when you remove plug? Can't think of anything else, unless you were getting TOO RICH code on Bank #1, P0172]...
3. I'm using a cheap scan tool from Walmart. An Autolink Autel part number AL319. I know its not the best thing I could be using, but it is what was readily available at the time. [That's a perfect Entry-Level Scan Tool. I got one from Amazon when they had a "Flash Sale" for $24 (normally $35). It will NOT read Coolant Pump codes 2E81 - 2E85 as there are NO P-code equivalents, but it WILL read most everything else in the DME. The three codes you read (P312E, P0174 & P0206) were all you needed to diagnose a fault in the #6 injector wiring. I have INPA and it can read fault codes and Parameters in ALL ~ 20 Modules, but the Autel 319 is a good basic tool for cars of ALL makes, so don't let people tell you that you need to spend a TON of $$ on something else, just to diagnose ENGINE faults. It WILL read Freeze Frame Data, so next time BEFORE you clear the code, snap a photo of the FF Data as well as the code number & Definition. See pages 31-32 of the Manual. If Walmart didn't provide a pdf manual (47-page), you can download it from Amazon or Autel.]
4. When my scan tool first brought up what turned out to be the P312E, it asked me to identify the make of car first.

P-codes that have a "1" or "3" in the first space after the "P" (as opposed to a "0" or "2") are "Manufacturer-specific" codes, so that's why it asks for a "P3xxx" code but NOT for P0206 or P0174.

Hope you got it sorted. I would be more confident if you had clearly identified a loose or damaged wire, corroded connector, etc., but at least all three codes point to #6 injector circuit, in case there are intermittent or recurring faults.

I could NOT identify anything from listening to the audio you posted. If any new codes or symptoms, post back.

George

[Maestro]

that sound is valve tick, you need to run the car around a bit and do some heavy acceleration to make it go away. Since you were getting the code the car most likely had turned down the power so not to damage anything so it was not pumping oil into valve train as much as it should have.

https://www.quirkyuncle.com/2013/04/...w-lifter-tick/

https://www.e90post.com/forums/showt...ght=valve+tick