2014 X5 50i Running Rich

[sar08011]

Hi all - been a consumer of the great content on this site for many years - but first time being compelled to register and post a story/problem to the boards as this issue just has me (and apparently my dealership) stumped...

I've come across other discussions regarding the N63TU running rich, so seems to be a reasonably common issue, but none of them seem to confirm definitive solutions, so here's where I am:

-At ~ 93k miles, SES light comes on, bank 2 running rich. Soon after that got a drivetrain malfunction when accelerating on the highway. Went ahead and started with the basics - 8 sparks and 8 coils. OE (Bosch) from FCP Euro. Runs smoother and never have another drivetrain malfunction, but, SES is back on within a couple hundred miles. Same bank 2 running rich code.

-Back to FCP Euro - buy and install OE (Bosch) MAFs and and new Genuine BMW engine air filters. Clear the SES codes. Car runs fine, but again, SES back on within a couple hundred miles. Same bank 2 rich.

-Give in and take it to the dealership for diagnosis. They smoke test it and find the bank 2 air intake tube is broken/disconnected, seems to make sense that this could be the culprit (although in hindsight seems like a solution for a lean code, not rich) so I have them replace it for ~$500.

-SES is back on within 500 miles (fortunately enough of a window to pass emissions). Bank 2 rich. Ugh. Annoying that the light is on but runs well for a couple thousand miles. Separately, car is an oil eater - in that time I do an oil/filter change using liqui moly, which helps, but it is still consuming ~ a quart/1k miles, which is what BMW describes as within spec.

-now at ~98k miles, car is noticeably a bit rougher on starts and idles. Its a little shaky as it finds its optimal idle at ~650rpm. Note: I am in CT and this coincides with the transition to winter temperatures.

-take to different BMW dealership for diagnostics, hoping they will point to bad fuel injectors as the culprit, which have the extended warranty. Instead they come back saying bad MAFs and damaged crankcase vent hoses. I tell them that the MAFs are a few months old so that cannot be it. And while the CCV hose may need to be replaced, theres no reason that would be the cause of a RICH code. So, I take the car back and take advantage of FCP Euros lifetime replacement program to put new MAFs in AGAIN. I then replace the CCV hoses (easy with the DIY on this forum). No surprise, neither of these have anything to do with the SES bank 2 issue. Light is back on in 25 miles.

-back to dealership. Very explicitly tell them to inspect the fuel injectors. Sure enough, they confirm that all 8 injectors are bad. Replaced under extended warranty (along with all 8 spark plugs, which were saturated with fuel). They also perform an oil change, noting that the failed injectors can lead to fuel getting mixed into oil (interesting, i didn't realize this...?). They call me to tell me everything is ready ...and then 30 minutes later call back to let me know the SES is back on with bank 2 rich and an airflow too low issue causing drivetrain malfunction. New diagnosis is that the bank 2 high pressure fuel pump failed, so I have them replace it. Fixes the drivetrain malfunction issue, but SES rich bank 2 persists. Dealer suggest they really cant go any further with diagnosis without seeing the car run with Genuine MAFs and CCV hose.

-Given that the N63TU1 class action has now been approved, I requested an oil consumption test. I figure if it fails the test, which I think it may, a whole new engine for 45% off is probably a better investment than 10 more rounds of diagnostics at the dealership. In the meantime, as much as it kills me, I've gone back to FCP Euro for the lifetime warranty on the MAFs, this time paying the premium for Genuine vs OE Bosch. Will report back if that does anything. But in the meantime - any thoughts?

I will also note that the ST/LT trim readings while driving seem responsive to throttle, so doesn't really seem like an 02 sensor issue. My other observation is that cold starts and hot starts (call it <5 minutes, while pumping gas for example) are smooth and peppy, but in between it is very rough. Starting the car after 30 minutes of cool down, it sputters between 300 - 800 rpm for 20 seconds before finding the appropriate idle.

Attaching the notes from the latest dealership trip in case someone notices something/has an idea.

thanks for any input!

[DenBel]

Have the car been ever tuned?

[sar08011]

No tuning.

Been my wife's daily since I picked it up three years ago ~70k miles. It does not get worked very hard. Two cars seats in the back, for perspective

[Chilled]

To confirm thats its not the o2 sensors have you tried to swap them around, bank 2 to bank 1.

Also, what were the actual codes?

[sar08011]

The code is P0175.

I have not done anything to evaluate the O2s other than to confirm they are "working"; by that I mean the ST/LT values are all responsive to changes in throttle loads when driving.

I was actually surprised that O2s never came up in the several rounds of dealership diagnosis, so I figured they had analyzed and crossed it off the list.

Assuming this latest pair of MAFs has no impact, I'll move on to the O2s. When you suggest swapping them, am I right that only the downstreams would relate to a rich code? LONGFT2 is the reading that is often -10% (or worse), which I would think is what trips the SES light?

[Chilled]

Originally Posted by sar08011

The code is P0175.
Assuming this latest pair of MAFs has no impact, I'll move on to the O2s. When you suggest swapping them, am I right that only the downstreams would relate to a rich code? LONGFT2 is the reading that is often -10% (or worse), which I would think is what trips the SES light?

Upstream, you are after the o2 sensor that is pre cat. The downstream sensors are the post cat and are there purely for emission regulations.

[sar08011]

Replaced both MAFs, again. Tried swapping them around - new and old, etc etc.

Finally found a thin wall O2 socket to get at the upstream. Replaced the bank 2 upstream and downsteam sensors (figured might as well do both).

No luck. Same ol' bank 2 running rich fault (stored and pending). STTRM2 is running ~-17% at temperature at idol and LTTRM2 is ~-30%.

[psmith]

Seems like you worked on most of the fuel side. Have you looked at the wastegate duty cycles between banks? I'm thinking a turbo perhaps on the side that is reading rich or a wastegate solenoid on the same side. Also assuming that a compression test has been done and everything looked good in regards to that.

[sar08011]

Thanks psmith - before I go buy a boost solenoid (looks like a bit of a project to get at it in the vehicle) couple questions for you on the possibility of an exhaust side issue…

1) the P0175 fault goes into pending state and/or the CEL is tripped with the vehicle parked and idling. I would have thought that would mean the car was in a vacuum state rather than boost and thus a turbo-related issue shouldnt be the culprit, no?

2) my experience with turbo/wastegate issues on N55 and N20 engines ….they are very quick to trigger BMW specific fault codes, yet I have none. The ODB2 generic P0175 fault is the only fault the car is registering. Could I have a turbo/wastegate issue without throwing a BMW code?

3) when you suggest looking at the duty cycles, is there a module or setting I should be focused on? I have a Foxwell NT510, but am admittedly a novice/only use it for basic analysis and code resetting

[Chrislife]

Possibility of a blocked cat if running rich over a long period - unburnt fuel melts cat?

[psmith]

So just wanted to follow up on this since I had the same bank 2 rich codes with fuel adaptive for that side at .70 to .82 at idle. Under load it would go up to .90 or so. For me, this just started after I did coils and plugs and cleaned mafs. I swapped mafs from side to side with no change. While I was poking around looking for vac leaks one of the attachments from the ccv to the turbo inlets broke right off so I'm guessing it was partially cracked anyway. Replaced both sides and the gaskets to the turbo inlets we're super hard and black. New ones were bright orange and soft. $110 for both sides from the dealer but you probably could find them cheaper if you wanted to wait and order. Upon restart car ran fine but adaptive was still at .82 or so at idle. Disappointed I kept looking but found nothing. Did another key off/on cycle and trims were now .95-.1.2 at idle so it looked like there was a bit of learning involved. Did not reset adaptives with ISTA yet but I don't think I need to.

[sar08011]

Originally Posted by Chrislife

Possibility of a blocked cat if running rich over a long period - unburnt fuel melts cat?

The readings on the ST/LT O2 sensors lead me to believe the cat is functioning (especially now that the O2s have both been replaced and are confirmed reading correctly). Also none of the classic signs - dark smoke, rotten egg smell. Anything else that would indicate a blocked cat? I dont think the cat is the original source of the rich condition, but I definitely worry that it will become an issue with the car now going on six months of running rich.

[sar08011]

psmith - sounds like we've been on similar paths here. When the SES light first came on six months ago, I started with sparks and coils - fixed some performance issues but didn't solve the SES. Dealer identified same issue as your image - cracked/broken turbo inlet on bank 2. Didn't solve the SES issue for me unfortunately. Of course, neither did the subsequent MAFs, injectors, O2s, HPFP.

That said, I may have made a little headway and am curious if anyone has any input here; I did a little research on coils and learned that some people had issues with Boschs that were manufactured in one country vs another. So I went ahead and switched the Bank 2 coils to Delphis (also OE). The SES is ultimately still coming on, but not for the first 100 miles or so. In addition, the fault is now showing up under 07EA module, whereas it had been under 07E8 before. Is there a clue here? I've been unable to find an explanation for the difference between these two modules (both seem to relate to bank 2).

[psmith]

FYI I think at this point you may be at the limits of the foxwell. I definitely saw a change with the turbo inlets moving my fuel adaptions from .78 to .9ish at idle so it was definitely leaking air. With ISTA/D there is also an injector leak down test as well as a balance test you can perform. I'd be interested in the results of those. One quick way to test for an air leak is to get a can of starting fluid and spray at the intake pipes, intercoolers, CCV piping, etc (not at the air filter intake). Any jump in RPM will indicate an air leak. Another thing to try would be to disconnect and temporarily plug the evap line and see if the fuel trims improve. Do your trims trend more towards 1.0 as the rpm increases?

[psmith]

Also this is a silly question but for bank 2 you have been working on the driver's side stuff correct? When I first got this car I would have guessed it would have been the other side.

[sar08011]

Originally Posted by psmith

Also this is a silly question but for bank 2 you have been working on the driver's side stuff correct? When I first got this car I would have guessed it would have been the other side.

ha, yes I am - but I hear you, I double checked myself on this several times as I would have assumed Bank 2 on the passenger side. I actually wasn't fully confident in myself until after the dealer replaced the bank 2 HPFP and from that repair I could confirm that I was, in fact, working on the correct (drivers) side.

[sar08011]

Originally Posted by psmith

FYI I think at this point you may be at the limits of the foxwell. I definitely saw a change with the turbo inlets moving my fuel adaptions from .78 to .9ish at idle so it was definitely leaking air. With ISTA/D there is also an injector leak down test as well as a balance test you can perform. I'd be interested in the results of those. One quick way to test for an air leak is to get a can of starting fluid and spray at the intake pipes, intercoolers, CCV piping, etc (not at the air filter intake). Any jump in RPM will indicate an air leak. Another thing to try would be to disconnect and temporarily plug the evap line and see if the fuel trims improve. Do your trims trend more towards 1.0 as the rpm increases?

thanks, I'll dig on this later this week.

FYI, today I replaced the Bank 2 MAP sensor. Cheap part and five minutes to install, figured worth a shot. Probably not a surprise, but no impact, so can cross that one off the list.

[Chrislife]

Originally Posted by sar08011

The readings on the ST/LT O2 sensors lead me to believe the cat is functioning (especially now that the O2s have both been replaced and are confirmed reading correctly). Also none of the classic signs - dark smoke, rotten egg smell. Anything else that would indicate a blocked cat? I dont think the cat is the original source of the rich condition, but I definitely worry that it will become an issue with the car now going on six months of running rich.

If the cat is blocked (melted) you won't smell anything or see anything, because minimal exhaust gas is making its way out the pipe. Hard to tell on idle but you might notice less fumes coming out one side compared to the other. Symptom would be - unable to build boost on map bank 2.

Another option is the DME for bank 2 has an issue.

Assume compression for all 4 cylinders on bank 2 are good - what was the compression psi?

[DenBel]

Had similar issues. The whole thing started when I tried to pass NY emission inspection with Dinan piggy installed and failed as two monitors were not ready. So switched from stage one to basic via Bluetooth app and still wasn’t able to get those monitors ready. And at some point “ 102006 hot film air mass meter 2, air filter element 2, signal coupling, poor incoming flow” and “ 102004 hot film air mass meter 2, air filter element 2, signal, poor incoming flow” errors were stored in ECUs with unknown status in ista (usually errors in ista existence field are yes no or unknown). So no CEL light, but still was not able to pass the inspection as monitors were ready but those two errors failed the inspection. But if I cleared the errors and drive the vehicle below 3000 rpms the errors would not come up but as son as I floored the car the errors would show up in ista with unknown status, no CEL. So I was driving the car for some time under 3000 rpms, got the monitors ready and passed the inspection. And by the way there was no rough idle or accelerating issues or any other symptoms.
Later on I replaced both mafs, air filters, both charge pipes with gaskets with no luck. Tried resetting engine adaptation values and still the errors were there. Sometimes they come up for bank 1 also. Thought that then dinan piggy could affect the software in ecus, I reflashed they with the same ilevel as it was before and reset engine adaptations again. After initial test drive I got those errors again in unknown state with no CEL, but then they disappeared ( don’t remember if I cleared the errors or by themselves). It was 3 month ago. Was checking the car with ista yesterday and there was no errors. So may be dinan piggy messed something up in ecus settings, but was fixed with flashing. Will keep monitoring.
My errors were with poor incoming flow, the op has running rich errors but looks like there is something in common: more fuel, less air causing those errors. And may be having some piggy tune on a vehicle can cause those errors ( you can’t know for sure about the tune if the vehicle was bought used). That’s just my opinion, but reflashing ecus might help.
Good luck

[sar08011]

Thanks for all the input guys. Learned today that the engine failed both the oil consumption test AND the compression test associated with the Isley settlement. So, failing the compression test …I guess that closes this mystery

[sar08011]

Well, looks like I am reviving this thread much sooner than I’d hoped to. I’m about 250 miles into the full long block replacement as part of Isley. Check engine light is back on, rich bank 2, and engine stutter starts when warm (by that I mean engine has been off for 30 min to an hour).

So, given that effectively every component and hose under the hood is now new, it would seem that DME and/or the bank 2 cat are the only remaining possibilities - as Chrislife and DenBel have alluded.

Any suggestion as to where to start/how to diagnose between the two (Or how to get the dealer to correctly diagnose?) I am now $11k into this - god knows how much has been needless work recommended by BMW (imagine going through 3 sets of MAFs and having the dealer sell you a fourth as part of the engine replacement). The average forum member here seems to have a better clue as to what is going on under the hood of these 50is than the dealers.

[Sophisticated Redneck]

Originally Posted by sar08011

Well, looks like I am reviving this thread much sooner than I’d hoped to. I’m about 250 miles into the full long block replacement as part of Isley. Check engine light is back on, rich bank 2, and engine stutter starts when warm (by that I mean engine has been off for 30 min to an hour).

So, given that effectively every component and hose under the hood is now new, it would seem that DME and/or the bank 2 cat are the only remaining possibilities - as Chrislife and DenBel have alluded.

Any suggestion as to where to start/how to diagnose between the two (Or how to get the dealer to correctly diagnose?) I am now $11k into this - god knows how much has been needless work recommended by BMW (imagine going through 3 sets of MAFs and having the dealer sell you a fourth as part of the engine replacement). The average forum member here seems to have a better clue as to what is going on under the hood of these 50is than the dealers.

Have the MAP sensors on the lower intakes been replaced? (Your truck as 4 of them, 2 on intercoolers, 2 on lower intakes, requires taking our fender lining to get to).

Also, most foxwells can datalog, I would set it up to monitor all 4 O2 sensors under idle, part, and full throttle. Add in MAF and fuel rail pressure data too.