[Dr777]

Originally Posted by Saif2018

No worries, sort the O2 issues out, then relog, you may not need to do the coils yet.

Have you changed the Coils, the last time they were changed?

I personally haven't changed them but im not sure if they have ever been changed because they are the original Bosch coils. I never had problems with misfires so I thought they would be okay for right now. I planed on buying a new set of eldor coils but not right away if not needed I'll do the o2 sensor and report back. Thanks again

[Grey.Harp]

Hi guys! Really need your help here, fighting errors for some time and don't know where to look further.

I have an MHD Stage 2+ xHP Stage 1, catless downpipes, Wagner FMIC Stage 1, set of new ignition coils, sparks are NGK 1 step with 0.22 gap and they are around 5k miles. Injectors are all 12th revision with around 30k mileage. I have just changed o2 sensors after cats because I had a lot of blue smoke and repeated 2C7B 2C7C codes. It still has smoke and shows these errors. I've managed to log them, here is the log:

https://datazap.me/u/greyharp/e92-33...ata=3-22-25-27

All stabilization off, full-throttle from the start. Error light poped up around 2nd gear. Those pits on throttle look strange to me since I'm pretty sure I was doing full-throttle all the time. And those significant pits in boost just around the gear-change also.

First, it was just o2 errors (2C7B 2C7C), this time it fired more:
29CD misfire cyl. 1
2C2E o2 before cat
2C7B o2 after cat
+ Shadow 2AAF

The thing is - I've made a full engine and turbos rebuild last season less than 15k miles back and everything was just great but now it behaves so strangely.
Last summer I have also changed all vacuum lines, HPFP, charge pipe (COBB), boost solenoids.
I'll be very thankful for your help.

[NoGuru]

Your LPFP cannot keep up so the car is pulling timing. Replace the LPFP and you should be good.

[Saif2018]

Originally Posted by Grey.Harp

Hi guys! Really need your help here, fighting errors for some time and don't know where to look further.

I have an MHD Stage 2+ xHP Stage 1, catless downpipes, Wagner FMIC Stage 1, set of new ignition coils, sparks are NGK 1 step with 0.22 gap and they are around 5k miles. Injectors are all 12th revision with around 30k mileage. I have just changed o2 sensors after cats because I had a lot of blue smoke and repeated 2C7B 2C7C codes. It still has smoke and shows these errors. I've managed to log them, here is the log:

https://datazap.me/u/greyharp/e92-33...ata=3-22-25-27

All stabilization off, full-throttle from the start. Error light poped up around 2nd gear. Those pits on throttle look strange to me since I'm pretty sure I was doing full-throttle all the time. And those significant pits in boost just around the gear-change also.

First, it was just o2 errors (2C7B 2C7C), this time it fired more:
29CD misfire cyl. 1
2C2E o2 before cat
2C7B o2 after cat
+ Shadow 2AAF

The thing is - I've made a full engine and turbos rebuild last season less than 15k miles back and everything was just great but now it behaves so strangely.
Last summer I have also changed all vacuum lines, HPFP, charge pipe (COBB), boost solenoids.
I'll be very thankful for your help.

The throttle dips are fine and expected, they happen when a shift takes place.

Your WGDC is almost Maxing out, but before we jump to conclusions...

As mentioned your LPFP is tanking, sort that out first then relog and go from there. Do one thing at a time and don't throw money and tonne of parts at the problem.

[Grey.Harp]

Thanks a lot guys! Will swap LPFP and share the results. Should I go for some upgrade in that or stock is fine for stage 2+?

[NoGuru]

Originally Posted by Grey.Harp

Thanks a lot guys! Will swap LPFP and share the results. Should I go for some upgrade in that or stock is fine for stage 2+?

If you have the funds and know how, I would upgrade to at least a Walbro 450

[Grey.Harp]

Originally Posted by NoGuru

If you have the funds and know how, I would upgrade to at least a Walbro 450

Ok, will check that, thanks.
Just forgot to mention that it smokes on Idle too. Is that also because of LPFP? I thought lpfp can't do anything wrong on idle

[Dave92N54]

Originally Posted by Grey.Harp

Ok, will check that, thanks.
Just forgot to mention that it smokes on Idle too. Is that also because of LPFP? I thought lpfp can't do anything wrong on idle

Out of the exhaust? When was the last time you had the downpipes off? At idle it's usually turbo seals

[Grey.Harp]

Originally Posted by Dave92N54

Out of the exhaust? When was the last time you had the downpipes off? At idle it's usually turbo seals

Yep, from the exhaust. Downpipes off was in autumn If I'm not mistaken. Should I find oil leaks there if the problem is in seals?

[Dave92N54]

Originally Posted by Grey.Harp

Yep, from the exhaust. Downpipes off was in autumn If I'm not mistaken. Should I find oil leaks there if the problem is in seals?

I believe the easiest method to confirm is to look at the exhaust side with the downpipe off, it would look wet if the seal is bad

[Grey.Harp]

Originally Posted by Dave92N54

I believe the easiest method to confirm is to look at the exhaust side with the downpipe off, it would look wet if the seal is bad

Thanks!

[Dave92N54]

Been trying to track down an intermittent surging at low throttle cruising, so far taking logs of it happening have shown nothing. Only things that look odd in those logs are the AFR and STFT oscillating, everything else looks fine. This includes RPM, it holds steady. It almost looks as if the car is doing it on purpose.

Decided to take a WOT log today. I think I may have found something, and am looking for any confirmation/ideas.

https://datazap.me/u/e92dave/3rd-gea...&data=3-23

If you look at boost vs boost mean, at one point boost flatlines but boost mean doesn't. I feel this would indicate either a leak between the MAP in the charge pipe and the MAP in the manifold/a manifold gasket leak(I say this bc i'm a tiny bit off target), or a bad MAP. The other thing I notice is the initial drop in STFT where it goes negative, and then once boost hits target it starts to go positive and boost is off target, but then when boost starts to hit target again higher up in the RPMs, the STFT tanks. I presume this would be due to something along the lines of an intake leak, which occurs upon hitting boost at a certain point and manages to seal back up as boost drops.

Does my logic seem sound? I cleaned my valves back in December but I will certainly admit that while they were much cleaner, it was no where near as clean as they should be. I'm planning on doing them again in the next few weeks, with a better setup and will be replacing the manifold and TB gaskets, as well as inspecting the manifold for any cracks or leaks so if this seems like the culprit I'll pretty much stop digging.

So i've looked more into what boost vs boost mean actually is and it seems like boost isn't actually being sensed? It's being calculated by the DME based on boost mean and throttle position along with some other factors? I wonder what would cause it to go completely flat for a moment

[Saif2018]

Originally Posted by Dave92N54

Been trying to track down an intermittent surging at low throttle cruising, so far taking logs of it happening have shown nothing. Only things that look odd in those logs are the AFR and STFT oscillating, everything else looks fine. This includes RPM, it holds steady. It almost looks as if the car is doing it on purpose.

Decided to take a WOT log today. I think I may have found something, and am looking for any confirmation/ideas.

https://datazap.me/u/e92dave/3rd-gea...og=0&data=3-23

If you look at boost vs boost mean, at one point boost flatlines but boost mean doesn't. I feel this would indicate either a leak between the MAP in the charge pipe and the MAP in the manifold/a manifold gasket leak(I say this bc i'm a tiny bit off target), or a bad MAP. The other thing I notice is the initial drop in STFT where it goes negative, and then once boost hits target it starts to go positive and boost is off target, but then when boost starts to hit target again higher up in the RPMs, the STFT tanks. I presume this would be due to something along the lines of an intake leak, which occurs upon hitting boost at a certain point and manages to seal back up as boost drops.

Does my logic seem sound? I cleaned my valves back in December but I will certainly admit that while they were much cleaner, it was no where near as clean as they should be. I'm planning on doing them again in the next few weeks, with a better setup and will be replacing the manifold and TB gaskets, as well as inspecting the manifold for any cracks or leaks so if this seems like the culprit I'll pretty much stop digging.

So i've looked more into what boost vs boost mean actually is and it seems like boost isn't actually being sensed? It's being calculated by the DME based on boost mean and throttle position along with some other factors? I wonder what would cause it to go completely flat for a moment

Not sure if this is because of wastegate issues but your off boost target almost 2 PSI till into 4k+

Probably a boost leak or your wastegates need looking into, you have the rattle fix applied?

Have you checked Vanos Int/Ex requested and Actual for both?

Walnut blast could help, if you haven't done it recently.

[Dave92N54]

Originally Posted by Saif2018

Not sure if this is because of wastegate issues but your off boost target almost 2 PSI till into 4k+

Probably a boost leak or your wastegates need looking into, you have the rattle fix applied?

Have you checked Vanos Int/Ex requested and Actual for both?

Walnut blast could help, if you haven't done it recently.

I've definitely considered wastegates, they do rattle. I need to find a stubby enough 10mm so I can adjust the rear. However, I do actually hit target before 4k, it just immediately drops off upon hitting target on initial spool and then seems to recover again around 4k, but my understanding is this isn't necessarily abnormal and 1-2psi is usually not an issue.

I have checked vanos against requested and they seem to be pretty much on par but I can grab a log later if need be, I plan on cleaning the solenoids and MAP today to see if it helps with the surging at all.

No rattle fix here, I tried it for a day or two and even on the lowest setting I kind of hated the lag.

I feel the surging and this supposed leak must be related and due to that I'm not sure it's wastegates, I've logged WGDC in the surging logs and it seems to happen at all kinds of WGDC, not just one. The surging is extremely odd, seems to happen more often once the car is warm, but even then it's very hit or miss and only happens at the slightest throttle, the last log I took shows throttle at 3% and pedal at 6% so very very little input, anymore or completely off the pedal and it stops.

[Bimmer_Bro]

Originally Posted by Dave92N54

I've definitely considered wastegates, they do rattle. I need to find a stubby enough 10mm so I can adjust the rear. However, I do actually hit target before 4k, it just immediately drops off upon hitting target on initial spool and then seems to recover again around 4k, but my understanding is this isn't necessarily abnormal and 1-2psi is usually not an issue.

I have checked vanos against requested and they seem to be pretty much on par but I can grab a log later if need be, I plan on cleaning the solenoids and MAP today to see if it helps with the surging at all.

No rattle fix here, I tried it for a day or two and even on the lowest setting I kind of hated the lag.

I feel the surging and this supposed leak must be related and due to that I'm not sure it's wastegates, I've logged WGDC in the surging logs and it seems to happen at all kinds of WGDC, not just one. The surging is extremely odd, seems to happen more often once the car is warm, but even then it's very hit or miss and only happens at the slightest throttle, the last log I took shows throttle at 3% and pedal at 6% so very very little input, anymore or completely off the pedal and it stops.

Have you ever replaced your boost solenoids?
Which map version of MHD are you running?
Bad boost solenoids can cause inconsistent boosting issues, or not closing the waste gates fully, causing a boost leak. Just a thought.

[studio54]

Originally Posted by Dave92N54

Been trying to track down an intermittent surging at low throttle cruising, so far taking logs of it happening have shown nothing. Only things that look odd in those logs are the AFR and STFT oscillating, everything else looks fine. This includes RPM, it holds steady. It almost looks as if the car is doing it on purpose.

Decided to take a WOT log today. I think I may have found something, and am looking for any confirmation/ideas.

https://datazap.me/u/e92dave/3rd-gea...og=0&data=3-23

If you look at boost vs boost mean, at one point boost flatlines but boost mean doesn't. I feel this would indicate either a leak between the MAP in the charge pipe and the MAP in the manifold/a manifold gasket leak(I say this bc i'm a tiny bit off target), or a bad MAP. The other thing I notice is the initial drop in STFT where it goes negative, and then once boost hits target it starts to go positive and boost is off target, but then when boost starts to hit target again higher up in the RPMs, the STFT tanks. I presume this would be due to something along the lines of an intake leak, which occurs upon hitting boost at a certain point and manages to seal back up as boost drops.

Does my logic seem sound? I cleaned my valves back in December but I will certainly admit that while they were much cleaner, it was no where near as clean as they should be. I'm planning on doing them again in the next few weeks, with a better setup and will be replacing the manifold and TB gaskets, as well as inspecting the manifold for any cracks or leaks so if this seems like the culprit I'll pretty much stop digging.

So i've looked more into what boost vs boost mean actually is and it seems like boost isn't actually being sensed? It's being calculated by the DME based on boost mean and throttle position along with some other factors? I wonder what would cause it to go completely flat for a moment

I wonder too what delta is normal between boost mean and boost ?

It seems inconsistent on mine too. Sometimes it's almost matching, sometimes it has 0.x up to 0.8psi delta.

Is it supposed to have a bit of delta or not ?

From what i remember, the MAP on the intake manifold is capped at a 3 psi or something, and the MAP on the chargepipe (boost mean) at 21.5psi and the "boost psi" value is calculated by DME from the values of both MAP, so i don't how it can be accurate anyway.

If you didn't change your intake and TB gasket when cleaning your valve maybe you can replace them since it's cheap.

There is also an O-ring in the chargepipe.

Another place i think it may leak it's from the small holes that are in the intake ports and that goes to the PCV, if the PCV valve is leaky it probably create a small leak in this area during boost (leak going to the crankcase).

[Dave92N54]

Originally Posted by Bimmer_Bro

Have you ever replaced your boost solenoids?
Which map version of MHD are you running?
Bad boost solenoids can cause inconsistent boosting issues, or not closing the waste gates fully, causing a boost leak. Just a thought.

I have not, they are actually on the way. I've heard a humming from one sporadically so I ordered, hopefully it solves any issues.

I'm running MHD V7.1 1+, I really enjoy it. At first I was on V9 and thought I preferred it after trying V7 for a day but upon trying again I really do like the mid range oomph a lot more.

[Dave92N54]

Originally Posted by studio54

I wonder too what delta is normal between boost mean and boost ?

It seems inconsistent on mine too. Sometimes it's almost matching, sometimes it has 0.x up to 0.8psi delta.

Is it supposed to have a bit of delta or not ?

From what i remember, the MAP on the intake manifold is capped at a 3 psi or something, and the MAP on the chargepipe (boost mean) at 21.5psi and the "boost psi" value is calculated by DME from the values of both MAP, so i don't how it can be accurate anyway.

If you didn't change your intake and TB gasket when cleaning your valve maybe you can replace them since it's cheap.

There is also an O-ring in the chargepipe.

Another place i think it may leak it's from the small holes that are in the intake ports and that goes to the PCV, if the PCV valve is leaky it probably create a small leak in this area during boost (leak going to the crankcase).

All gaskets were replaced, I'm not one to cheap out even if it's not needed. If I remove a gasket, you can bet i'm replacing it even if very new.

You're right about the MAP, I did more reading and it seems to be capped at 3psi or so. Very interesting IMO, seems odd they'd do it this way, seems more prone to "hiding" possible issues if that makes any sense.

Valve cover is a rein unit from BimmerWorld, who I trust very much. PCV is a VTT valve from FCP (installed when I went FBO, so very new) with an RB cap (which I had to modify to fit the VTT valve lol) so I'm doubting issues there. It certainly crossed my mind though, especially due to the surge happening at low throttle/high vacuum and the occasional puff of smoke I get which is incredibly sporadic, may be 3 times in a week, may happen once in a month.

Well, anyway, solenoids are on the way and will be replacing. Discovered my brother has a nice set of stubbies so will be adjusting the rear waste gate once the car cools down.

I did some testing this morning, reset all adaps via INPA. This somehow locked the car in a loop or something, AFR was stuck at 14.68 and no fuel trims, reflashed my map and all was good. Went for a drive, car got pretty hot (it's 90°F today) and didn't do the low throttle surging but however did surge under boost, it definitely seemed more like a wastegate issue so hoping solenoids/adjustment solves it since otherwise the turbos seem to be fine, even with the very intermittent puffs of smoke. I even pulled DPs and checked a few times and exhaust side is dry so they must not be leaking very much, if it is the cause at all. If it ends up being turbos, luckily I have some saved. I'm not totally a power freak (though it would be nice, and I mostly avoid it bc well i'm a college student so avoiding a blown motor is pretty high on my priorities lol) so I'm planning on going with RB OEM billets, seems like a really good option. Cheaper than OEM with the wastegates fixed and a billet wheel sounds pretty good to me.

[Saif2018]

Originally Posted by Dave92N54

I've definitely considered wastegates, they do rattle. I need to find a stubby enough 10mm so I can adjust the rear. However, I do actually hit target before 4k, it just immediately drops off upon hitting target on initial spool and then seems to recover again around 4k, but my understanding is this isn't necessarily abnormal and 1-2psi is usually not an issue.

I have checked vanos against requested and they seem to be pretty much on par but I can grab a log later if need be, I plan on cleaning the solenoids and MAP today to see if it helps with the surging at all.

No rattle fix here, I tried it for a day or two and even on the lowest setting I kind of hated the lag.

I feel the surging and this supposed leak must be related and due to that I'm not sure it's wastegates, I've logged WGDC in the surging logs and it seems to happen at all kinds of WGDC, not just one. The surging is extremely odd, seems to happen more often once the car is warm, but even then it's very hit or miss and only happens at the slightest throttle, the last log I took shows throttle at 3% and pedal at 6% so very very little input, anymore or completely off the pedal and it stops.

Once you've cleaned the solenoids and Tmap, if it still doesn't resolve the issue,

Would suggest you have a dig at the wastegates, if they are not sealing properly to build boost and rattling then I can imagine some boost fluctuations (sealing and unsealing actuators)

Next step, walnut blasting.

[Dave92N54]

Originally Posted by Saif2018

Once you've cleaned the solenoids and Tmap, if it still doesn't resolve the issue,

Would suggest you have a dig at the wastegates checked, if they are not sealing properly to build boost and rattling then I can imagine some boost fluctuations (sealing and unsealing actuators)

Next step, walnut blasting.

Sorry I guess I forgot to mention, they were cleaned when I went for the drive earlier. Car is still cooling down so will get to the wastegate later. I know the front has to be removed to adjust so well, fuck that lol. I'll replace them before I do that in all honesty, just wouldn't be worth it.

I have a summer class coming up that ends in July so if I end up needing turbos, they'll likely get done around that time.

[Dave92N54]

Well, adjusted the rear wastegate. Definitely less surge, my rattle on medium acceleration is basically gone, but I took a WOT log and it was down 2psi pretty much the whole pull, but peak target was also higher. Hoping solenoids will make a change, when I stopped I definitely heard more buzzing from them like i've heard a few times.

Slight update: Car definitely is targeting and hitting higher boost now so, guessing bad solenoids should help as I can't find a leak anywhere along the intake piping.

[studio54]

Originally Posted by Dave92N54

All gaskets were replaced, I'm not one to cheap out even if it's not needed. If I remove a gasket, you can bet i'm replacing it even if very new.

You're right about the MAP, I did more reading and it seems to be capped at 3psi or so. Very interesting IMO, seems odd they'd do it this way, seems more prone to "hiding" possible issues if that makes any sense.

Valve cover is a rein unit from BimmerWorld, who I trust very much. PCV is a VTT valve from FCP (installed when I went FBO, so very new) with an RB cap (which I had to modify to fit the VTT valve lol) so I'm doubting issues there. It certainly crossed my mind though, especially due to the surge happening at low throttle/high vacuum and the occasional puff of smoke I get which is incredibly sporadic, may be 3 times in a week, may happen once in a month.

Well, anyway, solenoids are on the way and will be replacing. Discovered my brother has a nice set of stubbies so will be adjusting the rear waste gate once the car cools down.

I did some testing this morning, reset all adaps via INPA. This somehow locked the car in a loop or something, AFR was stuck at 14.68 and no fuel trims, reflashed my map and all was good. Went for a drive, car got pretty hot (it's 90°F today) and didn't do the low throttle surging but however did surge under boost, it definitely seemed more like a wastegate issue so hoping solenoids/adjustment solves it since otherwise the turbos seem to be fine, even with the very intermittent puffs of smoke. I even pulled DPs and checked a few times and exhaust side is dry so they must not be leaking very much, if it is the cause at all. If it ends up being turbos, luckily I have some saved. I'm not totally a power freak (though it would be nice, and I mostly avoid it bc well i'm a college student so avoiding a blown motor is pretty high on my priorities lol) so I'm planning on going with RB OEM billets, seems like a really good option. Cheaper than OEM with the wastegates fixed and a billet wheel sounds pretty good to me.

Ok, yep i asked for the gasket just by curiosity, some players here cleaned their intake valve without changing them and without problem, but i agree that changing them is not a money concern.

N54 cars are some cars to which we are attached, i guess we love them, i never logged or checked some much parts of a car before my N54