P0011 and P0016

[MadGus]

2006 Z4MR with 78k miles on the clock. Getting ready to add a Megan Racing catless header and tune from pokeybritches (Severn Tuning).

No dash lights on at all, and before reading my baseline ECU to send off for the tune to be built on, I used INPA to check for any trouble codes. There were two codes P0011 and P0016, and neither were very specific. I will attach the INPA error code detail pic when I get home later today.

I have been chasing a sporadic rough idle (only when fully warmed up) for the past ~4 weeks. Cleaned the MAF sensor, and the car ran totally fine for about a 3k mile road trip. No codes at all thrown at this point.

Since then, these codes have been thrown and cleared twice. No SES light either time. Car will start and idle normally, once up to temp, some spirited driving pulls normally up to 7k rpm’s. At stoplights, idle is still fine, but then after a few more miles, rough idle starts and the two codes get thrown.

If I turn the car off for a few seconds and then restart it, the idle is immediately smooth again (~870 rpm).

About three years ago, I rebuilt the VANOS with a Besian oil pump disk and rebuilt solenoid, fist full of viton o-rings and new hub bolts. I replaced the upper timing chain guide while I was in there.

Adaptations per INPA are within spec. Intake at 1* and exhaust at 4*.

So yesterday I reset the VANOS adaptations after clearing the codes, and took the car for another drive. Same outcome with rough idle only once fully warm P0011 and P0016 codes got thrown without any SES light.

Cleared the codes and now I’m wondering what to look at next:

Remove and clean the solenoid pack and VANOS filter?

Troubleshoot cam and crank position sensors?

Evaluate a worn/stretched timing chain?

I’d like to figure this out before putting the headers and tune on. Appreciate any thoughts folks may have on this!

[MadGus]

Error Screenshots from INPA. Three of the four error codes start with "unknown error location" and the only one with a good description says "camshaft sensor inlet, tooth error" and has code P0016.

And with that, maybe I start by trying to replace the intake camshaft sensor, which looks like I will need to remove the intake manifold, and probably a good idea to clean the ITBs and maybe inspect the DISA valve while I'm in there.

That's not happening for at least a week or two... would love to know if folks think this is the right thing to start chasing!

[MadGus]

Pulled the VANOS off and reset the timing. Took for a test drive and no codes or rough idle at any temperature. Apparently, P0016 is mechanical and not electrical, so I also replaced the intake camshaft position sensor needlessly, but at least it allowed me to clean the ITBs.

Glad she is back on the road and pulling stronger than ever (Severn’s tune is quite noticable improvement!).

[MadGus]

OK... still getting occasional rough idle with a P0344 code now (which is annoying because I didn't get this code until I had changed the intake camshaft position sensor).

P0344 throws and then shortly after, P0011 and P0016 and misfires on cylinders 3, 4, 5 and 6 occasionally accompany the P0011 and P0016.

So, I logged the data on camshaft setpoint and position and engine load on a good run (first chart) and then on one where the symptoms started happening (second chart), both during a single trip.

Choices seem to be:

1) troubleshoot a stuck solenoid valve
2) troubleshoot a wiring/circuit issue
3) troubleshoot a failing intake camshaft position sensor (unlikely as I just replaced this)

Thoughts??

[MadGus]

...and here are the exhaust camshafts from the same two runs (good first, bad second)

When DME finds an error/code, I am reading about how it freezes the VANOS position, but I don't understand why there's movement on the intake cam just before and after the 100 second mark without any movement either way on the exhaust cam.

[Our03z4]

I was chasing random codes for a year, finally found (thanks to the forum) that my MAF connector was bad. The wires become loose from vibration over time causing the computer to freak out from the erratic MAF signals. FCP Euro sells a little kit to replace it, costs like $25. All of my codes are now gone and the car finally idles and runs great again. Not sure if it's the same on the M but on the 3.0si it is.

Hope this helps!

[MadGus]

Thanks, Our03! I did start this journey by troubleshooting and cleaning the MAF sensor, and even got a 3k road trip in without any of the rough idle symptoms returning… alas they are back with codes that don’t point to MAF.

#electricalgremlins!

[Our03z4]

Originally Posted by MadGus

Thanks, Our03! I did start this journey by troubleshooting and cleaning the MAF sensor, and even got a 3k road trip in without any of the rough idle symptoms returning… alas they are back with codes that don’t point to MAF.

#electricalgremlins!

So you replaced the actual MAF sensor wiring connector (harness side not the sensor itself)? Cleaning doesn't solve this. I was getting codes unrelated to the MAF but once this was changed no more issues, this has been over a year ago. Many people have reported the same issues where random codes, unrelated to the MAF, pop up and this fixes it. I would still take care of it, worth the 15mins of work and $25 to be sure rather than chasing more expensive parts. I threw so many parts at mine that I was bummed that it wound up being something so simple. Was even getting ready to buy two new DISAs since it said I needed those as well, nope, still that connector. Think I had six or 7 codes beforehand. Hope you take this advice.

[MadGus]

I have not replaced the MAF sensor harness/wiring, but I have thrown $500 of parts at this problem so far.

Also, I replaced the entire cooling system (radiator, expansion tank, hoses, tstat, water pump) right after the occasional rough idle developed. That line of google searches led me to vacuum leaks and/or a dirty MAF.

I cleaned the MAF and cleaned the electrical connections prior to anything else so far.

P0344 is my current trouble code that is pointing me at those sensors and the VANOS solenoid

But what I think you are saying is “dude… $25 crosses this off of the possibility list.”

I hear you… ordering MAF harness that tomorrow.

[Our03z4]

One other possibility is the new sensor is bad. Did you go with a BMW CPS or an aftermarket brand? These cars don't like anything but BMW when it comes to electrical. Also when was the last time you did a valve cover gasket? Those can be a big air leak on the 3.0si, not sure about the M.

[MadGus]

Ordered the MAF repair kit this morning!

I retimed the cams/VANOS about a month ago (as a part of this troubleshooting) and had the valve cover off to do that… it’s sealed up well and not seeping any oil, so I don’t think it would be leaking any air.

[Our03z4]

Originally Posted by MadGus

Ordered the MAF repair kit this morning!

I retimed the cams/VANOS about a month ago (as a part of this troubleshooting) and had the valve cover off to do that… it’s sealed up well and not seeping any oil, so I don’t think it would be leaking any air.

Okay, cool. Do you have a variable timing motor on the passenger side of the engine? On the 3.0si it has a gasket that can go bad which in turn can cause an air leak, mine leaks oil during hard AutoX. Have you tried smoke testing?

[MadGus]

Hmmm… there’s an exhaust camshaft position sensor on the passenger side of the motor, that has an o-ring which could leak… like the valve cover though, wouldn’t it leak oil and air if it was a problem?

Also, the intake camshaft position sensor I replaced was OEM (BMW logo scratched off) made by VNE (I bought it from FCP or ECS, can't remember which).

[MadGus]

The new, OEM camshaft sensor that I put in was bad. I replaced it with another one, cleared codes and VANOS adaptations and put about 100 miles on her this afternoon.

No rough idle and no codes! Will drive for a few more days before I have full confidence in this being 100% resolved.

Thanks to all who spent time thinking about this with me (including Josh at Severn Tuning and Lama at Beisan)!

[Our03z4]

Originally Posted by Our03z4

One other possibility is the new sensor is bad. Did you go with a BMW CPS or an aftermarket brand? These cars don't like anything but BMW when it comes to electrical. Also when was the last time you did a valve cover gasket? Those can be a big air leak on the 3.0si, not sure about the M.

Hey hey, at least one of the things I threw out was right lol. Glad you got it fixed!

[MadGus]

Well, I’m writing this on the side of the road, waiting for a tow truck. This might have been her last drive. Apparently the codes I had been chasing were not sensors, but skipped tooth from stretched timing chain that finally gave loose today.

Waiting for the tow home now, and will start thinking about options tomorrow (used motor, rebuild or part out being the three I can think of at this point).

[MadGus]

What a day.

[maupineda]

[3002 tii]

Really sorry to hear

[MadGus]

https://perceptionmotorwerks.com/

These folks have three S54 rebuilds in front of me on their schedule. They are local, and mostly build race cars out of german vehicles. I'll post up details of what the cause of my engine's failure was (and what options I will be pursuing).

[GuidoK]

Wow that was some engine fail. I've never seen an s54 fail that way, the chain working it's way out through the valve cover.

Possibly broken chain guides? (one piece of the chain guides is known to fail)
Or all vanos bolts fail on one of the chain wheels (also known weak point).
A broken chain (as the cause) is very rare I think

I hope the head/valvetrain is still ok, but it's an interference engine afaik.... Good luck.

[MadGus]

Yes, it’s an interference engine, so I’m not holding my breath. I replaced the upper chain guide three years ago when I refurb’d the VANOS, so it shouldn’t be that one… we shall see.