05 330i ZHP very rough idle, SES, expert help requested before I go to the dealership

[Aesora]

The car is a 2005 330i ZHP so it’s the M54b30, build date 08/2004 according to www.realoem.com

When I bought the car, it felt a bit sluggish and lacked some power. There was also a fair amount of milky residue in the vent hose off the front right of the valve cover, and the car was absolutely drinking oil.

Performed VANOS seal replacement with Besian seals
Replaced CCV and associated hoses with cold weather kit and the new design oil dipstick tube

Ran great, torque was up as the seals were breaking in. Ran seemingly flawlessly for (I’m guessing) 40 miles or so. Then, when I came to a stop at a stoplight, a rough idle started, and the SES light came on. The car never stalled, but the RPM variances when idling were fairly drastic. I can take a video, but I’m guessing 2-300 RPM variance from the bottom of the bog to the top of the surge, with the bottom being at or below 500 RPMs at times.

I pulled the codes with BMWLogger and a K+DCAN cable onto a spare laptop I have and got the following:
Code--Type---Definition
3C1E--8------Unknown
283F--4------Oil-pressure switch: signal implausible
2974--4------Oxygen sensor before cat. Conv., bank 2: lines
28BC--1------Exhaust camshaft: stiff
28B8--1------Exhaust camshaft: mechanical

At this point it’s probably worth noting that my brother owned the car for 4 years before me and has had a very intermittent SES for O2 sensor related codes for a while, but they always seem to take several months to a year or more to come back on after being cleared.

I cleared all codes with BMWLogger and cleared long term adaptations. The rough idle and SES came back within a few minutes. The 28B8 code is the one that came back instantly, and 28BC cameback on not long after that. Along with the oil pressure switch at some point as well. The car is no longer drinking any oil, it is holding steady right at the full mark on the dipstick. This is when I start throwing parts at it.

Parts I’ve replaced other than VANOS seals and CCV and associated hoses:
MAF cleaned out, replaced, cleaned out new one again.
Upper and Lower intake boots replaced
It has had injector cleaner run through it
Fuel pump and fuel filter were both replaced ~ 2k miles ago
Both intake and exhaust VANOS solenoid pistons
Exhaust VANOS solenoid
Exhaust Cam position sensor (supposedly it is an OEM part from oembimmerparts.com)

I just replaced the cam position sensor last night after the solenoid and pistons didn’t resolve the issue. But the issue persisted after that too, having only run smoothly for a minute or two before the rough idle came back. The codes that were back were 28B8 and 283F before I cleared them, and 28B8 AFTER I cleared them and ran the car for a few minutes. I’ve read every single forum post I’ve seen on any issue even possibly related to this, and I’ve come up with nothing. It doesn’t seem to care if the engine is warm or cold, or if the A/C is on w/ snowflake button lit up and set on 65 or if the heat is cranked up at 80.

I haven’t had the codes read anywhere other than on my own laptop, and I don’t have INPA/EDIABAS/NCSExpert/DIS/GT1 set up correctly, but from my searching it seems like my current code correlates to P0014. I can get this read somewhere to double check if that would prove beneficial, though.

I may be leaving out some information, or other steps I’ve tried, but I’m so tired of thinking about it for now. I’ve been reading forum post after forum post trying to get any new ideas. Any help at all, recommendations or otherwise, would be very much appreciated. Thank you all for your time. (I'm going to cross-post this to a few forums)

[Oli77]

Mother of pearl! Sounds like you have done a lot already.

i may not be of much help, but I did not read anything in your post about cleaning/ inspecting the ICV or the intake boots. Maybe you should look there for the source of our rough idle.

[slater]

as oli said, i would inspect the intake boots, especially the lower one.

re: the oil pressure code - given the work that was just done (CCV), is it possible that you either forgot to plug that back in, or the plug isn't seated correctly?

re: the exhaust cam codes, i would check the VANOS sensor connectors there as well, especially since you just had them apart. i guess it's possible you might have a wiring harness issue as all of those connectors route through the same area - perhaps you nicked something or pinched something upon re-assembly?

peter

[Vas]

I would retrace your steps, make sure everything is connected. Also check for vacuum leaks after the maf sensor because those would be unmetered

[Aesora]

Yeah a vacuum leak has pretty well been ruled out when trying to track down my 2800 rpm stutter (still need the DME update). Upper and lower intake boot are both brand new, they have maybe 8 engine running hours under them.

As far as I can see, everything is reconnected, but that's something I'm hoping to clear up tomorrow for sure. I'm going to tear it all back apart to look for anything out of the ordinary if no one has any specific places to check... A wiring harness issue is my biggest fear as did see a flat spot on the plastic shielding over the wires right around my oil filter housing...

For the oil pressure code, that is definitely a possibility for both, I suppose. I think it's still the original sensor, so I don't know if that may be going bad, or what. I didn't take it out when I did the CCV work, but I'm not sure I didn't unhook it with how much I took apart to do the CCV and VANOS at the same time. Honestly, I know where the sensor is, but I don't know where the cable connections for it are. I'll roll this in with checking other connectors.

[Aesora]

As for having done a lot already, I'm usually in the role of giving help rather than asking for it, so I wanted to make sure I'd covered every angle I could find just to make sure I wasn't repeating someone else's posts where they found the answers.

[Oli77]

So you did clean the ICV?

[Aesora]

I haven't done that, but I haven't seen anywhere online that it would cause the SES light for the exhaust cam that I'm getting. It is on the docket for tomorrow though once I get enough stuff torn off to get to it!

[Aesora]

New update - ish.
tl;dr - read the first paragraph and the last paragraph, I guess.

My buddy has the ELM327 bluetooth adapter running torqe pro, and we couldn't get it to connect to my car. I now have a half-way functioning laptop with DIS on it, if anyone can walk me through the steps to get the information requested through there.

The second part is the car is back in the garage, torn apart, and I pulled the VANOS back out to inspect it. The exhaust side didn't seem to leak as much oil as it did the first time I removed it, but that may be in my head. The seal on the larger end of the VANOS piston for the exhaust side did feel pretty similar to the factory seal I just replaced as far as how easy it was to slide in and out. My question on this is, if I messed up the installation and fried the new seal on the exhaust side, could that cause my issue if the intake side is functioning as intended?

Another thing I noticed, and I don't know this for sure, but it looks like the two squares on the back of the cams are not at the exact same level with each other. I'm going to put my phone on them to measure them with the level as soon as I have the valve cover off again. Since these cams are connected by a chain which I have not touched and the car ran fine prior to the work, how could this be possible?

While I had the VANOS off, I swapped the exhaust and intake solenoids just to see if that changed anything. After the car sat idling fine for a few minutes when I put it back together, the rough, lopey idle started again and SES came back with the same 28B8 code.

I called GTO Services which is a local indy shop I found through www.bimmershops.com, and the guy said he could probably get me in sometime mid-next week and charges $100 an hour for labor to diagnose it. At this point, I'm thinking that may be my best option. I've replaced everything I could find that could cause this SES code. My only remaining options seem to be if my new cam position sensor was also faulty, the new exhaust vanos piston seal being faulty or otherwise broken due to me, or the two cams connected together via chain somehow came out of time with each other when I didn't even touch them during any of the work. Or I guess if the issue was there before but replacing the VANOS seals and/or CCV and hoses caused it to surface.

Any last minute words of wisdom with not being able to get my buddy's OBD connector to work?

Thank you all for your time. If no one has anything else, I'll follow up with what the shop says and what ends up fixing it as I can't tell you how many threads like this I found where no answer was ever posted.

[Aesora]

Sorry to keep bumping the old thread, but I wanted to add one final update. SHE'S FIXED! I took it all back apart and found there to be barely any oil in the exhaust side piston. So I lubed it up a whole lot and made sure all of the races and piping had oil in them, then slapped it back on. It still stuttered at first, but after driving it and getting on it for about an hour to make sure the oil was plenty hot and pressurizing into everywhere it needed to get, there's no more rough idle and I'm back to loving my daily driver!! Thank you all for your help, support, and interest along the way!

[johnrando]

Glad that worked out.