N52- Valvetronic issues after VCG replacement

[Eins Suchtig]

Hi,
Looking for help. N52 gurus please show up!

I changed the valve cover gasket and related items due to oil leakage after stopping the car for 2 weeks due to COVID lockdown. Well, when I finished the process, using mainly the FCP Euro video, the car started with difficulty, misfires, etc. I turned off and started again. Christmas tree in the dash due to a completely drained battery (about 11 volts). Exchanged for a new battery, car started immediately with some idle hunting. After a few miles I noticed RPM and power were very limited. The limp mode , half engine light came up, but eventually went off. Still no power . I scanned codes (Schwaben/Foxwell NT510). It had a ton of codes due to the dead battery, which I cleared . Drove again and now I still have code 2A39 - DME VALVETRONIC ADJUSMENT RANGE. Cleared the code, did the procedure for setting the max and min limits with the Schwaben/Foxwell scanner, but when rechecking the code is still there. Drove the car and still limited power/RPMs. Repeated several times the code clearing - max/min procedure but the code keeps coming again and no power/RPMs

Any clues on what is preventing the DME from learning the min-max setpoints?

Any sense on clearing adaptations ? Have never done it.

PD; Car has BPC off road tune, AA headers & axle back exhaust, DISA and AFE intake. All mods were done 3 years ago without any issues. Car ran perfect before the VCG replacement.

[Gambeez]

Sounds to me like the motor was installed incorrectly if there was never a problem with it prior to removing it for the VCG replacement. Or something caused your eccentric shaft sensor to go kaputt or it’s dirty.

I did mine and was super careful about putting the valvetronic back together. Only misfire I got after was due to a poorly seated ignition coil.

Hopefully somebody has something else to chime in but that’s where I would start.

[Bimmer-Bob]

Originally Posted by Eins Suchtig

Hi,
Looking for help. N52 gurus please show up!

I changed the valve cover gasket and related items due to oil leakage

What else did you do besides the VCG? Did you change the eccentric shaft sensor or anything else while you were there? Did you replace the Valvetronic motor gasket or just reuse it? Did you inspect coils and spark plug wells for oil fouling?

I don't know that we have enough information to say precisely what went wrong. These cars will get all screwy with a dead battery and throw a ton of codes, but since the Vlavetronic code keeps popping up, I would start there.

[Rmtt]

When you reinstall the valvetronic motor be careful. This caused me an issue. I had screwed the motor into place via worm gear using a 4mm Allen wrench, then fastened the mounting screws and left tension on the worm gear. My engine ran really rough.

I had screwed the motor with the Allen wrench to the point where it had a lot of tension on it and I think moved the eccentric cam.

I removed the valvetronic motor and reinstalled it keeping the 4mm Allen very loose feeling after the motor was mounted.

Went through the relearn process and it was fine afterwards. I didn't use a tool to reset it...just the key in ignition and push start for ACC mode so the engine doesn't start. Let it sit for about 30 seconds....y9ou could hear the motor going through its "learn" procedure.

So I would start there. Pull that motor and reinstall.

[Eins Suchtig]

Originally Posted by Gambeez

Sounds to me like the motor was installed incorrectly if there was never a problem with it prior to removing it for the VCG replacement. Or something caused your eccentric shaft sensor to go kaputt or it’s dirty.

I did mine and was super careful about putting the valvetronic back together. Only misfire I got after was due to a poorly seated ignition coil.

Hopefully somebody has something else to chime in but that’s where I would start.

Thanks . I was following carefully the FCP advise on disassembling and assembling back the Valvetronic motor, but who knows. I will take it out and assemble again, then repeat the max-min learning.

[Eins Suchtig]

Originally Posted by Bimmer-Bob

What else did you do besides the VCG? Did you change the eccentric shaft sensor or anything else while you were there? Did you replace the Valvetronic motor gasket or just reuse it? Did you inspect coils and spark plug wells for oil fouling?

I don't know that we have enough information to say precisely what went wrong. These cars will get all screwy with a dead battery and throw a ton of codes, but since the Vlavetronic code keeps popping up, I would start there.

Hi Bob,
I changed VC Gaskets, Valvetronic motor gasket and eccentric shaft sensor gasket. Didn't touched any of the mechanicals inside. Removed , cleaned and installed coils and spark plugs back. Right now there are no codes for misfires.

[Eins Suchtig]

Originally Posted by Rmtt

When you reinstall the valvetronic motor be careful. This caused me an issue. I had screwed the motor into place via worm gear using a 4mm Allen wrench, then fastened the mounting screws and left tension on the worm gear. My engine ran really rough.

I had screwed the motor with the Allen wrench to the point where it had a lot of tension on it and I think moved the eccentric cam.

I removed the valvetronic motor and reinstalled it keeping the 4mm Allen very loose feeling after the motor was mounted.

Went through the relearn process and it was fine afterwards. I didn't use a tool to reset it...just the key in ignition and push start for ACC mode so the engine doesn't start. Let it sit for about 30 seconds....y9ou could hear the motor going through its "learn" procedure.

So I would start there. Pull that motor and reinstall.

Thanks Rmtt.
I'll follow your advise, to remove-reinstall the valvetronic motor again, paying attention to avoid tension.

[Eins Suchtig]

Found the cause.... Valvetronic motor plug disconnected.... Plugged in , started up and everything fine now. I guess I didn't pushed until it snaps, the 1st time. Lesson learned, double check everything. Thanks all for your responses!

[Bimmer-Bob]

Originally Posted by Eins Suchtig

Found the cause.... Valvetronic motor plug disconnected.... Plugged in , started up and everything fine now. I guess I didn't pushed until it snaps, the 1st time. Lesson learned, double check everything. Thanks all for your responses!

Well, non-op Valvetronic would certainly screw things up! Glad you found the cause and it was such an easy fix.

[paulinoesc96]

hello, greetings to all, let me introduce myself, my name is paulino escalona, ​​I am talking about chile, I apologize if my wording is not the most optimal, and well, I will tell you about my serious problem with my BMW, it is a 525I with an n52 b25 engine
It all started when I bought it, the vehicle came with certain faults and it accused me of vain, valvetronic and thousands of codes, I made the decision to make a complete engine adjustment, the vehicle today has,
new pistons and rings
new main and connecting rod metals
oil pump (not changed)
new gasket and seal kit
new cam sprockets (Vanos)
new timing chain kit
valvetronic new,
new eccentric camshaft sensor
new VVT valves
new coils
new spark plugs
revised injectors
the vehicle since it was put together all new I think it's worse than before it starts very badly, I can't even take it out for a spin because of how bad it is, I'm a professional mechanic but this is already surpassing me, the car is mine, not someone else's client, I have only known how to spend money on this car, well the issue is that I start the vehicle with the valvetreonic disconnected and it runs a little better, in short, it keeps idling with one or two cylinders off but it is a bit stable, (of course not let it accelerate), now when I connect the valvetronic and obviously I erase codes and learn speed bumps, when starting it starts to sound like a tractor and turns off immediately, it doesn't support idling and starts to raise and lower the rpm constantly until it turns off, sometimes it also turns on and it sounds so loud that I have to turn it off, I emphasize the loud knocking noises, it is only if the valvetreonic is connected, I would greatly appreciate help since I am taking out the engine and burning it and installing it a V8 with a carb lol. Cheers