[Foxes]

Hi guys,

I'm at wits end trying to resolve an issue that's been plaguing my N55 ever since I had my DME updated by an Indy.

It all started with a solenoid replacement in my mechatronic unit, the Indy proceeded to update my DME to a newer (Didn't specify) version using a Launch device. This resulted in an immediate rough idle akin to a misfire and what seemed to be pulsating exhaust gasses. Plugged in ISTA and found the following fault code : "101F01 - Air Mass plausibility, calculated air mass in intake implausible" expanding on this code on ISTA it shows a Mixture adaptation fault. Measured O2 values on Ista and they all seem in check as below :
https://flic.kr/p/2mDgNbd


Fast forward, and I've had the following done in hopes that it'll resolve the issue :
- Cleaned MAF and MAP sensors.
- Smoke tested from the MAF, no leaks found. (Pre-turbo)
- Replaced brand new coil packs. (BMW)
- Replaced brand new spark plugs. (BMW/ ZR5TP33S)
- Tried NGK 97506 plugs to no avail.
- Tried unplugging the fuel vent line as detailed in this TSB to no avail. https://static.nhtsa.gov/odi/tsbs/20...63029-9999.pdf
- DME update to I-level F010-21-07-525.
- Walnut blasted all 6 intake ports. (They did look horrible at 110K miles)
- Replaced intake manifold and throttle body gaskets.
- Checked gasket between DME and intake manifold.
- Replaced MAF sensor.
- Replaced throttle body.
- Thorough inspection of charge pipe, intercooler, associated air ducts post-turbo.
- Thorough inspection of vacuum hoses and wiring harnesses.
- Compression tested all 6 cylinders. (175PSI on all 6)
- Checked and cleaned all 6 fuel injectors on a bench in an ultrasonic bath.
- Replaced PCV valve.
- Updated all other ECU's to I-level F010-21-07-550. (No update for DME with Psdzdata 4.31.41)
- Replaced entire valve cover.

It's been 3 weeks and the issue persists, I've tried pretty much everything including the kitchen sink to no avail.
I have noticed however, that when running a Valvetronic "Start-up" on ISTA of 500 cycles, the idle is buttery smooth.
However, upon restarting the vehicle, the issue immediately presents itself.
I logged the values via ISTA and have noticed that upon completing this procedure, my Vanos values and eccentric shaft angles are vastly different than when the engine is rough idling.
If any of you have a copy of ISTA and are willing to log your idling Vanos and Valvetronic values for me to benchmark against, It can be found on ISTA by viewing the ECU tree>Clicking on DME>Bottom right, call up ECU functions> Diagnostics>Select Idle speed + Vanos actual + Vanos Setpoint + Valvetronic angle Actual + Valvetronic angle setpoint.

Right after Valvetronic Start-up, perfectly smooth idle. 180*, full lift?
https://flic.kr/p/2mDpqJm

Right after restarting the vehicle, back to a rough idle 45*, low lift?
https://flic.kr/p/2mDpqHj

I'm theorizing that either the Valvetronic servo motor is out of whack or that the DME is somehow unable to provide the right values for the Valvetronic servomotor to actuate the eccentric shaft, allowing for adequate valve lift and consequently sufficient airflow during idle.
When on the move, the car drives perfectly fine with no issues. Unfortunately, there are no fault codes for Valvetronic issues whatsoever to point a fault at the Valvetronic system.

My question to you is if any of you have experienced something similar and what was the solution to resolve this? I sure hope my DME isn't fried!

[undftdrew]

I went thru the same problem for months tried everything did walnut blasting my self smoothed out the idle but didn't solve the problem then I tried spark plugs and coil packs also did nothing I even replaced my injectors and the problem still persisted the only thing left was the Vanos Solenoids !! they were the culprit change the intake and exhaust solenoid together and it solves the problem totally and its an easier repair than than everything else Ive done to slove the problem space is limited but with the right pick tools it is easy work.

[Foxes]

Thanks for the input undftdrew!

Did you get any conclusive codes pointing to the Vanos system? I might just give that a try, although I don't see any binding or issues with the Vanos system to warrant questioning at this juncture.

Update 23/10/21
Replaced valvetronic servomotor and the issue persists!

[Foxes]

Replaced MAF sensors, MAP sensors, Vanos solenoids and issue still persists.
Anyone?

[Karolx80]

Originally Posted by Foxes

Replaced MAF sensors, MAP sensors, Vanos solenoids and issue still persists.
Anyone?

Hi there! Also having same issue at the moment. When my valvetronic is turned on, having high pressure in intake manifold(~950hPa). Engine runs rough and misfires especially on cold starts. When valvetronic is turned off engine runs fine and intake manifold pressure is about 300hPa and a fault code 101F01 is gone. Also have smoke tested, no leaks were found. Checked all sensors and all works good. Checked the valvetronic servomotor also works fine. Also replaced valve cover but everything is the same. Cant understand why intake manifold has high pressure when valvetronic works. Any thought?

P.S did you solved your problem?

[Bmwdoubles_]

Maybe a silly question but where you getting your gas? Bad gas or too much ethanol without supporting hardware, I've seen these issues.

[Karolx80]

Originally Posted by Bmwdoubles_

Maybe a silly question but where you getting your gas? Bad gas or too much ethanol without supporting hardware, I've seen these issues.

Always using 98 oct premium plus

[Bmwdoubles_]

Originally Posted by Karolx80

Always using 98 oct premium plus

Oh damn where is there 98 oct? Wonder if that's the issue.

[Karolx80]

Originally Posted by Bmwdoubles_

Oh damn where is there 98 oct? Wonder if that's the issue.

Well, then I will try to use 95 octane, but I think I tried it once but not sure. Also not sure if this going to fix intake manifold pressure or valvetronic work.

[Bmwdoubles_]

Originally Posted by Karolx80

Well, then I will try to use 95 octane, but I think I tried it once but not sure. Also not sure if this going to fix intake manifold pressure or valvetronic work.

Is more about the ethanol content. 10% is standard but if you're in an area that is running higher ethanol your car could be complaining about that. However that would have nothing to do with valveteonic issues. And intake pressures could be pointing to a leak which you would need to smoke test for. Also clean your maf and tamp sensors.

[Foxes]

Originally Posted by Karolx80

Hi there! Also having same issue at the moment. When my valvetronic is turned on, having high pressure in intake manifold(~950hPa). Engine runs rough and misfires especially on cold starts. When valvetronic is turned off engine runs fine and intake manifold pressure is about 300hPa and a fault code 101F01 is gone. Also have smoke tested, no leaks were found. Checked all sensors and all works good. Checked the valvetronic servomotor also works fine. Also replaced valve cover but everything is the same. Cant understand why intake manifold has high pressure when valvetronic works. Any thought?

P.S did you solved your problem?

Unfortunately not, rather busy the past few months and have left the issue on the backburner. I have however noticed scoring on my cam journals which could potentially attribute to the issue. Sourcing a donor engine as we speak.

[CBrodskysr]

For what it's worth, if anyone is still looking for information relating to this fault and accompanying driveability complaints:

Foxes: You mentioned in your original post I think, that this started after having some work done which included reprogramming your DME to the latest version of ISTA.
Based on that, it sounds like the independent shop that did the programming/coding did not perform the adaptation procedure which should have been done.


As a test, and/or possible remedy if that's the case, follow these steps:
1. Disconnect the tank ventilation valve (purge valve) electrical connector
2. Allow the engine to idle for 15 minutes
This will allow the DME to readapt faster than during a normal road test.
3. After 15 minutes of idling, reconnect the tank ventilation valve
4. Clear fault memory
5. Road test and verify proper vehicle operation

If the complaint is still present, there is another set of test plans I can let you know about as well.



Hope this helps!

[Houranimd49]

I'm also getting this code on an otherwise stock car (535), and I never had it come up until I brought the car to California filling up 91 oct at Chevron and Costco....

[omer1903]

Hello there

does the problem persist? If it is solved, can you tell me how it was solved? I have the same problem for 1 year and the engine is vibrating excessively. you tried all the ways like you but it still continues

[jimk]

https://static.nhtsa.gov/odi/tsbs/20...63029-9999.pdf

[McGS]

Hi, has anyone found a fix for this issue? I'm having exactly the same issue as the OP. The misfire/rough idle only happens when warm and drives absolutely fine. I've performed a valvetronic calibration and the car idles perfectly after but once I've driven it, it goes back to idling rough.

Any help would be much appreciated!

[Kassav]

I'm having the EXACT issue with my 2011 535i and my mechanic has done all he could, and said he'd have to contact a friend who works at a BMW dealership for help on this issue. I'm a little relieved that I'm not alone and hope someone finds a solution.

Blessings

[flagged charger]

I have this issue with my 535i, and did try those steps, you said there were further steps to take if the code was still there, would you mind sharing them?

[Scottycs19]

Another person with same issue, did anyone solve it?

[McGS]

UPDATE: Plugged the car into ISTA and raised the idle speed by 50rpm's which has stopped the CEL from triggering. Unfortunately the slight misfire at idle is still present though...

Has anyone been able to fix theirs completely?

[Foxes]

Originally Posted by Karolx80

Hi there! Also having same issue at the moment. When my valvetronic is turned on, having high pressure in intake manifold(~950hPa). Engine runs rough and misfires especially on cold starts. When valvetronic is turned off engine runs fine and intake manifold pressure is about 300hPa and a fault code 101F01 is gone. Also have smoke tested, no leaks were found. Checked all sensors and all works good. Checked the valvetronic servomotor also works fine. Also replaced valve cover but everything is the same. Cant understand why intake manifold has high pressure when valvetronic works. Any thought?

P.S did you solved your problem?

Apologies for the awfully late reply, been pretty caught up with work as of late. I did another smoke test and found a small leak that would otherwise have gone unnoticed. Try pulling off the bung that goes to the fuel breather solenoid and smoke test from there. Saw faint hints of smoke seeping through the connection between the charge pipe and throttle valve. Replaced my CP with an ER one and the idle smoothed out a fair bit. However, occasionally I'd still get slight idle sputters albeit greatly reduced compared to when I first posted this issue.
Let me know how it does and if you were able to spot any leaks from your CP.

[Foxes]

Originally Posted by Kassav

I'm having the EXACT issue with my 2011 535i and my mechanic has done all he could, and said he'd have to contact a friend who works at a BMW dealership for help on this issue. I'm a little relieved that I'm not alone and hope someone finds a solution.

Blessings

I've rebuilt my entire engine from the ground up, essentially replacing all my bearings (big and small ends), piston rings, gaskets, seals, and the kitchen sink. Issue still persists albeit to a much smaller degree (after replacing my CP). I believe it may be down to a leak somewhere in the intake track. You'd need to smoke test as close as possible to every connection along the track and have a strong light to spot even the slightest hint of smoke billowing. The method recommended to inject smoke right after the air filter came up inconclusive the first time, only managed to spot a leak when I plugged the smoke detector way upstream at the bung leading to the fuel breather solenoid.

P/s as a side note, I found a hairline crack on my cylinder head during the rebuild. Happened on cylinder 1's spark plug thread. PSA : Follow the torque specs peeps!