[E90jacob]

N52 pulsing idle

Recently my car has started to sort of pulse at idle. The rpms will ride to 800 then drop to 700 before repeat it one second later. I have done several things to try and fix it and my last thought is maybe it's the alternator.

Things already done:
Checked and cleaned vanos solenoids
Checked plugs and coils
Checked vanos check valves
Cleaned MAF sensor
Fresh oil change

The video:

https://share.icloud.com/photos/0ae0...47_TTE49WdPGew

been really pissing me off lately

[F31B48]

Any fault codes? You could try clearing adaptions if there's no codes

[E90jacob]

Originally Posted by EvaBmw

Any fault codes? You could try clearing adaptions if there's no codes

No codes at all, also cleared the adaptations and they went away for about a day but they are back in style like they only took a vacation.

[Jros]

when i had similar problems it always was some kind of vacuum leak.
Check your STFT and LTFT fuel trims, if they are way positive then you almost sure have a leak.

Check all of this stuff visually as a first step:

- intake hoses after the MAF
- TB to IM interface gasket
- IM to engine head gaskets
- the infamous Valvetronic motor gasket, who happily leaks even when new and installed perfectly (just use RTV)
- ESS gasket
- all of the valve cover perimeter gasket
- CCV hose and interface points on valve cover and intake manifold

Remember, if oil oozes out then air can get in, so check for cracks and oil leaks.

As second step, you can hook up a OBD2 scanner and set it to log STFT in real time on both banks, then start spraying all of the above zones with *a bit* of engine starter (ether spray) or propane gas, and look if the trims are going richer (more negative).

Do this with a cold engine, idling. If you don't feel safe, have a fire extinguisher ready, but in my experience if you pay a minimum of attention there is no danger.

If the trims move positive and/or your RPM fluctuates when you apply the starter fluid / propane gas, you found your leak.

If you can, the best method of all would be to smoke check all of the intake tract. You can buy a purpouse bult smoke machine, build your own or ask a shop to do it (i would prefer doing it myself to be absolutely sure everything is checked for good).

If you find no leaks at all, i would suspect something not working good in your Valvetronic or Vanos sub systems.

I Hope it is a leak tho, less expensive to fix

Happy hunting

[Jros]

Originally Posted by E90jacob

N52 pulsing idle

Recently my car has started to sort of pulse at idle. The rpms will ride to 800 then drop to 700 before repeat it one second later. I have done several things to try and fix it and my last thought is maybe it's the alternator.

Things already done:
Checked and cleaned vanos solenoids
Checked plugs and coils
Checked vanos check valves
Cleaned MAF sensor
Fresh oil change

The video:

https://share.icloud.com/photos/0ae0...47_TTE49WdPGew

been really pissing me off lately

Another thing: i see you had an oil change lately. Are you positively sure 101% that the oil filter cage was not erroneously discarded? If it was, buy a new oil filter cap as soon as possible and replace it. Running with no cage can damage your Vanos system and gives you all sorts of random crap running.

[E90jacob]

Originally Posted by E90jacob

No codes at all, also cleared the adaptations and they went away for about a day but they are back in style like they only took a vacation.

It turned out to be the alternator overvolting my car.

[Greger]

I did my 323i 2006 year model DISA upgrade and tune and after adding small DISA its idles like in the video. I checked all vacuum leaks and cant find the problem. INPA is not getting any map sensor codes.
I have taken intake manifold off to check all my connections and vacuum houses and nothing. Have new manifold seals and new gasket on MAP sensor.
Thinking to just get other MAP sensor and test it.
Had error 2D06

https://youtube.com/shorts/nOTm-7J0uPk