[Hotter]

Hi, my BMW 328i N52 is having rough idle, vibrating seat/steering wheel. Also engine startup is a bit rough too.

I thought vibrations were due to valve cover oil leak (I thought maybe that causes vacuum leak), but changing valve cover/gasket and fixing this oil leak did not help.

Additionally I have changed spark plugs, MAF, front engine mounts, but that did not help either.

It seems that tachometer show idle ~580 (I believe previously when everything was ok it was showing higher idle at exactly 600) even though INPA is showing idle at ~650.

It has rough startup and vibrates on both hot/cold engine. When driving engine is smooth, no issues.

Could it be vacuum leak? I tried disconnecting MAF, it seems that it does not change much, engine is running similarly. So could I do an assumption that its not vacuum leak?

How could I diagnose if its fuel injectors?

Any other ideas?

Currently I just increased RPM so it idles smoother, but I would like to find the root cause.

[R.Thillman]

Originally Posted by Hotter

Hi, my BMW 328i N52 is having rough idle, vibrating seat/steering wheel. Also engine startup is a bit rough too.

I thought vibrations were due to valve cover oil leak (I thought maybe that causes vacuum leak), but changing valve cover/gasket and fixing this oil leak did not help.

Additionally I have changed spark plugs, MAF, front engine mounts, but that did not help either.

It seems that tachometer show idle ~580 (I believe previously when everything was ok it was showing higher idle at exactly 600) even though INPA is showing idle at ~650.

It has rough startup and vibrates on both hot/cold engine. When driving engine is smooth, no issues.

Could it be vacuum leak? I tried disconnecting MAF, it seems that it does not change much, engine is running similarly. So could I do an assumption that its not vacuum leak?

How could I diagnose if its fuel injectors?

Any other ideas?

Currently I just increased RPM so it idles smoother, but I would like to find the root cause.

have you tried unplugging your coil packs while the engine is running looking to see if the engine hesitate or bog down when the coil pack is unplugged? IF it doesn't make a difference when you unplug it then you probably have a bad coil pack.

[bluewater328]

What codes are you pulling?

Did you replace the ESS when you replaced the valve cover?

Did you consider pulling the VANOS?

[Hotter]

No codes, no errors, INPA is showing that engine is running smooth, so mechanics are saying that its ok... although seat is vibrating on idle.

I did not replace valve cover myself. What is ESS?
I bought this one: https://www.autodoc.lt/vaico/12249066
And mechanics replaced it. Thought they had isses to replace it. First they did not use sealer on gasket, so there were massive shaking, they changed MAF, cleaned vanos solenoids, when finally added sealer on valve gasket which fixed massive shaking, but not these smaller vibrations on idle.

By Vanos you mean vanos solenoids? Forgot to mention they were cleaned too, but did not help.

Should I just drive and wait for codes? Even though its already quite some time passed and I am not getting any codes... I dont think I will... at least for this issue.