Shaking at 2800-3000 RPM, engine revs past 4000

Hi,
I'm not sure if this is normal behavior. When you slowly increase the engine speed while it's idling, it starts to shake and feel sluggish around 2800-3000 RPM. If you press the accelerator further, nothing happens, and then suddenly the engine jumps up past 4000 RPM. Is this normal? While driving, you don't notice anything unusual except that the car is generally very slow. What could this be, or is it normal?

Hi,

Too much oil in the engine?

Best regards, Rainer.

Hi,
No, the oil level is between the minimum and maximum marks.

What occurred to me this morning while driving on the highway: Could this phenomenon also be caused by faulty oil pressure switches? For example, if the oil pressure becomes too high? Perhaps an oil pressure switch in the filter housing is defective and only reacts at 3000 RPM, while the switch in the cylinder head doesn't react until then.

Or is everything I'm imagining here just nonsense?

@reuselkopp:
I think you are confusing the function of a pressure relief valve with that of a pressure switch .
The pressure relief valve is located on the pump and prevents excessive pressure buildup. The oil pressure switches on the filter flange and in the head only indicate the presence of pressure that exceeds the switching level.

But even if your pressure relief valve were defective, oil wouldn't necessarily enter the combustion chamber as a result. More likely, the radial shaft seals would fail first.

Regards,
Alex.

@donelaxo,

Yes, you are right. After doing a little research online, I realized my mistake.
Is the sudden increase in engine speed an indication that oil is entering the combustion chamber?
Das komische verhalten ist aber doch nicht normal. Der Motor startet kalt sehr gut und warm eben AFN Typisch ein wenig träger. Im LL läuft er auch normal. Nun gibt man im Stand Gas...die Drehzahl steigt ab, ca. 2800 U/min. quält sich der Motor, so als hätte er überdruck. Man gibt weiter Gas und die Kiste schüttelt sich (es ruckt so als hätte er leichte Zündaussetzter), man gibt weiterhin mehr Gas und die Drehzahl steigt aber nur ganz leicht an bis sie bei ca. 3000 ist und dann auf einmal ohne weiteres Gas geben schnellt die Drehzahl hoch bis über 4000. We"Then, when I release the accelerator again, it regulates the low-speed mixture without any problems."

What could it be? That's why I thought it might be related to the oil pressure, which can be too high up to 3000 RPM and then suddenly drop.

Possibly the crankshaft housing ventilation is blocked.
The pressure builds up until around the year 2800, at which point it becomes so high that it will...
Obstacle overcome?

bastion wrote:

Maybe the crankshaft housing ventilation is blocked? The pressure builds up until around the year 2800, at which point it becomes so high that it will... Obstacle overcome?

But then it shouldn't be reproducible. Have you ever used a VAG Com to observe what happens at that moment?

Perhaps the hose is pinched or kinked.

Hello,

donalexo wrote:

But even if your pressure relief valve were defective, oil would not necessarily enter the combustion chamber as a result. First and foremost, the radial shaft seals would likely fail.

Okay, either I've missed something, or you're believing an old wives' tale. Since when has oil pressure been acting on the Simmering rings? The engineer who designs something like that should be fired. When the pressure regulating valve is defective, oil filters have already burst or pump drive shafts have broken, but crankshaft seals usually leak due to excessive (gas) pressure in the crankcase (due to a faulty crankcase ventilation system).
Best regards, Uli.

Hey everyone,
I logged some measurement data blocks related to my problem. In the first block, the values are 002, 004, and 008, and in the second block, they are 003, 008, and 011. What do you think of these values?

For measurement series 1.
Within the specified RPM range (2800-3000), it's quite noticeable that something is wrong with the injection timing. The engine speed then suddenly increases at the same throttle position.

Regarding measurement series 2.
The boost pressure is consistently too high or always exceeds the target value.

Do you have any ideas? When I look at the injection start point using the timing checker, it's slightly above the centerline. Injection start at 53 with a temperature of 119.

Oops...

Either I entered the wrong value for the charging pressure , or I wasn't paying attention last night. I looked at the charging pressure again, and it actually looks great.

Greetings.
Reuselkopp.