KARCHER K 5 1.180-633.0 - Low pressure, vibration of the washer and hose

Hello, there is a problem in the form of low water pressure, the stream of water seems to be intermittent (very fast pulsation), the hose vibrates significantly, it is trembling all over, you can also feel vibrations on the lance. While I set the pressure to low, you can clearly see that the water is not flying smoothly, as if air is being supplied instead of water, after disconnecting the hose and lance from the washer and turning it on, it still behaves like a vibrator.
As it is already after the warranty (30 months from the purchase), I took apart a bit and apart from water mixed with grease, I found nothing with oil, where to look for the cause?

Buddy, did you manage to do something about it? Because I have very similar symptoms. Hose vibration and low pressure. I took the washcloth apart ... and nothing looks suspicious.

One of the valves was loose, it was disengaging, I really glued the super glue, washed the center with new oil, and so far it works.
If the situation repeats, I will replace all valves with new ones.