My "NEUER" V8 D11 4.2 and his little quirks

Hello, everybody.

I've been looking for almost 4 hours in total but not really found something suitable.

My NEUER makes almost treble-like or similar noises as when a pump goes tight from the rear right wheel at every step on the accelerator pedal. However, only while the journey was not in progress Can't narrow it down or describe it in more detail.

My temperature indicator is after engine start at 120°C, here only my question of the V8 has nevertheless the hot warning lamp so that man does not miss to make out the engine, or !?!

A 2011 bill shows that the cylinder head screws have been pulled back, but for €0.00 - what could that mean? At 189TKm only oil sweat to the outside as well as with every 3B.
Or does the V8 have problems here?

Then I'm looking forward to your answers
Greetings from the Münsterland
Micah