S8 V32 warm engine clatters

Hello.



I have an S8 Bj 1997 V32. ==References== 1.5 years I have the following problem:



With warm engine (water temp. 90 degrees for > 20 minutes) I hear a clattering in the engine, which seems to come from the cylinder heads near the windscreen.



The following repairs were made in connection with the noises:

- Timing belts with water pume and all rollers as well as dampers new.

- Hydros new (Hydros only in outlet, inlet fixed or vice versa).

- Oil retention valves new.

- Camshaft control chains new.

- Visco clutch cooler fan new.



Engine is running fine and the noise is no longer noticeable from 1500 rpm. With thicker oil (20W60 Motul) the noise comes only at higher temperatures, at 0W40 from Mobil almost immediately after starting.



Spark plugs are definitely fixed. I'm already driving about. 50000km with the sound. Noise is definitely motor speed dependent.



VAG and engine specialist have no diagnosis. They could just try it. By the way, the test run without secondary aggregates (Lima, ...) did not change the sound.



Currios, here's the thing, at the outside temp. > 30 degrees and fast driving, i.e. The engine is really hot, the noise gets quieter again, but does not disappear.



The sound sounds a little like hydros (but are new and ok) mixed with a noise from the water pump (but is new and ok). I'm not talking about the injection valves, by the way.



Compression okay. Oil consumption < 0.5 liters at 3000km. mileage 190000km.



I'd be happy if someone had similar experiences and if the sound was normal.



greetings



A. Wolf