Audi A6 Avant: AKN Engine, 1999 Model

Hello fellow mechanics.
'how to access my profile and some of my previous posts.'
It's fairly obvious, but I haven't had much luck with my A6 so far.
'Or, I was lucky that I bought it from a friendly seller, and so I got almost everything.'
I was able to claim the warranty.
Since my employer is also a customer there, I probably received a special kind of treatment.

So far, the following have been done:
11/2003 (~98,000 km): Upon purchase, the following were replaced: front and rear brakes, and Recaro seats were installed.
12/2003 (~105000 km): Complaint regarding cold start issues and occasional lack of power; no action taken.
02/2004 (~108,000 km): Complaint regarding cold starting issues, intermittent lack of power, 6 glow plugs replaced.
04/2004 (~113,000 km/miles): Valve cover gasket and mass airflow sensor replaced, turbocharger adjusted.
05/2004 (~120000 km): Similar to February, experiencing turbocharger noises, driver's side.
06/2004 (~125,000 km): Turbo replaced, front suspension new, mass airflow sensor replaced, brakes new.
11/2004 (~140,000 km): Brakes on the rear axle functional, rear axle seals replaced (300,-, no warranty).

Now, this masterpiece of German automotive engineering has 150,000 kilometers on the odometer.
There's no more warranty, and I'm increasingly anxious about it.
1. AKN (Application Knowledge Network) entries from 1999 are affected by outdated information.
I missed checking it when I replaced the lid gasket.
2. Rattling noise coming from the area of the fuse holder at 1700-2000 RPM.
Pilot valve for AGR (Exhaust Gas Recirculation) or VTG (Variable Turbine Geometry), or something else? I need to look into this.
3. Maintenance costs (including insurance and taxes) and, above all, depreciation are very high.
4. When I switch vehicles, I will only receive assistance from my trusted dealer.
'a reasonable price, so I'm limited to VAG models. Which TDI engine?'
Which is more robust? ASZ? Newer V6? (Only interested in used cars).
5. Which gasoline engine is recommended (or an alternative using LPG)? 2.0/115 hp? 2.4/170 hp?
6. Which VAG vehicle has previously been known for requiring excessive maintenance?
7. Who is looking for a top-maintained and meticulously cared-for A6 Avant?
No, just kidding, the Audi bank still wants 15,500,- from me .

and 8. Happy holidays and peaceful celebrations!

Now, this masterpiece of German automotive engineering has 150,000 kilometers on the odometer.
There's no more warranty, and I'm increasingly anxious about it.
1. AKN (Application Knowledge Network) entries from 1999 are affected by outdated information.
I missed checking it when I replaced the lid gasket.
2. Rattling noise coming from the area of the fuse holder at 1700-2000 RPM.
Pilot valve for AGR (Exhaust Gas Recirculation) or VTG (Variable Turbine Geometry), or something else? I need to look into this.
3. Maintenance costs (including insurance and taxes) and, above all, depreciation are very high.
4. When I switch vehicles, I will only receive assistance from my trusted dealer.
'a reasonable price, so I'm limited to VAG models. Which TDI engine?'
Which is more robust? ASZ? Newer V6? (Only interested in used cars).
5. Which gasoline engine is recommended (or an alternative using LPG)? 2.0/115 hp? 2.4/170 hp?
6. Which VAG vehicle has previously been known for requiring excessive maintenance?
7. Who is looking for a top-maintained and meticulously cared-for A6 Avant?
No, just kidding, the Audi bank still wants 15,500,- from me .

and 8. Happy holidays and peaceful celebrations!

Hi,

1. Only a very small number of people are affected.
2. no idea.
3. Audi has never been cheap .
4. The new V6-TDI engines have 'almost' stopped having problems.
5. Only interesting for drivers who travel very little.
6. A3 (8P); A6 (facelift); A8.
7. Nope, I have a new one.
8. I wish you that too.

Best regards, Christian.