N75 Valve Hum When Engine Off?

Translated on 02-08-2026, 19:44.

Hello.

Volkswagen Golf 4, Automatic Transmission, 60,000 km, manufactured in 2001.

After the engine is turned off, the N75 valve (part number 1K0 906 627 K) hums for about 5 seconds, then the vacuum pressure completely disappears (in the reservoir).

No performance issues, no errors; VTG became commonplace within a year.

Is it possible that the N75 valve is mechanically defective? Why is a 1K0 part (from a Golf 5) installed there?

Best regards,

Translated on 02-08-2026, 19:45.

Quote:

Why is a 1K0 part (from a Golf 5) installed there?

Because it has been replaced before, and I think that only these parts are used as replacements now...