Verstehe ich nicht! Warum sollte ein geschmiedetes Teil zwangsläufig blau sein?
http://www.clubgti.com/showthr…aft-types-and-differences
QuoteThese type cranks are also hardened like the cast types but a different process is now used.
Its known as Induction hardening.
Induction hardening also causes the surrounding journal material to take on colours, similar to the colours sometimes seen when a crank has been heated due to lack of oil.
This colouration is a characteristic of this hardening process and can be alarming when seen for the first time on your own engine.
The colouration can be seen below.