Loud buzz when inserting the key
I have a 2005 159 JTDm 16V.
I have noticed that sometimes (say 1 of each 10 turns on), the car makes a LOUD buzz or humm noise at the front, just when inserting the key. It does that for 2-3 seconds and then the noise stops. The car starts and behaves normally after that if I start the engine.
When it does this, if I remove the key and try again before starting the engine, it consistently does the noise again, as many times as you extract/put the key. I have to crank up the engine and then next time it won't do that.
I have heard of some other cases (with 8v engines) in the Spanish forum, but no one know why this happens. It is really clear, not the normal buzz of the fuel pump, small motors, etc, not at all.