Jet like sound from 400E
 

I have been having this question ever since I bought my 92 400E, the car drives perfectly, but each time when launch from stand still, I can hear it makes a special sound, it feels like a jet turbine just starts, "humm...", the sound goes way after rpm reaches 2000.

I am not sure it is from engine or transmission, the sound is not loud at all, it sounds not bad either, but I have never heard this kind of sound from any other car I have driven.

400E owners, is this sound normal for your 400Es?

if that happens when the engine temp is relatively high, then that could be your engine fan.

V-coupling may be locked in place causing fan whirl- jet like sound
-fad