[Eron]

The motor on my 20 EX makes a growling sound when under load. Most noticeable when slowing on regen level 3. This is not associated with the low speed noisemaker. I drove a 20 EX Premium and it was much quieter. Anybody else notice it?

 

[MetalHead]

Doesn't sound right.
Should be nothing more than a "turbine" like whine under load (accelerating/regen).
Should be no different to different trim levels. Drive train is the same.

 

[Cavo]

See this thread

Check your motor type number. if it is 710, you´re probably in for a new motor.

 

[niggle]

Driving after reading this thread, I suddenly thought I could hear growling, then I was overtaken by a Ducati


(Hope the OP has a quick and easy resolution of any problems)