After a two hour drive yesterday I shut off the car and came back a minute or two later and there was a whirring noise like an electric motor somewhere under the vehicle at the passenger rear wheel? Free Electric Sound Effects made available for personal non-commercial projects. These sounds do not come with a license for commercial use. If you have a commercial and professional project it would be wise to license professional sound effects. The main source of noise is going to vary from motor to motor. In a lot of motors though a big one is 'cogging' where the strength of the magnetic field that is seen by the armature varies as it spins. This causes it to cyclically twist on the shaft and this makes some of the noise. Also, bearings are likely to be another major source. Return to Category List Return to Category Homepage. Royalty Free Music and Sound Effects Search It sounds like a sensor problem inside the motor. Check the wiring connection from motor to controller. If the hall effect sensor in the motor has failed, your best bet may be to use a sensorless controller. About O'Rourke Electric. Established in Parry Sound for over 30 years, O'Rourke Electric has been an exemplary business supporting the community. Commencing Jan 1st 2013, O'Rourke Electric is owned and operated by Les Purcell, who will continue to maintain the quality reputation that Bob O'Rourke has built over the past three decades.