Have had this great product for 2 months now. Had only 1 crash, which was its first flight (2 months ago) with no extreme damage other than a few scratches on the body and not a single crash since then.
The lower left motor sounds really agressive when pushing the left stick right, but when i push the left stick left, it sounds smoothly.
I would also like to add that I have no experience with QC's until I bought this.

Watch the video below and tell me what you think.
I'm quite worried and being a responsible pilot, I wouldn't risk flying with an abnormal motor (If ever).

Any replies/suggestions would be greatly appreciated.

Aloha Denzel,

     Do you get any heat indications from the left rear motor?  I have not noticed before, but you might look in the flight options (Icon at upper right corner on the OSD), the P3 is module is the top one.  Look in there to see if anything is indicated about the motor.  Also the flight information screen when you first connect to the P3 might have a section on the motors with information.  I never noticed that either.

     Of course, it is also possible that something flew into the motor on a recent flight.  Try turn it upside down and shake it when it is off and the camera clamp is on.  Listen for anything loose and see if anything falls out.  Compare it with the other motors.  Geckos also climb in to things like that and then die, so see if it smells.  Does it smell different from the other motors.  Besides dead geckos, rubbing metal, rocks, etc. can also make a smell.

     Lastly, if nothing seems to be out of place, except for the sound, you might consider putting the props on and doing a very cautious flight.  But first, try to note if the motor spins longer or shorter than the other motors when you shut it down with the props on.  Do this a few times before you try to take off.  Since the problem is with yaw (left stick - in mode 2 - horizontal movement), if something is wrong, all the P3 will do is spin.  Slow the spin enough that you can land.  Go no higher than 1 meter in this test and do it over a soft surface like grass or a rug.  If there is a problem, the P3 will try to spin as soon as one skid leaves the ground.  Stop the test before the other skid leaves the ground and land immediately.

     If there is an unusual issue with the P3 wanting to turn one way, that will tell you if the motor is over revving or under revving.  Check with the app to see if there is a yaw setting that was made somehow.  If the problem remains that only the sound is different, you may have something stuck in the motor and the Master Controller is trying to counter the drag of the friction.  This could burn out the motor over time or just sand down the object until it loosens up enough to fall out.  Still the risk of burning out the motor would make me want to not try the latter.  The motor is sealed except for the top, so look inside to see if you can see anything different when you compare it with another motor.  Sorry, that is all I can think of.

Aloha and Drone On!

Sounds like part of the body shell or something is rubbing against the motor.  With the Phantom powered off, turn each of the motors by hand.  Can you feel an equal amount of resistance in each motor?  Did your crash involve the arm that is making the noise?  While there may have been no immediate damage apparent at the time of the crash, after some time and vibration from multiple subsequent flights you now have your current problem.  

A replacement motor will run you about $20 and is relatively easy to replace if you have some basic soldering skills.  The hardest part of that repair will be taking the top off because of all the #*@& locking tabs around the shell (12 total)

Hi,

It sounds that something is inside of the motors or may be you crash hitting that motor and something inside the motor is obstructing the rotation of the motor , what i recommend you is to change the motor , es really easy and you are not going to spend more than 20 usd , so think about it you can fly and may be crash again and lose all  or spend 20 usd and fly with no worries ;)

Forgive me, if he will change the engine will lose the guarantee?