I did it !!!! I got the IR with DC motor working. I have put a ceramic capacitor on the DC motor and that made the noise go away. I used a 100nF capacitor. I had been reading about it but months ago I made the mistake not to use the right capacitor. I realized this after lots of reading and googling where the point of using a capacitor always popped up as solution. The clue was to use a ceramic capacitor. Don’t ask me why. I will now have to clean up my code and try to put back my car again because I had removed lots of pieces to come to a basic circuit with this issue to exclude other potential causes. Thank God it worked.