Yes, same BASIC engines. GE CF6-xx for DC10 & MD10, MD11 may have either GE CF6-80 or PW4460 depending on the tail number.
MD10 A/C are modified DC10, as stated in a previous post, the airframe is the same but cockpit/avionics mod allows for 2 person flight crew instead of 3 (no flight engineer, saves $$). (in a nutshell)
MD11 looks basically the same as DC/MD10 although a bit larger. (DC/MD10 is 182ft nose to tail and 155ft wingtip to wing tip. MD11 is 200ft nose to tail and 170ft wingtip to wingtip) One very critical difference is the horizontal stabilizer (the tail) surface of the MD11 is 25% smaller. Better fuel mileage but less pitch control. This design feature has been implicated in several crashes of the MD11. (FedEx has had 3 flip over, most recently in Mar/09 A/C N526FE in Narita resulting in the loss of the 2 crew members).