The world number seven was leading by a stroke with one hole to play three years ago but dropped a shot at the last as McIlroy holed a 16-foot birdie putt for a dramatic victory.
"I'd like to get a win here at Royal Sydney after what happened a few years ago," the Australian said. "That burns a little bit.
"I made an error on the last hole when I couldn't afford to. It was a shame because I'd had such a great run but maybe a good motivator for me this week to get out and try to do it all again."
Former world number one Jordan Spieth is seen as Scott's main obstacle this week, with the American double-major winner back following a seven-week break from golf since the Ryder Cup.
Spieth romped to a six-shot victory here in 2014 with his title defence last year falling one shot short when he and Scott were joint runners-up behind Australian Matt Jones, who is not defending his crown this week.
Scott, who has had a stellar 2016 but has not won since early in the year at the Cadillac Championship, has Tiger Woods' former caddie Steve Williams on the bag and is determined to be in the hunt come Sunday.
"You don't need much more motivation than playing for the Australian Open trophy," he said.
"That's a big one for any Aussie. Even after all these years of playing all around the world, coming back and playing here is a big motivator."