One problem related to diesel engine has been reported for the 2011 Toyota Prius. The most recently reported issues are listed below.
On Jan. 18th, 2014 I was leaving FL to return to nc, when I started up my Prius and waited for the gas engine to start, it did not want to start. It sounded like a diesel engine, making a loud knocking noise and the whole car shook. I turned the car off and then restarted it a couple of times, but did not experience the issue again. I drove back to nc and did not experience the issue at all. The car was due for maintenance, so b-4 taking it in, I researched the issue online. I found numerous people that have experienced the same problem on the "priuschat. Com" web site, there were also links to youtube vids that showed the same problem. I also found that there is a TSB out for this issue, but it only covers certain vins and the dealers usually require that they can duplicate the problem b-4 they will perform the TSB. The repair is to replace the intake manifold, but this does not appear to be resolving the problem. The problem appears to have started with the 2010 model with the 1. 8l motor and has yet to be resolved.