One problem related to engine knocking noise has been reported for the 2010 Toyota Prius. The most recently reported issues are listed below.
At about 125k miles, my Prius nearly ran out of oil between services, and I religiously service my vehicle. I burned 1 to 2 quarts between services since. At 272,408 miles, I just paid $5751. 59 for a complete engine rebuild. . . Rest of car is in great shape. Oil consumption problems were known by the dealerships, but I was given no recourse except dealing with it. Latest issue. . Check engine light on, misfire on cylinders 1 and 4 (progressing to all), horrific knocking noise with sound of rushing water upon start-up. Eventually, (once the cylinders fired significantly) the engine could run satisfactorily for the remainder of the drive. . . Until the next start. Early on I read that Toyota knew of the under-engineered motor of the 2010s, but I have not received anything announcing a recall or care to fix their engineering issue. I have my service records to validate the care I've given to my car. The date of the engine rebuild is what I will provide as to when this happened, but the oil consumption began years ago.