Two problems related to engine rattling and whining sounds have been reported for the 2010 Toyota Prius. The most recently reported issues are listed below.
The contact owns a 2010 Toyota Prius. The contact stated that the vehicle was burning oil excessively and the service vehicle warning indicator was illuminated. There was also an abnormal rattling noise when idling. The vehicle was taken to labadie Toyota (located at 909 n euclid Ave bay city, mi 48706) where it was diagnosed that the piston rings needed to be replaced. The vehicle was not repaired. The manufacturer was notified and opened case number: 1707100976, but did not offer assistance. The failure mileage was 296,000.
After car sits for several days engine will idle very roughly upon starting for almost one minute. Idle is so rough that I thought the engine mounts would break and creates a very very loud rattling sound. This has happened three times, two after sitting for several days and once after just sitting overnight.