Our 2008 Prius is making a rattle noise when you first turn it on and the gas engine starts. It sounds like a piece of metal is loose. Today when it started up there was a knocking noise when the gas engine started. We just bought this Prius 2 months ago. Any idea what could cause the rattle and now the knocking noises?
Any chance you can record the noise and post it for us? How many miles on the odometer? Cars with over 150K miles can have issues with piston slap when it's cold out - less than 32°F. My Prius just passed 215K miles recently and the piston slap is fairly loud in the first 30 seconds when the temp is less than 32°F. The noise goes away quickly thereafter. A internal combustion engine heats up incredibly fast based on what my Torque app is reading (increases by 40°F in less than 30 seconds when 32°F outside). It's also possible that the gasoline engine water pump in your new to you Prius is making the noise and it's likely to be a bad bearing. The water pump in mine wasn't leaking but it got noisier over time due to a bad bearing. I replaced the water pump last summer. Very reasonable price too. Less than $50. Quiet ever since.
This might be a normal sound that you are hearing. You can find a dealer with a prius and have them start it up. You probably hear the same sound when the ice engine starts. SM-N900P ?
This might be a normal sound that you are hearing. You can find a dealer or friend with a prius and have them start it up. You probably hear the same sound when the ice engine starts. SM-N900P ?
