Diesel sound?

Doesn't sound right to me. You're not running it on lpg or cheap petrol by any chance?

 

I would get it checked by the dealers, especially as it's a new car. Better to get the car checked incase it turns into a more expensive problem.

 

First, the Prius never shifts, so it isn't an issue of which gear you are in. There are no shiftable gears in a Prius.

The Atkinson Cycle engine in the Prius uses a fairly high compression ratio for a regular fuel gas engine. To get efficiency, the Prius pushes the mixture and timing to the limit. This results in the engine sometimes sounding a bit like a diesel. It's completely normal.

Tom

 

I respect what you say but sometimes it can sound like a diesel? You sure? Apart from 10 seconds when it did that cold start problem when stood for a few days mine has always run sweet and super smooth and quiet for a 4 pot engine. It has never sounded like a diesel ever and I work mine hard.

I use the European standard premium unleaded 95 octane (87? US octane) not super 98 actane.

I know I'd take mine straight to the dealers if it ran like a diesel and get them check for any error codes etc.

 

By sounding like a diesel, I mean that rattly sound that diesels make; the one that sounds like a few loose screws in an empty tin. Certainly the Prius doesn't sound like a big tractor diesel or something from an earth mover. On occasion it will do a little more rattling than what you might expect from a normal gasoline engine. It shouldn't do it all of the time, and it shouldn't be terribly loud, but once in a while under the right loading is normal.

The lack of engine compartment sound insulation probably adds to the effect.

Tom

 

I have never heard any rattling sound ever on my 2010 Prius. Currently have 3,500 miles. Run standard 87 Octane gas.

 

It could be the infamous dash rattle mistaken as engine noise.

 

I would try running a full tank of higher octane gasoline. The Prius has a very high compression ratio. Gasoline formulations vary state-by-state in the USA; I have no idea how they may vary in Europe.

Can't hurt much to try.

 

Compression ratio is 8-something. That 13.0 ratio is exhaust expansion, not intake compression.

 

Thanks so much for your posts, you just saved us hours and hours of hassle. We had exactly the same problem after the dealer did exactly the same software job and made exactly the same error of not putting in the hood prop (what's up with that?). I just went out and checked under the hood, and lo and behold there was one end of the prop lying on top of the engine. Test drove, and purrs like a cat.

By the way in case anyone else is wondering about whether they have the problem, I thought the sound also sounded like detonation or "pinging," though it was a bit deeper than normal pinging.

Love the forum,
:rockon:

Marcus Corbin

 

Yep...Same here...