I have about 1.5k miles on my '07 Touring. Since I got it, it seems that that when the gas engine cycles on/off it is very rough. When I test drove other Prius before buying I didn't notice this, and when I test drove this one I didn't really notice it. But, ever since I bought it I have noticed it. I can understand feeling something when it cycles, but this is really rough. I've been meaning to take in but just haven't yet. Should you normally be able to feel the cycle on/off shake your seat?
Wish I had a nickel for each one of us who asks this. I found it to happen every first shutdown in the morning when I first got mine during the winter (Feb). Seems to have decreased with (1) the warm weather, and (2) the "maturing" of the engine, but still sometimes noticable. Just a little quirk with this car. I want to experiment this winter with putting in the engine block heater - bet it will help since the starts won't be so cold. Once you get used to it and all the other little unique noises you will no longer obsess over it. At first I really thought there was something wrong with the engine. There's nothing wrong - it's just unique and takes some getting used to. Now I don't even notice most of the time. Enjoy your car!
It'll shut down rough if two conditions are met - the car is new (mine took forever before it shuts down smoothly. Even now after 56,000kms, it shuts down rough now and then) - the engine is cold They've done a much better job with the TCH in terms of reducing vibration when the engine shuts off but with the Prius, it can get violent at times and does not indicate a malfunction. (sound like a owner's manual for a second there lol)
When it shuts down it has to do so in a certain crankshaft position and that adjustment adds to the roughness. That is, it shuts down and uses a MG to position the crankshaft correctly. I've felt/heard mine try two or three times before getting it right. Kind of like "sputtering to a stop".
