Acceleration issue

Could just be the engine turning on. Usually it is seamless, but sometimes it kicks.

 

Like the guy above says it's probably just the engine firing up. I suppose it depends on your definition of shuddering and shaking or whether you mean vibration. If it is more vibration then I would say it's normal. If the car literally shudders and shakes violently, then this doesn't sound good at all.

 

When you pull away from a stop, often your engine is turned off. The initial acceleration is from only the electric motor. Sensing that you need more power, the Prius starts the gasoline engine. Engine starting with the Prius is very smooth, but you can feel a shudder or vibration as it kicks on.

Tom

 

That sounds perfectly normal. The car does seem a little rougher when the engine fires up on an incline. Obviously struggling slightly with powering both the car and starting the engine. It is normal and I find it isn't quite as bad if I use the hill start assist (when stationary press harder on the brake pedal until the traction control light flashes and beeps. This holds the car for about 2 seconds after you take your foot off the brake).

 

No, not strange at all. Think about starting the engine in a normal car. It is accompanied by a bit of a fuss. The Prius uses a large, powerful motor-generator to do the starting, so it is much smoother, but it would be unreasonable to expect it to be undetectable every time it starts.

Rather than wondering why you can sometimes feel the engine restart, instead marvel at the fact that it is usually so smooth.

Tom

 

My car had done this three times. once at around 10k miles, and two times on my recent road trip i have over 30k on my car now. these three ICE start ups are very different from the normal shudder/shake of the ICE starting. it's like the ICE has bad gas, or is missfiring, it's not running normal at all, it kinda goes power/no power, power. To make it stop i let off the gas pedal, causing the ICE to shut down, then push it back down and all is normal again. I have never been in a hurry, but next time i'm going to just give it more gas to see if it smothes out.

unlike the other posters what i have noticed is not "normal".

 

My car does this about 50% of the time when turning a corner - I know exactly what you mean!

Usually, the scenario goes something like this:

Approaching a turn. Decelerate using light braking to ~30 km/h.
Execute the turn, releasing the brake and getting on the accelerator, lightly.
Accelerating at a constant rate, 2/3 to 3/4 of the way up the HSI, and completing the turn.

At this point, at somewhere between 30 and 60 km/h, there's a definite, defined "flutter" coming from the engine/powertrain/motors. The gasoline engine is already on at that point, so it's not the engine "starting up" (I know what that feels like!).

It's one of those things that there's no way I'd ever be able to describe to a tech - or they'd just look at me and scratch their heads. So I don't worry about it. But, it's like a minor chest or heart palpitation - it makes me nervous, every time it happens.

-Iain

 

Check if the Traction Control signal flickers when the hesitation occurs. When turning and accelerating a slight slippage of the outside wheel will trigger the Traction Control and your Prius reduces the drive train output momentarily. This effect was more extreme in earlier models (like my 2004 )

JeffD

 

Yup!...Same here, the ICE is either misfiring on several cyls. or it is rapidly starting/stopping, (I call it "Stuttering")....My 2005 Gen.II never did this!....

 

You just described my symptom. Same exact thing. Studdering/shaking or very slight jerking i put it. ONLY on left and right turns.

I am thinking it's the tires. Since my L/F outer wall is bald.

who knows

 

Has anyone followed-up with Toyota on this?

I'm noticing it more and more (now that it's happened more times I'm always feeling for it)... I can get the car to "not" do it by altering my driving habits (cornering slower) but I like to hold my momentum through turns. 40 km/h city-street radius turns seem to be about the worst. I'd describe the sensation as "cogging" and I'm fairly certain now it's a software/motor control issue completely isolated from the ICE. It's analogous to hiccups that I see our programmers at work deal with when commissioning servomotor-driven systems, where there's a lot of tuning involved in getting the motors to respond to control signals properly when they see unexpected loads.

-Iain

 

people who say this is 'normal' mystify me. it seems to be more of a genIII thing as far as i can tell. i know what my engine sounds/feels like when it fires up. it's not always the same, but it's never so different that it makes me think something is wrong.

 

I have also experienced this. It has been a long time since it last happened, but I know exactly this sensation. It reminds me of an old car I had that had a faulty carburetor.

 

Are all you guys suffering this issue on the gen3/2010 Prius 100% sure you have 0w20 oil in?

When the dealers inadvertantly filled mine with 5w30 oil I got hesitation and stuttering when the engine fired up. I would describe it as stumbling.

Just a thought.

 

As I understand it, the Canadian cars take 5W20, and that's what mine has (I'm in Canada).

Very interesting, though...

-Iain

 

Do they specify 5w30 in Canada and northern US States because of the cold weather?

Is it possible to try 0w20 and see if it cures the issues you're having?

When I had 5w30 in my Prius (and it's neither hot or cold in the UK) the car was almost undriveable to me as the stuttering, stumbling and hesitation in town/city driving was annoying to say the least.

It was said that if the thicker 5w30 oil got hot it would be ok, but my car is used in town and didn't have chance to get hot that often on quiet days or where I did lots of short journeys.

 

Canard,
Toyota Canada does not recommend 5W20 (or 30) for Canada. The cars ship from the same factory in Japan with 0W20 Synthetic, as the ones going to the US. The service promos on Toyota.ca also list and recommend 0W20 for about $50. The dealers push 5W20/30 here because it fits better with thier normal operations (a wild guess, cause I really don't know why they do!) - if you request Synthetic 0W20, mine here in Mississauga started with a $75 quote, until I showed them the ad from Toyota.ca and they hummed and hawed and did it for $50.

In any case, the point is that I have had both types of oil over the last 9 months, and I still have this issue, and have been reporting it to the dealer, and they vary between "unreproducible" to "normal behavior" and "have you ever driven a hybrid before".

Can those of you who have reported this problem comment on where your fuel consumption indicator is during all this? (on the the Canadian display thats the one that shows current consumption in L/100Km) -mine is always topped out when the problem occurs, even though the Hybrid System Indicator remains within the ECO range.

Below is the last submission I made to my dealer to describe the problem in writing:
.......ICE [Internal Combustion Engine] runs at full power (showing 10L+/100K) when vehicle is at low speed, causing engine to shudder (reported Oct 13/2010). To reproduce, when ICE is at normal operating temp, slow down to stop, and then keep going at low speed before ICE auto-shuts off (as at a STOP sign) - ICE will remain stuck at full power, even though car is going at <20-30K/h and power usage is reported in ECO zone. Condition only corrects itself if the car is brought to a complete halt and ICE is allowed to auto-shut off.......

 

Try adding a complete fuel system cleaner such as Techron or Gumout with Regain to your gas. It may just be a dirty fuel injector that causes a power imbalance. I notice that my Prius starts smoother after I do this, every 5,000 to 7,000 miles.