40 degree F Cold start

Was it that cold this morning? I did not need to go any place until around and did not have anything like that happen.

Im with you on this though, if thats normal at 40 whats going to happen on new years at 3am when i go home and it is -5?

 

Did you happen to the move the car a very short distance the last time you started it (like to pull it into the garage from the driveway) before this mornings startup? If so, do you recall the ICE (gas engine) starting up for just a brief bit?

 

How can you be sure the temperature had anything to do with your startup condition? Is it repeatable, or just a freak occurence? If it's not repeatable as far as you can tell, you probably found a hole in the calibration, which happens with almost every car.

You guys have to remember these cars are tested and calibrated to work from -40 to +85C, and most systems are required to be flawless from -40C to +125C [all powertrain components for sure].

You also have to remember we have barely tarted up Yaris's, which aren't exactly the pinnacle of NVH. Occasionally being reminded there's an ICE under the hood isn't reason to panic. The ICE is still way better behaved than the Chevy Volt, FWIW.

 

Fotomoto is already thing the same as me. The OP's description on the start up shake/noise is the same as Gen III Prius problems with engine shake at start up. My 2010 did it numerous times. It happens when a cold Prius engine is started for just a few minutes or seconds and then shut off. The next morning, when the engine is restarted it shakes quite violently for a few seconds. It is more likely to occur when the temperature is 40 degrees than at 70 or 80. As far as I know, Toyota has never figured out (or has never admitted) what causes the engine to shake like this. Theories for the shake include an overly rich fuel mixture, piston slap, etc. I can say that I owned a 2002 Gen I Prius and it never had the problem.

 

There shouldn't be anything to worry about.

I've had my Prius start rough after sitting outside for 2 days unused and enduring a heavy rain storm. But that's pretty much all I remember. It's been pretty much smoooooth otherwise, even on those days where it sat in temperatures below 0°F all day while at work.

 

search 'cold soak'.

 

how would you describe the humidity at the time? Was it warm and humid the day before? Dew?

I can't believe this is still plaguing Toyota.

 

It was by me and we are in the same area. LOTS of dew

 

As one of the technicians on here mentioned, the cause for the misfiring was buildup of condensation in the intake manifold (caused by high humidity) and being sucked in. The solution was to modify the manifold with ridges to hold the water. They replaced mine this spring and I haven't had the issue. Of course I haven't had a occurrence for two years when it happened to me twice just after I got it (sept 09).

So either they are not putting the modified IM in the C or it wasn't the solution to the problem...

 

Could it be because it's atkinson and not otto cycle. At startup very hard to get enough fuel for initial turning of the engine. And i read somewhere, the way prius starts its engine is much different, it starts 1 or 2 cylinders first, then the other 2, this is why the engine start and shut is seamless when moving?

 

That is a strange occurrence and I will keep an eye out for it in my C this winter. Although I never have had that happen on my Gen2.

 

"Mechanics say the contaminated gas has a sludge-like consistency, which clogs the fuel system. BP is investigating how the contamination occurred."

BP gasoline recall rattles Northwest Indiana drivers - Chicago Tribune

 

I just read an article about that gas! IIRC you are in Indiana? Glad it isn't anything serious.

 

Well that was anticlimactic. Glad to see it wasn't something more serious.

 

probably what they collected cleaning up in new orleans.