Is there a problem shutting down the ICE before it has warmed up?

Might be. When I roll the car from the garage to the driveway, I'm cognisant that the only reliably available EV mode is the 10 seconds or so at start-up. And I manage, almost always, to stay in that envelope: "start" the car, get out to the driveway, shut down, before the engine fires up.

Regarding "almost always", a month or two back I screwed up, the car's engine did start, ran for a few seconds, and then I shut down. The next regular startup, at engine startup it shook badly. Shut it down and restarted: shaking was gone.

There seems to be a cause-and-effect here. Not 100% predictable, but increased propensity. So best to avoid.

A couple of hail mary requests to Toyota:

1. Increase the EV grace period at start up to (say) 30 seconds.
2. Get some engineers on this startup shake issue, swapping intake manifolds (the current patch) seems to be doing nothing to alleviate it.

 

in the longrun that might give you some knocking at startups/
I'd just let it finish the warm-up cycle; you use a little bit of fuel, but avoid other problems/

 

What did you do before you had a Prius?

 

If I can jump in: with previous cars I would slip the car into Neutral and give a push with my foot out the door. With slight downgrade, that worked at least to get the car in the driveway.

The rub being the Prius transaxle and it not being possible to get it rolling without start up.

 

I'm sure it will add extra wear to the engine since you are basically starting it and not driving it. Considering if you keep clean oil in the car it can last up to 300k miles I wouldn't be worried. It's not like you are doing this everyday. I have 4 cars so I have to move mine sometimes like you mentioned. If not letting my car warm up was my biggest problem I would be a lucky man. Lol

 

On my previous cars, I moved them without warm up. I don't see why a high tech modern Prius would need a warm up. However, there are more than a few posts on here about a loud knock when the engine is shutdown before it warms up. This has never happened to me so I continue not allowing the engine to life warm up. We know the engine doesn't like being cold. It is best to drive moderately when cold instead of warming up the engine.

 

My 2012 has never done it, despite owning & driving it about 50% longer than my 2010, which did it two or three times. So it feels to me as if the problem was fixed or reduced on the later design.

My driveway slope is shallow enough that I can also push manual transmission cars back into the garage, albeit with considerably more effort than rolling them out. And I did set wood blocks out as tire stops.

 

i would let it run for a minute. if you get the knock, keep increasing the warm up time. if you don't, stay with a minute.
at least you're not in minnersoder.

 

I move my gen 2 in and out of the driveway without the engine. I'll put it into ignition on (power button twice) and put it into neutral. I can then coast out of the driveway in neutral without the engine firing up. Once I'm in the street, I'll put the car in ready mode and immediately put it in drive to pull it to the side of the street. You can also put it in drive, get moving and build some inertia, and then put it in neutral to coast. The engine will not start in neutral. Just be sure to put it in neutral before the engine starts and you're gold. Also, when you go to turn it off, don't put it in park and then turn it off, just press the power button in neutral. Also prevents the engine from starting.

 

Interesting. I will try that Neutral trick, did not know that. In my case I would still need to shift to D to get car back into garage, have a bit of a grade. But for backing it out yeah.

 

i don't recall this neutral idea being proposed before. could be an easter egg.

 

If it works it's ok as long as you can roll it (Fred Flintstone Mode). If you need propulsion, you still have a bit over 10 seconds of EV, after start up.