Our 2010 Liftback got the dreaded 'knock on cold start'.

I wouldn’t do anything til you have time to do the whole egr circuit

 

Sorry to hear, mine knocks when outside temp is lower than 40 degrees. Hopefully it's fuel injectors that needs cleaning, techron fuel injector cleaner for the tank.

In your shoes, I'd inspect the egr pipe. It's the canary in coal mine to see how much possible accumulate carbon build up. It takes less than 15 min to do but will reveal how soon (or how long you can put off) the cleaning of entire egr circuit and manifold.

 

@farmecologist you say you got the knock first thing in the morning. Did the car happen to have a cold start and very fast shut down (say a minute or less run time) just prior, say the day before?

Apart from the EGR, yeah clean the intake manifold and install an oil catch can? Still, EGR goes hand-in-hand with this.

 

Go for the oil catch can .

I bet you’ll catch a lot.

 

Only thing, it shouldn't be thus, that a simple behaviour one day, not that unusual, brings the car to it's knees, the next day. The Prius, 3rd gen in particular, is definitely "special needs".

 

Depending on the battery charge, you can hit the "EV" button so the engine won't start if you are only rotating vehicles.
For me, it works 99% of the time. Even with just 2 bars showing, depending on where the charge is for the 2 bars.

 

Maybe your climate helps? I find EV is AWOL 99% of the time, even in summer, with a cold engine. I don't even bother trying it anymore. The only time I'll use it is if the engine's been run in the last few hours, it's still partially warmed up. Pretty much just a novelty.

 

One of the first threads I read here was that is the oven starts, let it run until it stops.
So even if you are only moving a little bit, wait for the engine to shut off before turning the car off.
Move of the time I do that, but if it starts just as I'm ready to turn it of, I turn it off.
Only once did I have a rough start. But I knew what it was and just let it run until it shut off.
Haven't had it happen again.

Here if Florida, I get EV with a cold engine. And moving it out of the drive way to rotate cars I've always been able
to use it, unless the battery is too low. And I'm only going about 10-20 feet, at less than idle.
Now if I'm going somewhere, as soon as I hit 10mph, no matter how slow I go, the engine kicks in.
Other than that, it's pretty much useless for me. I can work the throttle and go 40-42mph on the battery only.

 

I'm here to report that the infamous cold-start miss+rattle syndrome stuck my Prius for its first time yesterday morning. That was alarming! Ambient temperature was 43 degrees F (possibly the coldest start this fall so far). That was two days after it last ran, with a rainy day (if that matters?) in between. The last time it ran was a 15-mile trip at mostly low speeds, NOT a very brief run time, as sometimes seems to be associated with the misfire. No maintenance or disassembly of EGR-related components yet, at only about 93700 miles.

I received the ZF3 notice in September, 2016. "Primary" coverage is long past.

The EV trick would be more useful if it were not restricted to warm conditions in the US. That goofy restriction has the dual effects of INCREASING air pollution, and increasing contamination of the oil whenever an owner needs to move the car a very short distance. Why???

 

NOTHING wants to run when it's cold!

 

Yikes welcome to the infamous club. How long was the knock? Mine knocks below 40f cold soaks. No EGR & manifold cleaning done yet but will get to them in couple of months w OCC.

 

You always have around 15 seconds of EV after startup, fwiw. Keeping my runtime to 10 seconds max (just counting in my head) I move ours out to the driveway in one pop, or out onto the street in three. Start up, get into gear fast, move. Shut down, Repeat as needed. 60 seconds would make it a LOT easier.

 

You mean the time from pushing start until the engine comes on? That's more like 5 seconds... I can get about halfway down my driveway.

 

Maybe time is slower up here.

 

It’s just a Canadian thing.

Or is it retired time?