2018 Prius 2 rough ICE start

Sorry I can't offer any sound advice, but welcome to Prius Chat.
There have been various posts on here about the symptoms you have experienced although I can't find any to quote for you. Somebody Stateside is bound to come back to you before very long.

 

Was that a pun?

 

Oops! Genuinely unintended, nice catch.

 

I think it's normal - if the engine is cold. Think of a "normal" car, you'd hop in, turn the key - and, it's not what you'd call smooth - the starter turns, the computer (or choke/accelerator pump/ignition retard on old cars) sorts out what is needed as far as timing, ignition and fuel supply to kick the engine into life. Even more exciting in a diesel.

PRIUS, [assuming there is Hybrid Battery charge and that the heater or A/C isn't intervening] instead, starts with some very quiet space-ship like whistles, clicks and whimpers, you put in reverse and it reverses out your driveway silently except for the crushing of leaves in the driveway.

You drive along the avenue, still it's in silent EV mode, the battery decides it's helped you along enough, or you've put your foot on the accelerator more than gently - and it decides THEN to start the cold ICE. Basically, it connects it to the transaxle and it spins - while concurrently, the injectors squirt petrol (I'd assume a richer cold-start ratio), the ignition starts firing - and it's noticeable.

So what you're experiencing is the same as starting a cold engine - but while you're driving along in a relatively quiet car. After that first start, you'll barely notice the engine starting and stopping - just the first time - but it's stopping and starting continually.

 

really? the gen 4 engine is experiencing rough start issues? wow.

 

I wouldn't call it rough.

It's just like the normal start on any normal ICE car - just that it happens while driving along silently, not when you turn the key. It's noticeable first time after starting/re-starting.

 

gen 2 and 3 aren't. (except the gen 3 egr problem)

 

I could feel it when I test drive a Corolla HYBRID which uses pure Gen 3 ICE & Hybrid tech - I had been talking to the salesman about it and it was noticeable - but we were listening for it.

 

i can hear and feel the engine come on, but my wife can't. but i think there o/p his talking about something rougher, since it is already warmed up, and only happens after a/c use and the car turned off.

 

Do you shut the car off while the ICE is still running? It is better to let the ICE shutdown on its own before powering off the car. Exactly what do you mean by "rough" ICE starts? Does it shake/clank upon starting?

 

I've never worried about that - but I generally turn the Climate Control OFF when I stop, particularly overnight.

 

Rough starts usually occur (on the next start up) after the car has previously been shut off, whilst the engine was running, before the first warm up cycle had completed. This is a well known feature of some fuel injection systems, I had a Ford Mondeo which did the same.

 

i had not heard this about the gen4. that's too bad, i thought they might have solved it.
has anyone reported it here?

 

It's much less noticeable on the Gen 4, i.e. nowhere near as rough and it goes away after a few seconds.

 

Obviously still under warranty, and assuming you'll draw it to their attention: post what the dealership says.

 

Yup.....that's been my experience also......

 

amazing toyota can't fix this problem, must be the quest for mpg's.

our hycam doesn't do it, i wonder if the new one does.

 

I think Camry has more sound insulation - PRIUS' claim to fame is light weight, max fuel economy - and the sound insulation has only been applied where it's really needed.

I figure they're not concerned about a fairly minor noise/vibration which happens once for 2 seconds after every start - better to put that kg of insulation where it's going to have more usefulness.

 

if it's just 2 seconds after every start, i would agree. kithmo is saying differently. hopefully, o/p returns to clarify.