Thought My Prius Was Going To Blow Up

Rough starts are usually misfires, and these cars are usually very good at catching and recording misfires (as error codes).

And there aren't many reasons why one of these with so little usage would be misfiring. New fuel source lately?

 

any chance when you parked in the new place, you shut down the engine while it was still warming up?

 

During this, did the engine start and run just for a few seconds before turning off?

 

@bisco & @fotomoto beat me to it. This typically happens after shutting down the engine before it's warmed up. Happened once to my wife with her Gen 2. She never did that again!

 

this has been an ongoing problem for all prius up to gen 4. not sure if they fixed it in that gen.

what happens is that because of the design of the intake manifold and other considerations, when you shut the engine down in certain circumstances, unburned hydrocarbons remain in the manifold.
upon the next start up, they get drawn into the combustion chamber and cause detonation. (blow up)
when you have to move the car, etc., try to let it warm up a few minutes before shutting down.

 

I was remembering that moisture condensation was also involved.

I don't remember full warmups being needed, it was more associated with a stone cold engine running only a few seconds before shutdown. E.g. after cold reparking where most of the move is done on pure electric, then the driver doesn't quite get finished before the automatic engine startup. The next startup was when it infrequently might occur.

My 2010 vintage had many reports of this violent shaking, and I suffered it several times. Now if I don't quite finish a quick move before the ICE starts, then I let it run at least 20 seconds before shutting down. There was some factory change before my 2012 was built (and a TSB for older units), reducing the problem. Between that, and changing my habits to avoid it, I've never experienced it on my 2012. But a 'c' isn't quite the same.

 

I haven't managed to encounter this problem myself, but I have read about it for a while on Priuschat. Apparently falls under "harmless" and "scary" at the same time.

 

Me as well and I have also done cold start and shut down a few seconds after the ICE started just to move the car. I wounder what other criteria there is that causes the event?

 

i don't recall the c having this issue, i had thought it was immune.

 

Don't confuse this problem with the rough start from antifreeze intrusion that you get on the big 2ZR engine. The 1NZ in the c does not get that problem, fortunately- but if I have it right it seems to have the same "rich start runaway" that the same 1NZ engine also displayed in the older 2nd generation Prius.

 

It was quite infrequent, so I never fully understood the whole situation on the 2010 liftback either. The great majority of the cold brief start-stop cycles did not produce this problem.

 

Right. It doesn't always do it. My working theory is that it does it when there's enough liquid left in the intake manifold to get sucked in on startup which leads to it very nearly hydrolocking.