V engine knocks morning start for 1 minute

how many miles?

have you cleaned the egr circuit?

 

You need to provide codes that are there half the time as a starting point.

Describe symptoms in detail. When did shaking start? How often? Have you replaced any parts yet?

 

C'mon, just the miles on it, please?

Could be it's just getting started. Again, divulging the miles on it would help.

Just editorial:

Is your car a 2010 Prius, level "V"? If so you might want to report the intitial post (button below the post), and ask moderator to move; this is a "Prius v" forum, the larger version Prius that debuted in 2012. FWIW, the mechanics are more-or-less the same, at least for the purpose of this discussion.

 

Without sharing codes very few of us will share free advice. A dealer won’t require details, they will just charge you $150-$200 for a diagnosis.

I get it, you may not have a scanner and don’t want to pay a dealer to diagnose. A hybrid is not the easiest thing to diagnose.

Since I am being charitable today and responding, yes, there could be no noticeable coolant loss if it was a cylinder to cylinder leak, a bad egr valve sticking (unplugged is not enough to block flow), a very unlikely plug/coil/injector fail just at startup (those problems continue and code with large misfire counters) or the result of a normal head gasket failure that happens by the thousands in 2010-15 Prius engines.

How does a normal hg leak not show coolant loss? It seals up the very minor leak on startup. The leak only occurs when the cooling system is pressurized and the engine has cooled off, typically overnight. It could be four drops once in a while.

Someone could have put in stop leak at some point and it is wearing off.

Feel free to change the plugs, coils and injectors. Replace the egr valve and software with the newest versions. Or swap parts around watching the misfire code locations. Shotgun it. Even this is better with a capable scanner.

 

Sell it...............