2010 Prius problem with shudder

how many miles on her?

has the egr circuit been cleaned?

 

Hi
Do you know where the coolant leak is and that a traction pack module is actually bad?
Can you do any of the repairs yourself or will you be taking the car to a shop to have the car worked on?
I ask becasue if it were me, I'd start with the coolant leak.
Than I'd see about doing something about the battery module.

First I'd want to plug in a reader to look at any possible fault codes from the cars main computer, ECU
A shop will usually check for these codes before starting work on the car.

I put the first thing third becasue it may take some time to have fault codes read and if you are able you could start with the coolant leak.
If I were closer to your location I might be able to help you figure out how to get the codes read by someone.
Or you could buy an inexpensive ELM327 bluetooth adapter online
then install one of the prius apps that read codes
than list any codes shown here.

I think DrPrius might be a good app for a phone to connect with the ELM327 ODB11 bluetooth adapter
I've also read here that carista is a good option
it's both the carista ELM327 bluetooth adapter and the carista app.

If the car still shutters after you have done the other things than I'd worry about that then.

 

Don't get your hopes up if there is a coolant leak and a misfire
Those two symptoms together sometimes point at a head gasket, if I'm not mistaken
Hopefully, someone more experienced with a gen2 or gen3 can be more specific.

It's best to hook up a scanner and look for fault codes.

Now it makes more sense what the first mechanic said about pulling the engine apart, if the head gasket is leaking coolant into a cylinder or two.

But if the coolant leak is somewhere easier to fix, that would be a good reason to be optimistic.

edit: and yes a blown head gasket would cause the car to shutter, forom what I understand.

 

google egr and/or egr circuit, and read the priuschat hits for gen3. whether your head gasket is blown or not, it should be cleaned.

 

Lots of info here:

Bad Flywheel | PriusChat

 

Hi all, new to Prius Chat and need to pick everyone's brain just a bit.
I have a similar issue as above stated.
A little history on my 2010 prius basic:
257K purchased from a friend with suspected blown head gasket. Purchased the car with CE codes PO301 (I think) which is a Cylinder 1 misfire which is super common with these cars. I went the PIA way of firs cleaning rhe EGR circuit, did not replace cooler (just cleaned) and intake manifold also cleaner, etc. After all this the car behaved for a few days but then back to the shudder at start up and CE code PO301. I was not about to put approx 4K into a car that cost me 1500 bucks. So I did what a lot of mechanic disagree with, I threw a bottle of K seal into the coolant reservoir and lo and behold, minutes later the car never shuttered again. Almost 8K miles later yesterday happens.
Engine starts stuttering slightly under load, a few minutes later the shudder is back with a vengeance. Oddly there are no CE lights or anything serious on the dashboard.
Could it be that the head gasket has now given out completely and the car is is done? Coolant levels are still right at full and have not moved. Could it be that the intake and EGR circuit are so clogged that it's causing this issue and not throwing any codes?
I'm not ready to throw in the towel.
I thank you all in advance for any thoughts, prayers, humor and banter.

 

My 2 cents:

The shudder is caused by head gasket failure. The head gasket failure is primarily caused by elevated combustion chamber temps, which is due to clogged EGR.

At this point, head gasket replacement is paramount. When that is done, ensure full EGR circuit is clean, to prevent a repeat.

The sealant can hopefully be dissolved and flushed with a 50/50 vinegar water mix.

The EGR cleaning should have happened by 100k miles; by 250k when you acquired it the head gasket failure was likely well underway.