High mile v with shaking

"my thoughts were possibly a head gasket? I don’t really see signs of it though. I am going to double check for any color in the exhaust, and the oil that is in there isn’t new nor super old. NOT “milky” at all. It actually looks pretty good."

Classic gen3 head gasket failure in a 2016 v. Shaking and losing coolant into the cylinder fouling the plugs. Sounds fairly advanced. Rarely gets coolant into the crankcase. Probably needs a rebuilt engine, hopefully one that did not have a hg problem.

 

2016's got the new rings?

@Prius C One, if you do the head gasket repair, or replace engine, do for sure clean the EGR components and intake manifold. If possible post pics of their condition. 330K miles is a surprisingly good run for a third gen, that's only had "religious" dealership service. See first link in my signature.

 

To answer my own question, I believe the inference in "Applicability" (first) section in the attached is that from 2015 model year onward Prius v for sure have the revised rings.

I'm harping on because two possibilities for head gasket failure are commonly mentioned here: the "low-tension" piston rings (on 2010 to partway through 2014 model years), and the EGR carbon clogging.

The regular (hatchback) Prius went to Gen 4 in model year 2016 (with revised engine and EGR), but the Prius v did not follow suit. It did get revised piston rings, but that's all.

 

Yes, the 2016 and 17v's are still gen3. Either the new design rings wore by 330k miles or the many other sad aspects of a gen3 contributed. Pcv, egr, intake, hg geometry, cylinder cooling, all reengineered in gen4. It is possible coolant sealer was used to flip the car.

However at 330k miles it is likely the engine was missing 33 oil changes since Toyota specified 10k mile intervals and most pros now recognize 5k as the safer duration. One of several Toyota Master mechanics who routinely discuss the reasons is ADM of the Car Care Nut youtube channel. His last video shows a 2002 engine which is still extremely clean.

Revised gen4 strategy for even cylinder heat distribution


Finally, since you are not the original owner, it is possible you have an older replacement engine and or the car was used in a taxi fleet. It should have a vehicle matching vin plate on the back of the engine, passenger side. It is likely missing if its a salvage yard engine, a different vin or hopefully, the same vin as the car. A missing or different vin generally means an older engine since few 2015-17 gen3s were made and most survivors are doing well. If it is different, the actual year and engine can be determined.

 

Those symptoms are consistent with unequal clogging of EGR passages of the intake manifold.

 

That's right, IF head gasket leakage has been confirmed by other means (borescope inspection, coolant level dropping, rough starts, etc.).

You said " It ran great and everything but as soon as you put it into gear (Drive or reverse) it shook violently. I Installed plugs. Ran beautifully! Started it today. Little shaking on startup. Went away…. Hmmm….
Put it under load, not as bad but still there, especially at low throttle maintaining speed. Give it power, goes away."

Rough running under moderate load, but not at start-up or heavy load, might be consistent with unequally clogged manifold passages. EGR is shut off at start-up and high engine loading, assuming the EGR valve is functioning correctly. That's all sorta moot, if the head gasket is indeed kaput.