Miles and decisions.

Has the EGR cleaning been done before?

SM-G981V ?

 

sounds like a sound plan

 

I'm no expert, but the HG on my 2011 failed at 232k, and again at 241k...both of which happened before I bought it. A friend of mine owned it and replaced the HG each time without having cleaned the EGR cooler...he didn't know...neither did I. The HG failed for the 3rd time at 248k, I did that one 1300mi ago and I also installed an OCC and cleaned the EGR cooler which was plugged solid.

Everything except the oil consumption you described I also experienced in the weeks leading up to the decision to dive into this.

Make sure you check the head for a warp, replace the valve stem seals, and check for a bent rod, but I'd say it sure sounds like the HG has given up the ghost.

SM-G981V ?

 

Yes, a weekend could do it. Just depends on how much trouble any of the fasteners give you and how many times you would have to stop and Google something.

SM-G981V ?

 

Unfortunately, oil burning and head gaskets have become chronic on gen3 Prius engines. Even some dealer mechanics are acknowledging the scope of the problem.

Before I did anything I would consider the rest of the car, eg what else will it need? Are there any other common trouble spots like the hv battery and the abs system that are still original? Is the car's overall condition worth the repair? What is the kbb private party value in good condition?

The problem is the engine is worn out (eg oil consumption and miles), has a bad head gasket (which warrants a lot of new parts while you are in there), may need a machined head (which will add downtime and cost), no doubt has a clogged egr cooler and may also leak oil.

Just doing the head gasket with $500 worth of gaskets and fluids may disappoint when the oil keeps burning and perhaps other coolant and hydrolock related problems reappear. Especially if the car was run for any period of time since the rattling started.

If the car was worth it, I would buy a low mile complete engine and have it rebuilt. Depending on the market, some have had this done for $3k-$5k, although dealers may ask $5k-$7k. But the car ends up with a like new engine, no leaks, no oil burning and no rattling. Plus factory mpg and another 150k worth of reliable engine life. With a low mile rebuilt engine, a clean car would easily add $3k-$5k of value at resale.

 

Plan on completely cleaning the EGR, and intake manifold too, or you’ll likely have another blown head gasket shortly, as alluded to by @Dilbone. Info:

Bad Flywheel | PriusChat

The oil consumption can be cured completely by swapping out the (low tension) piston rings (piston replacement a necessity too), for the revised rings/pistons specd for model year 2015. The most expeditious albeit more expensive route would be a new short block, an assembly consisting of everything below the head gasket. The assembly sells for around $2k US. Labour obviously extra. Info:

How bad is the oil burning issue 2010 to 2015? | PriusChat

 

nothing at @NutzAboutBolts ?

 

@Gasket masters suggestion: get a beefy wrench and socket on it, with wrench handle pressed against solid metal on the “unscrew” side, and check ratchet is set for unscrewing as well. Then have someone kick the engine over, for just a split second.

They demonstrate this in a how-to video, which sadly they have taken down.

 

My 900 ft-lb of torque impact wrench wasn't budging mine at 100psi on my regulator...had to bump the regulator up to 120+psi before it finally broke loose.

SM-G981V ?

 

Considering there’s no belts on the pulley, is the torque spec overkill? And/or if they’re really concerned about it breaking loose, lower torque spec and some sorta Woodruff Key??

 

I’m thinking it’d be good to make jig for locking that pulley. Toyota makes a special tool, but it should be possible to cobble something, that locks on the pulley, has a lever arm that can bear on the garage floor ((or adjacent car body) and allow you to get a socket on the retaining bolt. Sure you can just slam it on with the impact tool, but if you want to apply the correct torque.

 

Actually they have a new hg video up today that shows this technique clearly.