Gen #3 engine head gasket blew at 254,000 miles and engine hydro-locked

Curious if the BG EPR soak was done with the pistons at mid stroke?

There was an increase in oil consumption after the BG EPR soak?

 

Yeah same story here, much more at my spring drain.

 

You have more cold engine operation in winter, so the engine likely produces more blowby gases then, but the big thing is that since the ambient temperature is lower, more of the water vapor condenses out in the catch can (when compared to summertime).

Posted via the PriusChat mobile app.

 

2 Month Later Update:

Gotta thank @Ragingfit with his FixThatPrius videos! These videos are what I've used to get this baby running!


Llast night I finished, said a prayer and started her up- she fired right up! Sounded like a diesel for a minute but smooth since! No CELs!
While bleeding the coolant, I noticed a small leak under the car under the EGR area..I looked all around and couldn't exactly find where it came from, so I am hoping it's a trailing leak along the bottom from the reservoir area. I'll investigate more later after my shift, but I'm relieved the new engine started

https://photos.app.goo.gl/mUMkLrZyietkZ7eQ9

 

...so last night I traced the source of the coolant leak. I first thought it was the hose that connects from the thermostat to the 'gooseneck' as I saw a stream of pink fluid shoot out after warming up again in Maint Mode. I saw a slice/hole near the end that connects to the gooseneck, cut off a half inch of the hose and clamped it back on, connected the EGR cooler back w the 2 bolts on each side, started her up and saw the hose held....but still leaking. I can see from under the car and from the drivers side with my flashlight a steady drip from the bottom bolt of the EGR cooler where it connects to the exhaust manifold...and as I look closer it looks like a light stream of coolant forming along the bottom seam of the EGR cooler, running along towards the bottom bolt

It appears my EGR cooler has broken. I am not sure if it was during the 4 sessions of OxyClean soaking in a bucket of hot water over the course of a week, or if it was due to me pushing down on it, trying to get it to fit over the gooseneck, hoses and temp sensor during my re-install. This cooler was the original one that came with the car and had approx 19X,XXX when I removed it over a year ago and swapped with my eBay purchased one during my first EGR cleaning.

In all of my time lurking here these past few years, I can't recall seeing a post of an EGR failing from what would appear to be a leak from the weld seams under operating pressure.
I'll take more care of cleaning the eBay one that's been on the car for the last 20k+ miles or so and try again...

 

After cleaning and swapping out the spare EGR, I've found the issue to be the hose clamp not being able to hold on to the hose connecting to the lower EGR cooler outlet. New clamps from O' Reilly's and she's all good now

 

If the extreme heat from the exhaust gases and coolant can't crack the cooler,
soaking it in hot oxyclean won't.
Clamps do get weak over time. I'm glad it was an inexpensive fix for you!

 

Update-
So after driving throughout the week, I've now begun to experience the dreaded Overheating issue via the illuminated High Temp Light and occasional flashing high temp light.
Started this past Saturday afternoon on a 55F sunny day, with my brother in the passenger seat..feeling accomplished that the swap was going well and then it began
Drove slowly home and parked it until last night to where I performed some more bleeding, this time using the Air Bleed screw.
After about more than 45 mins of bleeding while cleaning up, I was satisfied at more stable temperatures at idle, so I took her out for a nice hard shakedown of some hard cornering and some 110mph runs..was pretty satisfied she didn't overheat..so I drove normally around and hit up Taco Bell. On the way back home she started to overheat again!

I parked her and am now gathering the tools to do a coolant pressure test and pressure re-fill.
The coolant bleeding procedure of this car is so freaking frustrating and it's a shame that everything else went through smoothly to then run into a 'simple' problem as this...

 

Are you certain the waterpump is functioning correctly? And the thermostadt?
Did you change them? I don't remember....

Bleeding shouldn't be that difficult. Fill s l o w l y a little at a time. Then add more.
I believe there is a bleeder screw by the brake master cylinder somewhere.
Also, squeeze the radiator hoses several times to help get the air out.
You can also loosen the hose at the highest point to force the air out as you fill.
Out of the hundred of refills I've done I've never had any serious problems filling slowly.
Yes, it does take longer, but less time than having to redue it.

 

Yep, New OEM Gen4 waterpump and New OEM Thermostat.
I've spent some time between Sat and last night squeezing the hoses, using the Air Bleed Valve, feeling the waterpump vibrating and scanning for pending/active codes.

That's fine- I've needed to purchase an Vacuum Air Bleeder/Filler for a while now for my other vehicles, and I'll be going straight to checking the system under pressure, finding if there's any leaks and pressure filling. This should also get rid of the gurgling I've occasionally heard behind the dash as well that I forgot to mention.