Coolant in Oil

Rust on the top of your pistons is NEVER a good sign. Neither is the clogged water jackets on that gasket, in the block. Someone dumped 'stop leak' into it?

IMHO; I'd look for another car. Even if your able to fix this with a head gasket, there's a good chance something is bent and you'll have cooling system issues in the summer months. Mainly due to the stop leak blocking your coolant system and making your heat exhangers inefficient. Coolant in the intake could be a leak in the EGR cooler. Other issues may also be present; cracked and/or warped head and/or block; since the car has been running w/o coolant. When you blew the heater hose, you pumped all the coolant out of your engine and radiator. It has an electronic water pump, so as soon as your key-on; it fires up that pump.

Sorry...

 

The change or rebuild engine light just came on.
The path that the coolant took to get to the oil sump probably didn't happen because of something in the HVAC loop.

A head gasket is like a circuit breaker - or more appropriately, a fuse.
In Priuses they don't fail because 'the head gasket went bad.'
The head gasket was gasketing, and trying to keep your bottom end from hydro-locking.
THAT is what all the shaking was about (Prius Death Rattles are......aptly named.)
If the coolant passages are clogged with pepper, bars-leak, unicorn hoof shavings or whatever was used in an attempt to keep the coolant from getting into the oil - then I'd just get a replacement motor, rebuild it, and THEN fix whatever got all of this started in the first place - probably the EGR loop and/or intake.

I'm not a good enough wrench to know if you can unclog coolant passages, but for an engine with Lunar mileage?
I would not want to bet a rebuild's worth of time, parts, and sweat-equity on finding out.

Good Luck!

 

The head gasket does have coolant to cylinder compromise on all but cylinder 4. That's not a happy engine.

 

15 years and 250K miles is a good run for "any" car...if you catch my drift.

 

+1

 

Can you explain the discoloration in the block coolant, #1-2 vs #3-4, counting from top to bottom. Pictures 2-4. There was definitely something going on for that discoloration and build-up to take place on just those two cylinders. Looks like calcium deposits, water instead of antifreeze; but weird thing is that it didn't effect #3-4. Those two running hotter than the later or is it just the angle of the picture?