Toyota death rattle upon start up coolant loss

When you took the o-ring off the Degas bottle you're now running zero pressure like some trucks do with special coolant because of that zero pressure you have no pressure forcing coolant past the head gasket into any given cylinder especially when the vehicles running now when it's just sitting overnight a little will seep in just because that's what water does so you've proven to yourself that you have a head gasket problem because when you remove the pressure from the water system your problem more or less cleans up immediately when the pressure is there it accentuates the rattle well it actually forces water into the cylinder which causes a miss with accentuates the rattle The rattle is the engine and the transmission internals are getting out of sync mechanically or something and your pounding the springs on the end of your torque plate and all kinds of fun stuff It will literally break your center girdle of your engine it'll shake the engine to death make a rod throw whatever and tear everything to pieces in pretty short order if you're not careful.

 

After removing the spark plugs if you look down into the cylinder you'll likely find
the #1 and #2 pistons look cleaner they the other two, or at least #1 does.
You likely have a failing head gasket between the #1 and #2 cylinders.
The ONLY way to fix it, IS to fix it, by replacing the head gasket.
DO NOT PUT ANY OF THE SO CALLED HEAD GASKET SEALER IN THE COOLANT!
The cost of replacing the head gasket will likely double because you're clogging the radiator,
heater core, coolant pump, thermostad, and all the little passages...

Coolant leaks into the cylinders as the engine cool and the coolant eases in because the
coolant tank is under pressure. Remove the coolant tank cap only released the pressure so that
not as much coolant leaks into the cylinders.

Removing the cap, and squeezing the radiator hose then closing the cap "might" minimize the
amount of coolant loss. But all these things are NOT a cure. And will only get worse.

If you continue to drive it like it is, it WILL be worse and you risk bending a connecting rod and/or
throwing a rod and/or piston through the block.

Save as much money as you can as fast as you can, borrow it, whatever you need to do and find
a shop that KNOWS about the Prius and how to repair it CORRECTLY.

I take it you do not have the ability to repair it yourself? The expensive part is the labor.

 

how can the car continuously run without entering ice mode?