high engine coolant temp, no heat in passenger cabin

all,

have searched a LOT of the articles pertaining to this situation, still having issues.

first background: G2 car has 215,000 mi and recently got P1121 scan code, so I replaced the coolant control valve. that's when high coolant temp and no cabin heat started.

on CCV top nipple connected to hose that had a dot on it and hose goes under inverter cover on right, next nipple down went to hose slightly to left of first hose, bottom hose goes to thermus can. initially ran car in diag mode with high heat, no heat in cabin.

so I got a Autel 519 scan code reader and I see now that the only code is a P0505 (idle air control malfunction)

taking car down my road for short test run, I turn off cabin heat completely and watched the ECT. after a while it climbs to around 220, then while engine is running quickly goes to 245F then 260F.
at that point in time (around 245F) the high temp indicator lights up, temp stayed at 260ish so I return home.
with car in park, cabin heat off - the temp returns back down to 220F. if I rev the engine temp again climbs.

I have gone through all suggestions, open radiator bleed valve, manually 'pumped' coolant hoses, turned on/off high heat in cabin and finally with car off removed and jumped the CHS multiple times for about 20secs.

Have purged the coolant system over period of days and coolant appears to be full as level is near top of radiator cap, no bubbling, no gurgling.

However 2 mentioned problems continue... I am starting to suspect coolant thermostat but it would seem strange that it would go at precisely the same time as coolant control valve.

Have appt at dealer, but it is 60mi drive and feel uncomfortable with the drive when temp stays high, so unsure if it is ok to drive at this point.

Pretty much at end of my wits and looking for suggestions.

 

I used new SLLC coolant and fan appears to 'kick in' at about 205F.

Actually the P1121 alarm threw about 100 mi from home, took it slow and limped my way back. Travel up mountainous road capped speed at about 35mph.

 

I think I finally figured it out - I looked at where the grooved belt that drives the water pump and IT IS NOT THERE!!!

that explains how NO water is being circulated.

does anyone have good pictures and procedure on how to replace?

 

Thanks for the link, I replaced the belt today and got it tensioned, was actually pretty simiple and easy to perform.

This is definately something to check, unfortunately with the P1121 alarm I was focused on the OTHER side of the engine compartment.

At the time that I lost the belt I was accelerating onto highway, at the time I thought I heard something, but rationalized that it was a bump or something, then alarm started sounding off. Luckily for me that day it was relatively cold out (about 35F) and it appears (so far) that no damage was done to possibly warping head from heat.

Actually up till a week ago I did not know that the Prius had ANY belts. Silly impression now that I know that there is a single belt - and it drives the water pump.

All's well that ends well, now getting back to attempting to get to 300,000 miles!