Ok, I give up. Why is it still overheating!?
98 v70 turbo awd. New TD0419t turbo, timing belt done by PO 15k ago. Unknown (but assumed) they did water pump.
I have replaced: Thermostat, ECT sensor. I have filled up the reservoir. Warmed and cooled like 4 times until it stopped getting lower. I did multiple pressure tests, reclamped a few hoses until it would hold 20psi (about double what you need to try) for an hour+. Tightened a few leaky hoses which hold now.
So now, it will be fine a few days, coolant won't be any lower at the end of the day, but then on day 3 of commuting (twice this has happened) it will suddenly have a coolant loss, then even after topping up at work will be overheating by the time I get home 45 mins later. And once cooled it will be empty in the reservoir (but some may have boiled out).
I have left the pressure tester on when running and it doesn't increase, therefore the head gasket is not leaking (at least not badly)
I took the new thermostat back out, it opens around 190 on my stove.
I cranked for a couple seconds with the thermostat cover removed, coolant shoots out so the pump works.
My OBD says temps range 190-220 max after a long turbo run.
The engine fan works, though not sure what temp it's supposed to come on at, I'd assume sooner.
I'm using basic green coolant (safer for aluminum than orange).
WTF!?!

 

i think I might bypass the heater core in your situation.

 

it doesn't appear to be leaking. Why?

 

Did you test or replace the cap?

 

Replaced with junkyard cap. It definitely holds pressure. Not sure how much. It also definitely releases pressure at some point.

 

Still no answer here. I can't drive my car! Any other ideas?

 

still having the problem. Bump for more thoughts?

 

Cracked coolant surge tank, cracked heatercore, cracked radiator, etc.