No Heat After Multiple Tries? Gen2 07

Hello I'm new here, have been driving this car since 2017. Recently replaced the coolant control valve with an aftermarket model and then had the Toyota dealer do a flush and coolant change on the engine coolant system. Everything was just fine for one day and then I lost heat. Since then I have replace the coolant control valve with an oem version and immediately after I added more fluid and left the cap off the radiator to bleed, jumped the CHRS, and let it idle on maintenance mode with the cap off and the bleed screw cracked open. Still nothing. No codes anymore though. Tomorrow I am planning on jacking up the passenger side and trying the process all over again. Not confident that will help. I'm wondering if something got lodged into the heater core after my first day of functioning Heat, but I hear that this is pretty rare on Gen 2s. What else should I do?

 

Thank you very much. I was wondering about something getting knocked loose as well. All hoses are warm/hot though. Is flushing the heater core if it is clogged a horrible endeavor. And the thermostat is fine as the hoses are warm and it will not overheat even on the highway. Thanks either way.

 

I am 99% sure the hoses are correctly reinstalled although I forgot to take a picture before hand. The top hose is the shorter one and the slightly longer one is on the middle, and the large one obviously on the bottom? No white dots on mine as they got wiped away at some point. Thanks for the reply very much appreciated.

 

Again thank you so much for being so accommodating and posting this info, tonight I am going to find out about the heater core by checking the temp of the hoses, I just had the dealership take another look at it because I asked them for some tips and tricks and they said to bring it back in and rebled it for free because they believed they left an air pocket in, but that was not the case, they are suggesting that the heater core may have a clog, which is what I was worried about but again I also have heard that this does not happen too frequently with the Toyotas.

But yes other than checking the heater core hoses everything else gets up to temperature eventually, the top hose on the coolant control valve is probably the least hot but it is still noticeably warm. Definitely hot coolant inside of it. I'll have to take a look at the temp blend thing tonight if I can get it back from them but I believe it's fine because I can hear it moving.

Finally has anyone ever done a heater core flush on one of these Gen 2 Priuses? If so what is the easiest method for accessing the hoses enough to connect a garden hose for a flush? Cannot find any videos on it for this car specifically.[/QUOTE]

 

What's also strange is that I am poking around right now and it seems like the air coming out of the vents is slightly warmer than outside temperature but only when the engine turns off, as soon as the engine turns on you can feel the vent drop by about 10 degrees

Just checked heater core lines and it's very clearly warm on the right side and barely lukewarm on the left

Can I do the garden hose flush on this type of heater core?

 

I was hoping to flush the heater core first and then try to replace that heater pump because that was on my radar, I read somewhere else that that was somebody's problem. I'm hoping that I can flush it because you know that's almost a free option, but a genuine pump or even a knockoff is kind of expensive for what the car is worth. I just checked the blend actuator and it definitely moves the little plastic arms around when I change it from cold to hot.

Unrelated: I've never been on a forum for maintenance advice before and I have to say I just can't believe how nice some people are to take the time to respond and help others, I hardly have the time to ask these questions so it is very much appreciated.

 

So to recap here replaced the coolant control valve twice, after that I had a Toyota dealership bleed it and then I came back to have it rebled after not having heat after a day of driving once I got it back, that didn't do anything and tonight I just flushed the heater core and the heater pump still absolutely no difference. The car has been such a pain since this problem started I think the real solution is buying a DC 12 volt heater and seeing how many more miles I can get out of it.

 

Service techs professionally flushed and bled the entire system prior to the heat stopping only days after this was completed. And prior to that I had installed an oem coolant control valve. Last night I just flushed the heater core and the heater pump no luck, still seems like the heater core hose going to the engine is not warming up. Should I do an entire reflushing of the coolant system? Although the car is still throwing the coolant control valve error code I've replaced the thing twice and paid quite a bit to get an oem model so I guarantee that is not the issue anymore. Doesn't seem to be the heater core either, and if I am correct that heater auxiliary pump shouldn't matter even if it's broken at least while you are running the engine, coolant should still flow through it, just not when the engine is not running that was the impression I was under. Thanks again.

 

It was taken to a Toyota dealership to do the flush, just for the ICE. I decided to have them flush and refill after first installing that coolant control valve and everything worked fine up until the day after I got the car back. When it left toyota there was heat though. And yeah thanks for the link, I have already driven the car almost certainly gotten it up to temperature on a 40 minute drive still no heat. Maybe I could try to loosen the bleeder cap and rev it up instead of just leaving it in maint enance mode. And yes essentially all hoses will eventually get hot after a while except the hose on the left side pipe connected to the heater core. I pushed distilled water through there, through the aux heater pump and out to the hose that connect to the top of the coolant control valve. Coolant seems to flow freely, but still no heat today after my drive. All hoses hot except the left side heater core hose.