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Heater issue! No hot air. Read many forums. Heater core hose not hot!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Fliebly, Feb 18, 2020.

  1. Fliebly

    Fliebly New Member

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    I’ve been trying to self diagnose my heater problems for the last couple of days. 2007 Prius pretty much my work commuter. My heater stopped working after I let it set because I was waiting on the time I could replace my struts. Did that, but now I’m trying to figure out the no heat problem. I’ve read many posts about the issue. I have no codes. I know the heater hose from the heater core pump that wrap around the engine connects the fire wall is cool after running engine. I’m just trying to figure out if I would get a code for the heater core pump going out. I’ve read most people get a code. I’ve purpled it like Wong suggests. And don’t hear gurgling. I was hoping someone would steer me in the right direction. It’s winter and I want heat!!!
     
  2. valde3

    valde3 Senior Member

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    Engine coolant looks good? Nobody has used a leak fix in the system? Just a bad heater water pump can't cause this as it's not needed when engine is running.

    You could try flushing heater core and heater water pump to see if they're blocked. If they aren't it could be a bad coolant control valve or something related to it.
     
  3. Fliebly

    Fliebly New Member

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    No leak fix. I haven’t flushed it since I owned. 160000 miles. Bought it at 80000. I’ve been reading about a black foamy substance clogging up parts. So I started with thermostat first thing replaced. I’m pretty sure it had a new radiator at some point because salvage title. It runs good. It was still probably overdue for a flush. Just trying to figure we’re to start. I was reading another post were you responded about disconnecting hose blowing into the heater core hose with radiator cap off. I just can’t isolate why my heater core hose from heater core water pump to coolant control valve is cool even when coolant temp is at 199 degrees. That’s why I think I’m clogged at heater core or the heater core water pump.
     
  4. valde3

    valde3 Senior Member

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    That hose being cold means that there's no coolant flow through heater core. That test was to see if heater core or heater core water pump is clogged. Problem could also be a bad coolant control valve (or something related to it) as it diverts coolant flow from heater core to thermos.
     
  5. Fliebly

    Fliebly New Member

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    Wouldn’t that throw a code for either especially the coolant control valve. I have a generic scanner. Maybe mine just can’t pick up the code.
     
  6. valde3

    valde3 Senior Member

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    Normally it would but perhaps it could fail in a way that wouldn't. I have only worked on European model Priuses so I don't have that much knowledge about heat recovery system as European models don't have it.
     
  7. Fliebly

    Fliebly New Member

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    I just flushed the heater core. I don’t believe it was clogged. It had some tiny black foam pieces but don’t think it was enough to be the culprit. I was trying to flush the heater core pump to heater control valve loop since I already had the hose off the heater core. I disconnected the hose off the control valve. I could not to get any antifreeze or air just by blowing through the loop to pass through the heater core pump. It should flow through freely, correct?
     
  8. Fliebly

    Fliebly New Member

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    I just pulled off the heater core pump. It was 100% clogged with this black foam. It looks like insulation foam. I’m clueless as to what is eroding like that. I wonder if the other pumps are starting to get clogged too! I put it back together and I am going to try to get the air out of the car. I’ll keep y’all updated.
     
  9. valde3

    valde3 Senior Member

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    Yes you should be able to blow through. Maybe not freely but you should be able to. So you tried to blow into heater core water pump from hose that comes from coolant control valve? Did you open up the system at any other point? If not then it could be blocked at any point. If you had the radiator cap off it has to be blocked at heater water pump, heater core, engine block, radiator, or hoses. After that test you could try to blow in the heater core from hose that comes from heater water pump. If you can do that with radiator cap off that would prove that heater core, radiator, and related hoses are fine. If you can do that with radiator cap on then that proof that only heater core water pump is clogged.

    So heater core water pump is clogged. Did you clean it? Or replace it? Did you try blowing though afterwards? I think you should do tests before filling it up as filling and bleeding will take time (and money if using coolant).
     
  10. pasadena_commut

    pasadena_commut Senior Member

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    If it were my car I would drain that loop, disassemble it, and push a lot of water through every component until no more black foam bits appear anywhere. It doesn't seem likely that insulation foam is forming all by itself inside the plumbing, much more likely that somehow or another a chunk of it was left in there, somewhere, and it is now disintegrating causing the problems you see.
     
  11. ChapmanF

    ChapmanF Senior Member

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    I wonder if it's real insulation foam, or something-that-reacted-with-something-else and made what looks like insulation foam.

    Where have you been reading about said black foamy substance?
     
  12. pasadena_commut

    pasadena_commut Senior Member

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    Could it be a hose disintegrating somehow? Those are black and rubbery, although not usually foamy.
     
  13. Fliebly

    Fliebly New Member

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    I cleaned it. Took it apart and used a power probe to make sure it was working. It was such big pieces too. It makes me think there is still some in my heater core. I flushed it and back flushed twice and only a few pieces came out. I took off my inverter pump and heater control valve pump too. I read on here several people have found this black foam in their radiators. There is several recent posts too. I thought about it being a disintegrating hose, but it is spongy like foam. I can blow air around the heater loop. I’m gonna re-flush the heater core. It doesn’t sit right me now because that piece came from the heater core. I could flush it but when I flushed out the water with antifreeze it stemmed like it took less than two quarts to get the water out. I figure there is some more foam in this system. I think I’ll switch the water hose to flush all the loops.
     
  14. pasadena_commut

    pasadena_commut Senior Member

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    Do you have a picture of this material (with something for scale)?

    Can you estimate the total volume of this foam material you have recovered?
     
  15. Fliebly

    Fliebly New Member

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    It was enough to completely clog the front housing hole of the auxiliary water pump. I'll see if I can find some on the ground were I cleaned it tomorrow.
     
  16. valde3

    valde3 Senior Member

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    Inverter pump? That's a totally different coolant loop. You have the same stuff in there two?

    In engine coolant loop:
    Engine itself should be pretty easy to flush with water hose if you first remove the thermostat (very easy just two bolts). Radiator should be easy two flush at the same time (but separately) if you just disconnect the top radiator hose also. Heat recovery system with heat storage tank, coolant control valve, and heat storage tank pump is probably the hardest and those may need to be all done separately. And I also think that those might be the most likely source of contamination in the system.
     
  17. Fliebly

    Fliebly New Member

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    No I was just checking the other pumps. Then gonna flush everything. Here’s one of the pieces that came out. I’m gonna replace the auxiliary water pump too. I think it burned it up but it isnt throwing a code, but seems weak.
     

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  18. pasadena_commut

    pasadena_commut Senior Member

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    With all the little light colored bits scattered in it that doesn't look like any kind of rubber I have ever seen in a car. You described these as "foam pieces" . Are they squishy? In the picture I don't see any open cells, as one would with most rubber foams at that magnification. It looks like a bit of tar with dirt mixed in. Mixing different types of coolants can cause sludge, but it doesn't look like that picture. Well, at least initially. Perhaps if there isn't too much of it and it is left to bake for an extended period it balls up into those things?
     
  19. dolj

    dolj Senior Member

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    Has it even been topped up with any other coolant other than Toyota SLLC?
     
  20. Fliebly

    Fliebly New Member

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    My mechanic friend next door thinks that is synthetic foam. It feels like synthetic foam. It’s spongy and has pores to capture water. I hope you’re right because I hope something isn’t deteriorating. I’m flushing and replacing my heater core water pump. I want heat that’s what’s most important.
     
    #20 Fliebly, Feb 28, 2020
    Last edited: Feb 28, 2020