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Does this symptom statement seem good enough? Your own ideas are welcome.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by KellyDean, Apr 18, 2023.

  1. ChapmanF

    ChapmanF Senior Member

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    I wish I had a better guess for what they meant by "subtle 'sweating'". It sounds like they were talking about something seen on the engine's exterior, certainly a way that a head gasket can go, but not the way ours usually do. I also kind of wish I'd seen what they saw and could think about whether head gasket even seemed like the right guess for the source.
     
  2. KellyDean

    KellyDean Junior Member

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    Hey there. Yeah, I just thought I'd pop in with an update. I don't have answers for you on exactly what he meant. He mentioned being able to see up there when the car was on the lift and see what he saw with his flashlight.

    It has been a couple of weeks and I drive a lot. More than most. I topped up the coolant today finally as it approached the low mark. It wasn't much at all but I realize anything missing is too much. My complete guess is there is a mild issue that will get worse one day. I also believe that extra stress and heat from those filthy manifold ports, possibly leaking gasket there, made matters worse...

    It's really ashame, sir. Right now, at almost 229k, it's running so well. I'm manually tracking 43-44mpg. I wish a motor running this well didn't have to get taken out by that gasket. I also wish I would have found someone else to put in a new water pump around 180k when the first guy said, "why would you want to replace a water pump that isn't broken!?" The oil has never been cleaner on the dip stick and no longer disappearing which is nice. I have plans to pay down some little loans and then get a newer Prius when I can afford the payments without stress.

    Thanks again for your input for me. All of you. I'll be back with an update mid-Summer. :)
     
  3. KellyDean

    KellyDean Junior Member

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    Greetings! I thought I'd circle back 4 months later to give you an update:

    I'm at 240K now, from 229K back in May. Car is running great after all that work EXCEPT for what is likely gasket related. After all that time looking for the leak and never finding it, people were wondering where the coolant is actually disappearing to.

    Well, I have the answer finally! When the engine is running, it is coming directly out of the coolant reservoir cap tube thing. (can't think of the name) You know, the one that will allow pressure to escape. It spurts out. Not constantly but enough to cause a good drip. The drip is further up than the usual condensation drip from the little hose down there, and if you're on an incline even by a bit, the coolant rolls into the water puddle and looks like nothing is wrong. It was only after I took off the tire and waited for the engine to kick on that I saw where it was coming from and where it wasn't.

    I use about a container of coolant every month now, maybe less. Car never overheats, still no white smoke or freaky oil. The engine rattle is about 20-30% of the time when it kicks on. Still never when it's from a cold start. Oh, how I wish it was just the thermostat. But now that I can hear a swishing sound from behind my dashboard from time to time when it starts up, rattle or not, I think it's still gasket related.

    If it could still be a thermostat, I'd love to know. I know the heater works great but it hasn't been cold here enough to really know. Thank you. I hope you all had a great summer. - Kel
     
    bisco likes this.
  4. Brian1954

    Brian1954 Active Member

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    In your first post, you stated that you replaced the coolant reservoir cap. Did you buy a Toyota OEM cap?

    Where did you buy the Denso engine water pump from, and how much did you pay for it?

    If you have coolant coming out of the coolant reservoir overflow tube that is just underneath the cap, you have an overheating problem. The coolant may not be getting to 120C (248F) which is needed to trigger the high temperature light on the dash, but it is still overheating. I would recommend that you monitor your engine coolant temperature with an OBD2 Bluetooth doggle and an app like Hybrid Assistant or other app. You should not have coolant coming out of the overflow tube.

    One last question: Do you still have the P0171 engine running lean code, or was that fixed when the manifold was removed and cleaned as described in post #14?

    Posted via the PriusChat mobile app.
     
  5. MikeDee

    MikeDee Senior Member

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    #25 MikeDee, Sep 17, 2023
    Last edited: Sep 17, 2023