2012 prius w/240k miles. Im losing anti freeze and when its very low, i loose my heat too, i assume thats to be expected. In addition, when i do run the heater, this serms to be the only time I loose anti freeze. Turn the heater off and all is fine. In fact I took a 10 hour trip in it the other day with no problems, i just didnt use the heater. Also, when i do run the heater, there seems to be smoke coming from the center, left side (drivers side) of the engine compartment, as you are sitting in the drivers seat. Any advice you can offer would be great. Thank you !!!
Sounds like you have a leaking heater core. But, I do not think there is heater valve. There's just a flap the redirects the air around the heater core. You need to do a pressure test and see/hear where it's leaking.
The smoke/steam you are seeing is a useful indicator. Bring the engine up to normal temperature, park in your driveway, turn on the heat, and check everywhere for drips with a flashlight. With any luck, you'll see something you can fix. You did not mention smelling coolant in the passenger compartment, so that's a hopeful sign that a leaky heater core may not be the problem.
Just curious, doubly so with 240K miles: have you ever cleaned the Exhaust Gas Recirculation circuit and Intake Manifold.
Hello Mendel Leisk, Im older and at times forgetful but seems to me someone else recently mentioned the egr valve to me too. To answer your question, I've yet to touch the egr valve. Honestly we live on a fixed income and absolutely love our prius. We have made it to 240k miles performing a minumum of maintenance. Aside from oil changes, tires and brakes, we havent done anything to the car. Wait thats not totally true, we did do the spark plugs, boots and a clock spring to fix a broken horn, at about 220k miles. About a month ago I had the dreaded check hybrid system light come on. At about the same time that happened we had an odd electrical problem occur. When you turned the car off, the outside driving lights would turn off too, as expected, what wasnt expected was after about 3 to 5 minutes later, after turning the car off, the back lights, and only the back lights would turn back on. Not the headlights, only the back lights. Well out of pure fear of draining the cars battery and becoming stranded, I would disconnect the cars battery whenever I parked it to prevent draining the battery. This not only worked like a charm as a temporary fix but the dreaded "check hybrid system" light never came back on, and well the back lights stopped misbehaving and are now operating correctly and I dont disconnect the battery anymore. Talk about Toyota quality, I just love a car that fixes its own problems itself without my having to hire a mechanic. I am preparing to locate a mechanic that i can trust with my prius. The last one who did our plugs was a rip off in my opinion, he charged us 300 to do the plugs, and i supplied the plugs, plus he charged me an xtra hundred bucks to replace the 4 boots on the spark plugs, which i thought was really price gouging considering i can buy the boots for about 5 bucks a piece. Im thinking maybe my hybrid battery may be getting weak, which in turn caused the odd electrical problem I experienced. Of course Im just guessing at this point. I do know I have to fix the exhaust gasket to pass inspection and to get the check engine light off. A mechanic explained to me that the egr is after the exhaust leak, which means the check engine light is pointing to the exhaust leak not the egr valve, but maybe he has it backwards? What do you think? (Sorry for the long reply)
I’ll give more info later, but one thing: you’re way overdue for Exhaust Gas Recirculation and intake manifold cleaning. Best done by 100k. Owners are blowing engines due to this. And Toyota doesn’t want to know.
@Dominic&Leslie again, with 240k it’s likely the coolant loss is due to head gasket failing, so Exhaust Gas Recirculation cleaning too late, though still good to do. A leak-down test can confirm head gasket condition. Anyway, here’s info on dealing with the Exhaust Gas Recirculation: Link
