I have been needing to put in about a quart of coolant every 3 days into the bottle I can see white smoke from the tail pipe But the car drives fine. No misfire. No check engine light A friend said it is a head gasket but I don't think it is as i never feel any shaking from the engine. Anyone losing coolant from the gen 4 prius? Car is a 2021 AWD
I just bought a '19 Gen 4, so I've been doing a bit of research. There was a problem with the EGR coolant getting into the exhaust system directly in the Catalytic Converter area. I think there was a TSB or recall on this problem. You may qualify! Good luck!
It is not the EGR system but the exhaust heat recovery system (EHRS). Coolant is leaking from the heat exchanger into the exhaust system just in front of the catalytic converter. Very common problem on the Gen 4 Prius. Do a search in this forum and you find a lot of information. This should be covered by the Toyota warranty. @andy song , Take the car into your local dealership to get it fixed under warranty.
That would be covered under the federal emissions warranty 8yrs or 100K miles or you may be able to talk the dealership into replacing it for free, reference the TSB. I don't believe the 2021 model year was covered under that - but it doesn't hurt to ask. If they refuse to cover it for free; just by-pass/loop the hose at the heat recovery unit, behind the CAT. There's a few YouTube videos and multiple threads on this forum about this. Search 'exhaust gas heat recovery' Hope this helps.....
No, just new to a Gen4. Isn't there something about EGR being taken post CAT? I've had mine for exactly 2 weeks now and loving it! Still learning the systems and their names.... It's a '19 ECO with only 235k miles on it. So I got it for a song! The Champ!! Next I'm buying a Comma for it. That was the driving force to give up on Gen3's. That and head gaskets. Once is enough..... But the quietness and improved fuel economy are added treats ! I cleaned the battery fan filter, for the first time from the looks of it, but it was easy and satisfying! And today the engine oil/filter and transaxle ATF. Mobil 1 all the way! I won't argue about using WS, again... I like premium lubes !! And soon both air filters will arrive. I'll test the engine coolant and then, relax and drive the Hay'L out of it. while I wait for the Comma to arrive. Are there threads here about setting up the Comma? Updating my signature soon. How about that for jacking a thread????
Leaking coolant into the Exhaust Heat Recirc system at a high rate needs repair or bypass asap. Otherwise you risk a badly overheated engine and then a head gasket.
thanks @rjparker - I guess my memory isn't that bad from old age. I don't believe Wisconsin is a CARB state.
For what it's worth, I'm pretty sure that heat exchanger is just behind both catalytic converters. In a gen 4, the first catalytic converter is built right into the exhaust manifold. The second converter is the first bulge in the exhaust pipe. The next bulge is the EHRS heat exchanger, and there's probably a resonator/submuffler bulge after that.
Shouldn't you see if the car qualifies for a free emission systems repair at a dealership first? There is a lot on info about this system failing.
Just look for two black rubber hoses going into one of the exhaust pipe budges; that's the lines you'll need to loop.
After you verify Toyota won't repair it free (which could get you a new assembly), I would have any shop with a lift immediately do a below vehicle bypass. Option 1 Bypass under the vehicle Option 2 A no lift, no parts required driveway bypass requiring more time. Bypass in Engine Compartment requires Wiper Assembly and Cowl Removal Long term a bypassed heat recirc/exchanger should have the internal actuator forced open. However this is not an immediate requirement as an exhaust flow still exists and normally exhaust pressure alone will open the straight through path.
Thank you, ChapmanF, for correcting what I wrote in post #3.. I am not very familiar with a Gen 4 Prius and normally do not make posts in the Gen 4 forum.
