Coolant detected in exhaust

For 2017 Prius Plug-In (aka Prius Prime ), probably.

Not sure when the reports started surfacing, would guess around 2019. At some point soon thereafter (hopefully) Toyota cracked down on whoever was manufacturing the Exhaust Heat Recover (plus Catalytic Converter) section of the exhaust, and remedied the coolant leak problem.

 

Yes, but since the engine isn't used as much (unless you never plug it in), there will be less usage of the exchanger so hopefully (I have a 2017 Prime), it will be less frequent.

 

Lol, that was a good one. I'm wondering what the MPG benefit is of this heat exchanger? It's probably only minimally worthwhile in the winter, and if its <1-2% MPG, wonder if it's worth having at all?!?!

 

Good point. It adds complexity/weight, benefit is “slightly” faster warm up, but it sure backfired (excuse the pun) on Gen 4.

Gen 3’s EGR system and low-tension piston rings were similar in intent, and outcomes.

 

I wonder if it's there chiefly for an MPG benefit, or for an emissions benefit? It could also be both....

What's weird is, there's exactly such an exchanger in gen 3, and it judging by (the dearth of) posts about it here, that never became a notorious source of leaks.

Seems more like they out-engineered themselves for gen 3, and then out-cost-reduced themselves for gen 4.

(But then, I also don't know whether the redesign of the part for gen 4 was somehow an inherently less durable design, or they just had a supplier that made them poorly.)

 

There were exhaust recirc leaks in gen3 early production. According to Toyota the Exhaust Recirc system “replaces the coolant heat storage tank” used in gen2 for faster warmups.

 

I haven't seen any of those reports for gen 3, and I've seen multiple threads (and a Toyota service campaign) about them for gen 4. So that's just me saying what I happen to have seen, but that's enough to make me think it's been noticeably more of a problem in gen 4.

Were there any Toyota service campaigns associated with this exchanger in gen 3?

 

Attached is a copy of Toyota instructions for one of the gen3 exhaust recirc coolant leaks I worked on at a shop back then. We also had hatchbacks leak.

 

Interesting. That C0F campaign was about a leaky actuator for the exhaust gas valve. It applied to some 2012 Prii and could be fixed just by replacing the actuator, so the heat exchanger was ok in that case.

Thanks for that; I hadn't seen it.