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.

 

identical problem now for me also in UK - TSB attached from November 2020 shows it's known and repairable (from dealership!) ... but dealership says not warranty despite them doing annual servicing; quote £1690 to replace pipes!! (2016 Prius 78k miles) AND can't do for about 3 weeks. DID get complementary 5l coolant though!! Any UK successes to boost my complaint to HQ please?

 

The Heat Recirc system simply speeds up engine warmup in the first few minutes. At cold start exhaust gasses are rerouted inside the unit to maximize heat exchange to the coolant. Soon after the exhaust is returned to a normal straight through flow.

I would consider a coolant flow bypass at least to get the car on the road.
Coolant detected in exhaust | Page 4 | PriusChat
However I would do it at the heat exchanger.

 

Did they say why it’s not gratis?

 

"Exhausts are not covered by warranty"; but progress after escalating to dealership CEO and Toyota UK CEO; watch this space!

 

Your correct, but if the issues is related/effecting emissions control of the car - that usually places it under warranty status. The exhaust gas heat exchanger is part of the emissions systems designed to meet your country's emissions standard. Don't know what your emissions laws on your side of the pond, but I believe ours is 8 years or 100K miles - they vary a bit from state to state......

Hope this helps..

 

If Toyota uses an “it’s not covered” argument, with an expensive part that’s regularly failing due to a manufacturing defect, that’s welching.

really sounds like their plan, considering the ongoing short-supply of replacements.