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.

 

I have the same problem is there a youtube video that shows how to do the bypass? I'm not sure what to search for.

 

Mark, your covered or just over the end of coverage. Pull a copy or give your dealership the TSB # and ask for a good-will replacement, because of a KNOWN manufacturers defect. If they won't budge, go to another dealership and try again - if that doesn't work; Call Toyota corporate directly. Emission control devices are Federally and state regulated; if UT is a CARB state - It is under warranty. States that follow CARB regulations warranties are a lot tougher than the minimum federal regulations. Check your state DMV laws.

Hope this helps......

PS. use the search function; there's multiple threads covering bypassing the heat exchanger.

 

See link in post 91 above

 

Thanks to everyone who has helped with this conversation. I have a 2018 Prius with 50K miles, and noticed my coolant disappearing in the reservoir about a month ago. What tipped me off was hearing liquid gurgle sounds while I was driving my car. Then I noticed the cabin heater wasn't working. I checked the coolant, it was low, so topped it off. Heater started working again with no issues. About a week later, I heard the gurgling noises again and the heater wasn't working. Coolant in the reservoir was low again, so topped it back off. Checked for coolant leaks along with two friends with mechanics backgrounds, and we couldn't find anything. Finally came across this thread and thought it may be the issue. Noticed a sweet smell coming from the exhaust one day when I was looking for coolant leaks, so that really made me think it was the exhaust heat exchanger. I performed the bypass in the engine compartment in front of the firewall about two weeks ago, and coolant level in the reservoir has been fine since. I'll keep checking it for the next few weeks just to make sure, but I think it's "fixed".

I called two dealerships mentioning the TSB. The first dealership didn't want to have anything to do with me. They put me on hold for a minute, and came back and told me my car wouldn't be covered by any type of warranty. I didn't put up much of a fight at the moment. Called another dealership, and I really couldn't get a straight answer out of them as to whether it would be covered by a warranty. I explained all of the issues I was having. They told me they would have to do their own diagnostics to prove the problem, which I guess I understand. My concern is they do the diagnostics and come back and tell me they can't find anything. If this seems to be such a widespread problem, I don't understand why the dealerships are being so difficult and acting like they never heard of it. I have no idea how they get compensated from Toyota for this sort of thing. I suppose if it was a safety issue, it would get fixed with much less hassle.

I'll just keep driving with the bypass fix for now. It may be coincidence, but I feel like my MPG has dropped. If part of this heating loop is to help warm up the engine faster at initial start up, I suppose MPG could drop slightly if this loop is removed from the system. Cold engines are less efficient than warm engines, so maybe the slight MPG drop makes sense.

Now onto another thread to try and figure out how to fix my interior dome lights. Not sure if I'm using the correct terminology. Both interior ceiling lights (possibly map light and dome light???) do not turn on when the doors are open. Yes, they are both in the correct setting to turn on when doors are open. And yes, the bulbs work just fine, as I can turn them on manually. But like I said, that's a subject for another thread.

This is my first Toyota, and I'm not impressed.

 

Calling the dealer is the worse thing to do. First you are likely to get an operator in the service dept whose job is to setup appointments and give out routine pricing but knows nothing about problems.

If you do get passed to a service advisor, realize they are not mechanics, never have been and are not trained in mechanical work. They are commissioned salesmen that sell service and diagnostics instead of cars. If you are calling in asking for advice they don’t have it or don’t want to give it free.

They make money having a mechanic diagnose your issue which is sometimes worth the $150-$200 rather than shotgunning the issue yourself, especially on a hybrid.

Going down there can sometimes get you free advice depending on the advisor. Sometimes the parts guy is helpful.

Once you have a diagnosis from the dealer THEN having the tsb in hand can do it. Realize the dealer has to work for less when Toyota Corp is paying. Plus no markup on parts with Corp paying. So a sleazy dealer makes more by far if you pay for it.

With a diagnosis and tsb in hand you can call Toyota Corp for relief. If you are right they will force the dealer if necessary. You will get a rental car. Nothing will be hacked or bypassed; it will be repaired w the new parts. The diagnosis price will be free or refunded. It’s not Toyota, it’s the dealer management. Corp is on your side with a dealer diagnosis.

By the way warming up fast is about emissions not mpg. It takes less than 5 minutes to warm up. A repair that disconnected the 12v requires the fuel trims to be learned. Otherwise it’s hyper vigilance on your part over a short period skewing perceived mpg.