Engine coolant inside catalytic converter

What Alan just said. I was preparing to post essentially the same. My shortened version -- it could be any minor tweak or improvement, however invisible it may be to the naked eye. Whatever the change, though, we can be pretty sure it reflects some important improvement, however the need may have been discovered. I have no idea of the magnitude, but there must be substantial costs to making such changes, through the hard "pipeline" of parts as well as the ancillary stuff like the cataloging and so forth. From this, I surmise that Toyota does not make such changes "willy nilly," on a whim or however else one might describe it.

 

Loosing Coolant 2017 Hybrid Prius 58k
Western Toyota no leak buy antifreeze to top it up .

Two weeks later white smoke back Toyota Stirling no income after investigation they found the leak .

Hi Mr Kennedy - the exhaust is required to be replaced due to the heat exchanger internal failure. This will be covered by Toyota warranty. We are aiming for it to be ready 17.30 Wednesday. Thank you Stirling Toyota.

 

John Kelly is so knowledgeable. He's the guru!

 

my 2016 Prius Two Exhaust pipe replaced using T-SB-0135-19 at 46K.
now at 51K, coolant leak and engine over heat and they are saying engine has to be replaced.
codes
P00B111, P011511, P148F00 AND P319000

 

Did your Check Engine light came on?
If yes what codes.

My 2016 Prius (51K) did not emit any white smoke, but it is sounding like Engine gone bad now (it started with low coolant symptom)

 

I just sent my 2017 Prius for service. I had the same problem and it is indeed caused by a failing heat exchanger. Covered under emissions warranty. The car is still in the garage right now, I think they are bypassing the system so that I won't loose coolant until they get the ordered new part.

 

Check out this thread that I started. It got no replies.

 

2018 Toyota Prius ==> This exact thing happened to me lately and I thought the coolant was leaking in the engine since there was no leak. Honestly, when the mechanic told me that the converter was causing the problem I couldn’t believe it. He said he kind of bypassed the exchanger part. But also mentioned that I have to get it fixed. $1300 for the part. I am
Still driving the car. It’s been 2 days. Do you guys think I will be damaging the engine somehow driving it?

 

I'd get some better information on how the mechanic performed the coolant bypass around the catalytic converter. There are at least a couple of ways to do it. One is at the converter itself and another is under the hood.

I don't believe there's any harm to doing it, but you might notice your car takes longer to warm the cabin because the coolant is not passing through the hot exhaust gases in the converter.

As long as your engine coolant tank stays full and you don't get any engine overheat lights, you are not damaging anything.

 

Just editorial: it is-fact the exhaust heat recovery system being bypassed, isn't it?

 

The Gen 3 does not often have the leaking exhaust preheater issue.
It developed evidently with the poor design in the Gen 4.

Most likely, the flaw resulted from the aging of the metal at a stress point that opened a crack after numerous heating and cooling cycles.

With those issues, Toyota eliminated the preheater with the Gen 5.

 

I'm I had to pay for the part I'd just bypass it and never look back

 

Others have had the part replaced with the updated part under the emissions warranty, like stated earlier in the thread.
If it was the same without the heat exchanger,Toyota wouldn’t have put one in. It probably isn’t as simple as it warms up slower.

 

I disagree. Sometimes engineers can be too smart for their own britches. In other words, by trying to heat the cabin quicker, they introduced a failure point that potentially becomes much more serious (coolant loss with subtle symptoms until too late --> engine overheat with severe damage) than the issue they are trying to improve.

 

My wife has a 2018 Touring with approx 90K. Noticed no heat when we had our first cold snap in late october. checked coolant and it was really low. Topped it up and kept an eye on it. Sure enough, it kept losing coolant. Took it to the dealership TWICE; the first time,(November 23) the only thing that they could come up with after having it for 5 HOURS was to swap out the reservoir cap, which I did. $200 + $60 for cap. Went home relieved but skeptical.
Three weeks later, coolant level drops again. Keep topping it up. Brought it back Dec 23. ANOTHER 6 HOURS AND $180 This time they ruled out heater core and head gasket . Here's his report:
" Check heater core,throttle body, egr,exhaust for leak. Nothing found.
check engine cylinders for leak,nothing found.
Ran through everything in the engine coolant system and could find no leaks. Nothing to fix if I can't find anything wrong"

I mentioned the TSB but they were somewhat dismissive. There's never been an engine light indicating any problem. What should I do?

 

1. Explain issue to Toyota Corporate about dealer not adhering to TSB.
2. Change dealer.

 

Hello Megatron1337, I have the same problem on my 2018 Gen4 with 60k miles. Lost heat a couple weeks ago. Dealer replaced the thermostat and got heat again. But when I accelerated to get to highway speed, I noticed a cloud behind the car. Dealer looked at the car again and found the leak in the catalytic converter. Car is still in the shop, waiting on parts. I am told there aren't any cats to be had in the US right now.

 

Let us know how long that wait is when you do, I recently did the bypass under the car and have burned off the coolant in exhaust so no more cloud behind the car and have not lost anymore coolant.

 

Make sure to keep the reservoir topped off and look in rear view mirror when going uphill and see if you have the white smoke/vapor behind your car. That seems to be tell tale sign that the heat exchanger is the issue

 

Hello, there are different bypass methods for a broken EHR. When there is no coolant flow around the ehr thermostat, the exhaust flap is always routing the exhaust gas through the EHR, isn't it?
No coolant flow around the thermostat > then the temperature in the thermostat is low and the exhaust gas is routed through the EHR.
Is it a good decision to drive all the time with the exhaust gas routed through the EHR?