Any Gen 4 Owners Out There With Blown Head Gasket ??

Ha! Although I’m happy my vehicle is now fixed, it imitated James Bond doing a smokescreen if I used full throttle!

 

Early models? All the way through 2019 it shows. Dang.

 

If mine goes out, I'm simply going to bypass it and move on. I'm almost to 100K, and I'm assuming it's fine for now. Once out of warranty, I don't think I'll fork out the almost $1K for the new part minus labor.

 

So, if I understand it correctly, the exhaust heating the coolant was just for more effective initial heating of the engine for top-level fuel savings.

I have a feeling that I don't even need that complexity for a south Florida vehicle.

 

In a word, yes. It’s for people who can’t wait longer for heat as well. It’s a neat idea when it works, but in the end, may not be worth the convenience or gas savings, especially since some models don’t even have it.

 

The puzzler is what they did to it in Gen 4 to mess it up. They already had it in all six years of Gen 3 and I never heard of leaks into the exhaust being a thing then.

 

Maybe need to change the thread title:

Any Gen 4 Owners Out There With Blown Head Gasket ? [crickets........]

 

I have a theory that the exhaust coming from the cat is hotter than the exhaust going into the cat and perhaps the engineers didn't take that into consideration when they relocated it in the 4th gen. I don't know if it's leaking welds or somewhere else, but either seems possible. It would be nice to see an actual failed unit, but I hope it won't be mine.

 

Yeah, I've wondered about that, too.
Besides jerrymildred's reasonable guess of increased temperature, another one might be that they decided to lighten it and make it more efficient by thinning the tubing walls---leading to fatigue or corrosion failures.

 

Hmm, Jerry's guess puzzled me too, and I forgot to post about it.

Did anything change Gen 3 to Gen 4 affecting the temperature of exhaust entering the EHRS? The EHRS is the leak we're talking about here, right?

 

UPDATE:

Just got a call back from my mechanic. After sending him the video and TSB provided on this thread he went through the diagnostics and concluded that my heat exchanger on my 2016 was also bad and it wasn't the head gasket afterall. So you guys saved me a TON of money. They are still pricing out the parts and labor to do the heat exchanger. But it can't be as much as a head gasket. And I'm very thankful my car wasn't ripped apart unnecessarily.

I guess that is one downside of going to a non Toyota mechanic. My local shop is very good usually. They have done good work on my wife's Highlander and my daughter's Kia Soul. But they definitely missed this one. Could maybe have been a little bit my fault because I walked into the shop saying that I probably have a blown head gasket.

Anyway....thanks guys.

 

Glad you're on the right track now. Hope it isn't too expensive. But even a Toyota mechanic could miss that one if he or she isn't alert since these are still pretty uncommon. They will probably get more common as the miles accumulate.

 

Not sure but have to ask: has Toyota done a warranty extension on this? You're not eligible?

 

I haven't looked into that. Car was bought Sept 2016 so going on 6 years old and has about 90,000 miles. I'm not dealing with Toyota but an independent shop.

Today I talked to them again and they told me that the heat exchanger is on national backorder with no indication of when the part will become available and no approved aftermarket alternative. I asked if they could bypass it and the clerk checked with the mechanic who said no but I don't know if that was a "no, you will ruin your car if you do that" or "no, that isn't something that Toyota authorizes so we can't do that" They did say it comes up as a $2100 repair job parts, labor, and tax once they get the parts in which is who knows when.

I'm willing and ready to try to bypass it myself. I'm reasonably handy and have done my share of working on cars and have a pretty well equipped home shop. I just need to find legitimate instructions on how to go about it. I guess I'll put up a new post on that topic and see if anyone has any advice.

 

In the UK we have Toyota Relax warranty which provided you service your car in their dealer network you get warranty up to 10 years. We used to have 5 years, but then they introduce this great warranty package.

"Up to 10 years (100,000 mile) Toyota warranty - With Toyota Relax
Every new and used Toyota, is eligible to be covered by up to 10 years’ manufacturer warranty through Toyota Relax. This is provided through an initial 3 years manufacturer warranty from the vehicle’s registration date that can be extended with regular servicing at a Toyota dealer.

12 months warranty is included with every Toyota Service, up to 100,000 miles or 10 years, whichever comes first, giving you a chance to relax in the knowledge that you and your vehicle are in safe hands. *Terms and conditions apply.

This also includes a 15 year warranty on the Hybrid battery too.

Do you have that in the US?

 

Not that I'm aware of. It was never offered to me anyway.

 

Not that I'm aware of. It was never offered to me anyway.

 

Not that I'm aware of. It was never offered to me anyway.

 

Hi! I’m new to the forum. My 2016 Prius 3 with 135,000 started leaking coolant around 7 months after I had the coolant flushed as a normal PM. I brought it into dealer and they reported that I will need the head gasket replaced (they specifically mentioned that it would not need a new engine, to my surprise from what I’ve read on this forum). I stopped driving it once I confirmed that the coolant was leaking. There was one time that the overheating light came on - we pulled over immediately and added coolant. The dealer scoped the cylinders and found them to be clean, and found signs of leaking at the exhaust. Also they found markings on the pistons, which they say indicates that they are leaking and burning coolant. See attached photos from the report. Do you think it is possible that I also have a heat exchanger failure rather than head gasket?

 

Highly probable, just considering the stats: there is a problem with exhaust heat recovery system leaking coolant on 4th gen, and I don't recall ONE blown head gasket reported here. This (page 2) post has more info:

Any Gen 4 Owners Out There With Blown Head Gasket ?? | Page 2 | PriusChat

Print out the TSB and show to the knuckleheads at the dealership?

One simple way to test is to DIY bypass the exhaust heat recovery, see if the coolant level stabilizes. Dealerships are refusing to do this, even when replacement exhaust components are not available, saying they're not allowed to disable pollution control equipment. Which leaves you with a brick.