Is Head Gasket failure common in Gen 3?

I get a full reading on my Gen2 Prius dip stick at 3.5 quarts... People who's opinion I value on here say Prius holds 3.8 quarts. The one time I added too much oil my MPG went down into the upper 30's. When I worked at an autoshop in high school in the mid 80's we added 5 quarts of oil no matter what kind of car it was...

Symptoms of too much oil in the crankcase cause fouling/failure of the catalytic converter as the most expensive potential damage. Fouling of downstream O2 sensor is also possible and my question was specifically about PCV valve also being damaged by overfill... Clearly, you're not the one to answer that question...

 

Not exactly. It takes more oil to fill than two of my three previous vehicles. (My other one took more to fill, but also had a much larger engine.). Of course, people can still overfill it. Whether that is a significant factor in some Prii becoming serious oil guzzlers is unknown.

 

My comments, the previous time I quoted you, was a long ways from courteous. I should read more carefully, and if not understanding: asked for clarifcation, not disparage. I'm sorry.

Third gen spec is 4.2 liters (4.4 quarts), for oil and filter change. Using a graduated pitcher, I've found adding that amount will put it spot on the top mark of the dipstick. I've not overfilled ours, ever, and yet found a real swimming pool at the bottom of the intake manifold, almost 1/4" deep.

An oil catch can helps a lot with that: I checked ours today, about 2 year post OCC install, that intake manifold zone is now just "oily".

 

I have a 2010 Generation 3 with 198,000. Recently the check engine light came on with cylinder 1 misfire. I brought it into local mechanic who replaced coils 1 and 2 and changed out spark plugs. Got car back with same problem. Figured it had to be EGR or something just as expensive so decided to let it sit. A week later I ended up checking dipstick after a quick drive around neighborhood and noticed oil looked like emulsion. Also noticed red temp indicator flashed on and off at end of short drive. I topped up radiator fill tank and took another drive with the intermittent engine shake and check engine light. Next day the radiator fill tank was down. Eureka! Must be coolant leak in head gasket. Read reviews on Amazon for a product called Bar’s Leak Head Gasket Sealer. Bought carbon fiber formula and followed directions. Bottle was 38 ounces so I used half. Took on 15 minute drive and then let engine cool down. Next day (today) I went for a half hour cruise without any check engine light or engine shake. Reservoir for coolant stayed filled. This stuff works and no significant difference in heater output. I don’t see how a clogged EGR passage can blow the head gasket either; especially when not throwing EGR codes. Don’t know how long the fix will last but I like it so far!

 

Along with the head gasket you'll need to replace, shorty, you'll be doing the radiator and heater core.
That stuff clogs up ever little passage.
I believe someone used white vinegar and water to clean out the radiator/heater core.
More than likely the egr cooler is clogged.
ANY stop leak, is only temporary.

 

Yes, I used Distilled White Vinegar and Distilled water 50% -50% as recommended by @Mendel Leisk
to clean the cooling passages.



A couple of buckets and a pond pump

 

I have a 2019 Prius (latest version) a LE model. Mileage 198k. Regular service. The problem with the EGR no longer exists because the EGR takes gas after the cat - soot is no longer there. No problem with oil consumption - good news. The problem with the head gasket remains. I ordered the gasket set. it is naive to expect some kind of change. The engine is the same, no mechanical changes.

 

The head is different, at least how things hook up to it are. And there are some type of plastic sleeves around the cylinders I believe.
And I believe the pistons and rings are different. The blocks may be similar though. As it bolts right
in a Gen3 compartment with no modification and you can use the Gen3 head on it. At least not from what I've read on Prius Chat and other
sites.
So they are not the "same", similar, but not the same.
Better? Well, that's the question.

Did you take your egr cooler out and look through it? What about the intake manifold? I know that's
different than the Gen3. Were the ports clear?

 

What symptoms did you have?

 

Just to confirm, this is a report of a head gasket failure in a 2019 with 198k miles?

A problem with speaking of "the" problem with the EGR is that even in Gen 3 the actual nature and strength of connection between the EGR and head gasket failures has been widely speculated on but still far from pinned down. There are some proposed mechanisms that might be plausible, so it's not all out of left field; the only trouble is that its strongest advocates seem to think that forming a plausible hypothesis means you're done rather than that you've found a place to start. (Or even better if you've thrown up half a dozen different hypotheses with no effort to winnow them down.)

The Gen 4 did change to catalyzed EGR. There are auto engineering journal articles about that; it was an active topic of research during the Gen 3 years, having to do with the way the post-catalyst chemistry of the exhaust gases would alter the effects on combustion in the cylinders. Shoehorning that change into a "they changed it because soot because head gaskets" narrative seems to be done at some violence to the actual story.

 

Just editorial: the quoted portion has typo?

 

I don't know; it might get a red squiggly if I were using a grammar checker older than because noun, but I'm not. This is the internet, after all.

 

The symptoms are the same plus an coolant in the oil. Ignition misfires, noise. I checked with a camera on a hot engine inside the cylinders, i can see how fluid flows through the gasket. no doubt about it.
Egr cooler clean same like exhaust tail pipe. I had other Priuses before, the exhaust pipe after 100k was always black.
Yesterday original head gasket was arrived. Minimal changes in cooling holes so I ordered on the Amazon FEL-PRO 26515 PT I think it is better done. I'll take a photo of the new OEM gasket later
PS English is not my native language. i don't write well , I apologize

 

So the EGR Cooler was clear?
I've not been to the Gen4 Chat so I don't know about how the head gasket is fairing...
I'm sure someone has. Likely not as often?

 

Correct, EGR very clean. I didn’t immediately realize that this is a discussion of the 3 Gen. I got here through google searching about the problems with the head gasket. Time to read another forum Prius 4 Thanks

 

It seems the EGR dirtiness and chronic head gasket failure relationship on the Gen 3's has never been proven.
Just speculated about...

And now the Gen 4 head gasket fails around the same time.
I bailed on my 2011 Gen 3 when Blue Devil only worked for a while on a leaking head gasket, at 234k miles.

I have a courier friend that installed this FEL-Pro head gasket on his high mileage Gen 3.
He has hopes for it lasting longer, but only has hopes... time will tell.

He purposely bought a Gen 2 to add to his fleet of 3 Prii because he trusts the Gen 2 engine to go really high miles and didn't want to spend a lot on a used Gen 4 only to be doing this work at ~200 k mi. intervals.

Head Gasket = Weak Link on Gen 3's and Gen 4's????

 

Blue Devil sealant has great reviews also. It worked on mine in the flat lands.
But when I took it back to the Rockies where you are using high power for extended climbs the leakage returned.
Good luck with Bottled Repairs for this chronic/poor design of a head gasket.

 

The worst idea is putting those crap in cooling system. Heater core, radiator, and all passages will be clogged and won't fix the head gasket.

 

NONE of that crap works. It's at best "good enough to get me home" type of pretend fix.

 

If you never plan to keep it, why bothered. Heater core replacement cost more than head gasket if you find a daring mechanics doing jead gasket