4th gen head gaskets are starting to show up in large numbers...

Not all hybrids- Toyota's own 1.5L 1NZ-FXE engine is proof of that, before you even look at other brands.

But maybe all the 1.8L ones....

 

gen 2 seemed to hold up well, but are gen 4 like gen 3, or is it happening at higher miles?

 

tough to tell how many and the mileage from that short clip. there have been reports here, but a lot seem to be from overheating due to the coolant leak at the heat exchanger

 

There is a big difference in cold to warm in San Jose to somewhere like Edmonton in the winter too. I know what he is saying but so do the engine engineers. Like 100 years ago or more they knew about expansion and contraction in an engine. Engines with cast iron block and aluminum heads, all should be in the junk yard. But are they, no.
A guy says large numbers showing up, like what are those numbers and how many cars were made? This is how rumors get going. It’s so easy to fall into the rumor trap and think your car is next. I’ve been through it on several cars. Nothing bad ever happened that was supposed to on any.

 

it doesn't happen until it happens to you. hopefully never, but on my 12 with 30k on the engine, something's happening

 

is there an engine code or codes that go along with this?

 

Op has 300,000 miles, is that really a failure?

 

I'd call it "worn out" or "end of serviceable life,"

 

i would die before i reach 300k friving only 10k yr on avg

 

You’re not going to get a code before the head gasket blows, so either keep a close eye on the coolant, or make a preemptive strike by installing the repair loop

 

Too, Gasket Masters is not exactly Moses with tablets...

 

Just found this thread only because a friend's '17 Prius @ 205k miles has the infamous Head Gasket failure.
He was told by a local dealership that, "It's $4800. $5800 with pistons and rings."
He said he has had that dealer do all the scheduled maintenance since buying the car there used with 35k miles on it.
Still,, a few days ago his Prius started 'shaking and has a check engine light'....

I see no reason to call a perfectly fine car with 300k miles on it "at end of life".... Why?
Just because this particular engine has a pisspoor Head - Head Gasket - Block design? Which is repariable...

Another Prius friend has +200k miles on a repaired head gasket, on his Gen2, only that shop used the Felpro head gasket.

Both these guys are couriers and rack up crazy miles on their Prii.

We'll see if they got it better with the Gen5's... Someday in the future.