Self proclaimed expert explains why Prius Headgasket Failures are normal, early, and inevitable

Aloha Airlines had a 737 roof rip right open in the 90s. All the island hopping and short cycles stressed it more then the engineers originally planned for.

 

That sounds like the story I had read about; I just hadn't recalled the details.

 

That a good time to clean..... and now you might want to change the trani fluid....

 

What about its electrical and heat-transfer properties? It needs to not mess up those electrical components its supposed to be cooling -- and it needs to transfer the heat efficiently.

 

Haven't done a chemical analysis in my lab..... I use it in the engine and trani..... plus the v has trani cooling..... it's just oil from toyota...nothing magic. You could put 3 in 1 oil in there and it wouldn't hurt it. Conductivity means nothing.... I've had a whine and glitter in my trani for 50,000 miles.

 

I thought about the Aluminum stress. That was outside the plane in contact with air and the elements. See YouTube videos about the Comet. That's an interesting story...

But here we have Aluminum mated to Aluminum. The same alloy is what I'm proposing. They would expand and contract at the same rates... It was just a thought. The one time use bolts I've dealt with are torqued to yield as I understand. Not sure how that ties in as well...

moto g(7) power ?

 

The AL bolt would have to be thicker for same strength as steel. Plus I have worked on some BMWs where the AL bolts just break from fatigue. As far as steel bolts causing H/G failure?- I say hogwash. Steel fasteners have been in use for all AL head & block engines for decades. There are a few designs that have problems (cough - Subaru) but most are fine.

Posted via the PriusChat mobile app.

 

Did that and coolant when I bought the car last year with 42k. Hopefully good for a while.

 

I agree with those that think it's more than one thing contributing to the problem.
Toyota obviously thought it needed to change the EGR and head gasket for a reason. Otherwise they would have left them be. Their no different than any other company that is focused on profits.
Many first generation alum head on iron blocks had head gasket issues. And that was at a time when if you got 150k miles total, you were lucky. So this is not a one off new problem.
I even blew a HG on a venerable Ford 300 with only 123k. And those WERE considered one of the best motors ever made at the time.
Heat fluctuations can definitely add to the equation. Heat cycling can lead to failure in most anything.

 

I agree. The guy makes a lot of sense. I cleaned the IM and changed the coolant at 70,000 and 113,000 miles. Cleaned the entire EGR at 113,000 miles. Losing coolant now at 125,000 miles.

complete BS indeed in your post. in my city commute, the ICE is on only 50% of the time (measured by a vibration engine hour gauge).

shrug, it depends on your ambient temps and if you use cabin heat. besides, you only see the coolant temp. the cylinder liners temp is way more variable, especially with high engine RPM and load.

 

My commute, ice is on 95% of the time.

 

your commute is clearly different from mine. understandable. someone else commute (stuck in traffic) may be worse than mine, where the traffic is not bad, only stopped on red lights. hence the sam spade 2's claim that ICE has to be on most of the time is absurd.

 

My ICE is on at least 98% of the time...... his commute must be down to his mailbox and back.....
I drive at least 150 miles a day on the Interstate and the 1.8 is on most of the time.....

 

i find your remark insulting. FYI, it's 10-12 miles one way, suburban/city commute with some stops in between. how hard it's to understand that not everyone drives hwy only?

 

You are right. I need to clarify what I meant to say.
With a conventional hybrid, the engine is on most of the time THAT THE CAR IS MOVING.

Now let's see what kind of an insult you can come up with for that statement.

 

I didn't mean that the Enterprise should be hauling garbage.

 

Hi Frodoz737 would you care to share your recommended maintenance schedule. Do you just follow the Toyota recommended service?

 

I shouldn't even post this because we all know any maintenance (especially oil) is alway hotly argued in PC.

Oil/Filter first at 200-500 miles then 5K...with rest of filters. Tranny first at 500 miles then 5K...then every 15K. Brake clean and fluid first at 5K then every 10K. Wheel assys balanced and rotated every 5k. Plugs changed at 100K. Check tire press, fluids, lights and general walk around every fill-up.

Respects, but for those that just gas-n-go...I've already heard and seen it all before...so you just do what you want with your's.

 

It is nothing special to change and improve (any component or construction) design after 4-5years. Many manufacturers play a lot with EGR designs and try to make most of it in terms of emissions, fuel consumption, noise, and try to balance them with reliability. But it’s a very tricky sport. Here diesels are very popular and oh boy how much EGR trouble and stuff going on. Volvo for instance introduced revised EGR in their VEA diesels and they had to modify components several times before the CEL’s stopped blinking. Some customers got CEL already when driving home from service with brand new EGR installed and so forth.. They simply had pushed it too far in an attempt to optimize emissions. I recall EGR had key role in VW emission scandal too. They originally tried to cut down diesel engine sound (because in U.S. People don’t like it and i like it neither) which lead to other challenges and rest is history. I’ve seen intake manifold of a diesel Toyota that was so clogged there was just 2cm hole left. Car had starved on the side of road

Yet, i’ve had no issues with any EGR be it diesel or gasoline. Knock on wood. I was told my Volvo EGR shall get clogged at 200kkm but it now has 235kkm and no issues. Hardly consume any oil. Always prewarmed in winter which is perhaps the most important thing with diesels.

 

i’ve decided my side: it’s not egr carbon build up

From where i am coming from people learn egr clogging, egr cleaning, manifold cleaning, egr delete at kindergarden already That’s because of diesels and their popularity here and because people drive crazy mileages with their cars (there are few diesel Volvo or Benz with 500kkm on the clock in every block). Yet, first time i ever heard HG going because of egr, was when i joined the forum. I checked local rfq database and found just few Prius HG job quotes but on the otherhand Prius is rare here. Still, when adjusted to sales numbers, the problem seem rare. And those rfq’s may be related to ”normal” HG jobs like people messing up with antifreeze or fluid leaking out due to collision or something.

i may be all wrong and maybe diesel comparison is not applicaple. Amount of air in diesels is much higher etc. But i have another gasoline car (Kia) with egr and it has 250kkm on the clock and egr&IM never cleaned (or even checked). My nephew is experienced professional mechanic and his opinion was also that this ”egr connection is a long shot”. Like me he was also thinking climate reasons and the way Prius warms up (=quickly) and that perhaps even Toyota cannot make this set up last decades and 500kkm.

Truth is out there. Hope we know someday