2011 Prius 281k miles - would you replace the head gasket if you were in my situation?

Not what I would do at 281k miles that is running well (wait! ...I am at 280k!). I would not leave the flawed pistons and rings and I would change the intake for the revised model. A $200 sintered bronze catch can. Plus the head professionally cleaned, inspected with new valve seals. Probably easier to do a rebuilt engine.

But it is what it is, a new head gasket. Hopefully the timing goes together correctly, it is a common problem some mechanics have - partially because of conflicting timing marks. Some timing mistakes result in bent valves. Another common issue is timing chain cover leaks at the tensioner gasket and the block seams.

 

That's great!
What did the inside of the cylinder walls look like? Any scoring?

The timing chain is the easiest I've ever done. Super simple. I don't understand why or how
you could have any trouble with it.

I have just over 2000 miles on mine and no leaks or problems. Still running smooth!

 

I don't know if it's a crappy design bc all I have to go from is the very limited amount of Pri owners that get on this forum.
I stand corrected.
But from what I read on this forum and from personal experience HG failures happen routinely.
I have a friend that had two replaced on Gen 3's.
And this forum (you) recommends EGR cleaning even tho the system has a fault code for when the EGR flow is below spec.
If a forum member actually cleaned the EGR every 50k, as you recommend, what is the record miles for their HG?

Very good!
But is this 'Hats off' to yourself?
What's the history that got you to 281k miles, if that's what we're talking about?
I had one go 240k miles before the HG started showing signs of failing.
It had very low, but measurable oil consumption. (I'm sure yours is measurable)....
And it ran fine when I sold it with Blue Devil in the coolant.

 

i meant the OP’s car. My Prius drink something like half a litre per 1000km. Measurable it is

 

IIRC @ASRDogman was past 300k miles and his head gasket just blew. Not sure when he commenced cleanings; he may chime in with more details.

 

Again, compared to say, a Corolla or an Accord, it seems that the Gen 3 Prius head gasket is what fails routinely.
Is there a way to document this?
Is there data from dealerships or independent shops on what takes out Gen 3's? Probably not.

All I have is anecdotal evidence.
What do you have for your position? ,, and the theory that cleaning the EGR will keep the HG happy and long lived?

I know many people that have run cars way up there in miles!
Me with my 240 k mile Geo Metro, running fine with very low oil consumption. Bought new but was rusting in two at 13 years old.
My 254k mile Honda Element, same ( thanks Mobil 1 !)
2 TDI's in the +300k miles, but other maintenance items for these was a deal breaker for me....

Believe it or not, my Prius bud, that has a fleet of Pri and is a courier, was the guy that put 1,000,000 mile on an Accord.
No major engine work, original suspension. He was featured at the Marysville Honda plant 20 year celebration in that car.
We was given a new Accord on swap (no taxes!), but soon switched to Pri after that.
He's had a Gen 2 Prius at +600k miles, with no head gasket issues, before it was in a collision that totaled it.

 

I’ve yet to hear of a 3rd gen with timely EGR cleaning have a head gasket failure.

The EGR passages in intake manifold tend to clog sequentially, commencing with cylinder one, and the head gasket failures are almost always at the wall between cylinder one and two.

the head gasket failures occur in cars without EGR cleaning, typically 125~200k miles, and belated cleaning of those cars reveals EGR systems with near-total carbon clog.

Toyota touted revised EGR system with the advent of 4th gen, an oddly esoteric subject?

I don’t need exhaustive proof, a reasonable hunch keeps me motivated.

 

In my case cooler and valve were quite clogged but the manifold passages were not. Not even that famous cylinder #1 passage. So certain type of driving, environment, fuel, engine oil etc. is needed to get those passages clogged and do so unevenly.

 

And then there's the question of Brazilian Pri with no EGR system.
Do those HG's last longer?

I'm so tempted to disconnect the EGR connector, or install a thin block off plate at the manifold, and say Ta'Hayl with it.
And I'll try to document the 'enormous' hit to fuel economy.

Will running with no EGR make my HG last a long time?

 

I had a '73 Ford van where the EGR port was plugged. I left it that way. It ran fine and didn't blow a head gasket.

This thread is a counter to clogged EGR systems blowing head gaskets. Certainly the OPs Prius has a clogged EGR system yet he's at 281K miles with a good head gasket.

That old expression "Don't confuse me with the facts, my mind's made up" rings true here.

 

The Brazilian Prius likely are tuned different, milder valve timing and/or cam lift. A properly flowing EGR system allows the engineers to push the limits of efficiency further. They took advantage of that, counted on that?

I’m a little incredulous too; perhaps @koukilights can clarify:

how long have you had the car, does it have original engine, and any history of EGR cleaning?

^ Here he indicates he's had the car since 217K:

2011 barely getting 41mpg | PriusChat

Pots and kettles?

 

You're grasping at straws here.

 

You seem to have a lot invested in this. How about we stick to uncovering facts, preserving the well being of our cars.

 

How about you stop the fearmongering when you don't have the facts to back it up? How many people have attempted cleaning the EGR system on an otherwise good running car and screwed things up or unnecessarily paid $1000 to have a mechanic do this? The fact that these systems clog up is not in dispute, but the correlation with head gasket life is.

 

Egr improve fuel economy some 4-5% in hybrid cars. Less in conventional cars where the engine need to be responsive at all times.

4-5% equals couple deciliters / 1cup per 100km. Not huge but i want it. I had egr blocked for short period when valve was stuck open. Car worked like charm if not better

 

Stuck open and fine, even at idle? I'm wanting stuck shut.

I wonder if the Brazil has their version of EPA mileage numbers? I wonder if they are '4-5%' lower...
I think they go crazy with the ethanol, so that may play into it. So much sugar cane!

I wonder how many hybrids in this country have an EGR system?

 

When valve is stuck open engine rattles like h*ll. Never in my life i’ve heard engine sound so bad and shake so much. First thought was OMG, this car is done. But when you put metal plate between valve and the pipe it runs silky smooth troughout the range. Engine adapt the situation (no egr flow). You’ll have the CEL on of course

 

I get 62mpg going to work right now every day on my 2010 prius with just the EGR unplugged all speed limits below 45mph and stop light to stop light because we hit them all. I've tested with and without EGR and oddly it never amounted to a large enough difference to measure. I hesitate to say it but the egr delete would always get 1-2 more mpg and my EGR system is squeaky clean lol. But we do know the engine reduces the throttle butterfly loss at lower loads under about 2100 rpms when the EGR is functioning. Throttle body percent goes from around 75% to 85% at all times which theoretically makes the engine more efficient. My tank averages are about 57mpg though with 205/70/15 tires.
Also, the head gaskets fail from pinging from incorrect mixtures in the cylinders. Keep the EGR system clean and balanced and you won't delete the head gasket. Keep the egr system unplugged and you won't delete the head gasket. I wish more people would realize the head gasket is fine, its just not made out of indestructium. If you keep pinging and knocking the head gasket in any car for 20,000 miles they will all eventually fail. Especially in a 13:1 expansion ratio engine (atkinsion cycle engine here so compression cycle is a bit lower than actual compression)

 

You are inspiring me to unplug my EGR at 128k miles before HG problems ,,, possibly due to an imbalance in EGR flow to individual cylinders, right?
Case closed, right?

Only now explain why this engine has a Knock Sensor if it doesn't prevent knocking/pinging/detonation?
Isn't it there so the system can adjust mixture/timing to prevent knocking? WTH, over?