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

You have some challenging dilemmas. Perhaps a close look at all available resources might be helpful.
1. Other people. Do you have trustworthy real friends or family at either place?
2. Other vehicles. You appear to have significant mechanical experience. Has this allowed you to locate other possible vehicles to buy, use, borrrow?
3. Credit. It appears you don’t have much money in reserve. Do you have access to credit? Like credit cards.
4. What is definitely in this move for you?

There are many people who would pay you to use the automotive skills you have. Don’t overlook this as a resource. Don’t sell yourself short.

To more directly answer your question I would, in your shoes, try hard to get a reliable low mileage vehicle. Although this might be practically impossible. I would not start the job on your car until you have moved. Then I would figure out if I could live without a car. Then I would work hard to find a place to work on your car. Preferably in return for working on someone else’s car. I would regard your present high mileage car as unreliable for practical purposes. Your biggest asset is your skill set. Many many people can’t change their own oil.

Good luck. You bring a lot to the table.

 

How many MILES on the car?
It is no different than any other combustion engine.
You should get the FULL head gasket kit from Toyota. The FULL one
includes the throttle bodly gasket, water pump gasket, and the "O" rings for the
oil filter housing. And get new head gasket bolts.
If you've watched several different video's on replacing the gasket you should be ready.

 

if there is nothing wrong with your head gasket now, a new one isn't going to do anything. Cleaning out the EGR cooler and intake manifold, along with changing out the water pump and coolant should help in preventing the head gasket failure.

 

Dang, that's a new one. Replace a Gen3 HG preventatively.... Before a big moving road trip..... Yikes!
Isn't this asking for trouble?
So much can go wrong. And the possibility of it showing up while on the road is real.....

(what a crappy engine design where some people have to consider doing this.... But I really like the one I have presently!)

In brief, the HG gasket failing will not leave you stranded on the side of the road. It's a slow, easy to spot issue, and you can put snake oil in the coolant to keep it going for a long time.

Here's my one experience: TLDR
I had a Gen3, w/240k miles, show the first signs while climbing the Rockies at high power. I got an 'over heat' light. We were almost at the summit and I pulled over, popped the hood, saw steam coming from the coolant reservoir, started the engine again and let it cool for while and continued on our vaca and never had it show up again. But also I didn't have to power up summits at high power for the rest of that trip.
I remember once I got home it was determined I had exhaust byproducts in the coolant.
I used Blue Devil "HG sealant", which is silica based. There's a procedure.
All was good for almost a year and the next vaca the same issue showed up. (I didn't reduce power climbing to the summit, which may have helped.)
That time it lost a bit of coolant which I topped up and all was well for the remainder of the trip.
I sold it as-is when I got back. It ran fine and didn't do any knocking on start up and may be fine to this day.

On a previous to that Gen3 I had knock at start up once after putzing around a coastal town in cool, very high humidity conditions the night before.
My pet theory is moisture/ice is accumulating in the intake system and settles out overnight in the intake manifold....

Good luck to you, young sir, which ever way you go....

 

IMHO; I wouldn't mess with it. Clean out the intake & EGR cooler and call it a day.

I would save up; line up a rebuilt engine as a backup and pay a shop to do the swap-out. I wouldn't trust just a HG job on an engine with over 100K miles on it. Everything else has that equivalent wear on it; better to drop in a fully rebuilt motor than chance something else breaking.

Just my 2 cents....

 

IMHO, 100k on a modern engine is nothing, barely broke in....
I've had several in the +200k range that did not consume much oil.
My current one is ~125k miles and has very low oil consumption!!
I guess it depends on the previous owner's maintenance routines.

I have a courier friend that has had several in the +500 k mile range and no major issues, other than this dang crappy head gasket design.
But then that's ideal usage, just cruising down the highway. He's had good results with 'Ring Soaks' when the oil consumption creeps up, and now has decided to start doing 5k oil changes.

 

Do not open that open deck engine . It's not friendly internally . With this type of engine you replace the center section reciprocating mass redo your head and then assemble all that That's in the $6,000 plus range for that kind of money I could put three JDM spec engines one after the other in any of the gen 3s that I own and still have a couple bucks left over those three JDM engines will easily outlast the thing you just spent $6,000 plus doing easily The car will be well ragged out quite a bit before I go through the three engines if the chassis even makes it through that a Gen 3 I don't think so A Gen 2 comfortably. But a three the whole car is going to fall apart all around you the interior is going to be trashed all the buttons will be clogged with garbage and it's just not a thing at least not for me these Gen 3s are kind of disposable You just get them all yucky and throw them out because all the cleaning and all of that stuff in the world will not help It will still look old and ugly especially the interior oh my God.

 

Hopefully that Felpro HG will have a normal life span compared to the crappy OEM design!
Good luck on the road trip and hopefully +200k miles into,,, the Future!

Keep us posted!

 

It seems to do just fine, if the EGR system is periodically cleaned, say every 50k.

 

No I wouldn’t. A Tesla can bought for $30,330 as of current time after rebates and state tax rebate incentives, since finances was not stated as limited.

 

Peace of mine is priceless!
Not a hard job, just lots of things to unbolt, unscrew, remove, get out of the way..........
Are you also doing the valve guide seals? And checking the sealing of the valves?
Hopefully they are all sealing and you just need to change the seals.

Take photos.

 

Do we know of any specific features that might make the Fel-Pro a better choice than OEM?

 

No, we don't. Only time will tell.
We do know no matter how much fiddling under the hood you do in the hope of prolonging it, the HG will be the first thing to fail in a high mileage Prius.
Other engine designs can go a very long time without the HG failing.
Me and many others have examples. Us that keep a car running forever...

 

If that fiddling included periodic EGR clean up, I think that “crappy OEM head gasket” will be just fine.

 

At this many miles, I'd look for a rebuilt or low miles used engine. Replacing the head gasket on a worn engine is a bandaid fix.

 

Is there any proof that doing all this work keeps the HG from failing routinely in the +200k range?

No way to know, bc as you know the geeks on this forum are a very tiny amount of Pri owners.
Most probably follow the normal recommendations and no way to know how long a typical HG lasts.

 

But you know the head gasket is crappy.

 

281k miles and no oil burning. Hats off