Head Gasket Replacement?

Hello all, I and two different mechanics have come to the conclusion that my misfire on startup(described in my last post) is the result of a head gasket failure or a cracked head. It is a 2005 4runner Sr5 v6 4wd with 117000 miles. Currently down to three options. One, I could have it fixed at the mechanic. I’ve been quoted between 4000 and 5000 dollars by multiple mechanics to do the replacement, with some saying they wouldn’t even do it, and every one of them suggested replacing the engine (~10k), which I will not be doing.
My second option is putting head gasket sealer in it, driving it around for as long as that lasts, and then selling this. I’m not super excited to do that, since I’d like to have faith in my 4runner like I always have. I need that peace of mind.
My third and favorite option is replacing the head gasket myself, which would allow me to also look at the head. It is the cheapest option by far, but I’m not convinced I could do something like that. I’d like to get some info on the difficulty of a job like that.
In closing, I think it would be stupid to give up on the engine or the car. It has 117000 miles, it has and an unbelievably little amount of rust. There is genuinely not a single speck of rust on the entire thing, and other than this issue, it is mechanically perfect. What should I do?
Also, I have tried absolutely everything to fix it, hoping it isn’t the head or head gasket, but it most likely is. It has never overheated, so it should be just the head gasket that needs replaced, or just the head that needs rebuilt.

 

^Are you the original owner? How diligently have you kept up with maintenance over the past 20 years? Trying to gauge the likelihood of oil sludge or blown transmission later on, which would ruin your "planned investment".

$10k sounds like a new engine. How much would it cost to replace with a lower-mileage salvage yard engine from say a 2015 Tacoma?

 

The 3rd option sounds like a winner. The 2nd option is like.. snake in the grass option. How nice is it to pass on a known problem to some unsuspecting buyer? Go with option 3.

 

I wouldn't pass it on without letting them know, but it might cost the same in resale value just to get it fixed. Not sure yet.

 

Are you the one that made the same thread back early August?
I think there were a few detailed videos on how to do it, the tear down including upper valve train in the head is the most difficult part in order to get the head off. Its not out of this world difficult, its just nuts and bolts.
The main cost is replacing all the reciprocal parts, all the things you gotta pull off. You gotta disassemble half the world to put a head gasket in that vehicle, and most any good mechanic is going to want you to also replace all those old parts, water pump, timing chain, guides, seals, gaskets, intake gaskets, ect ect ect. Sure, with only 117,000 you should still have a LOT of life left in a lotta parts and you "could" do the work yourself with only the necessary parts and likely be around $550.

The sealers are not going to fix what is wrong with yours, yours is missing the coating on the gasket, it has blown out which allows the water jacket to piss coolant into the cylinder. You are going to have leaks regardless of how much sealer you put in there. All you are going to do is gunk up the water pump and radiator.

 

If you want to replace gasket yourself due proper inspections first. There are kits to spot combustion gases in coolant and crankcase. Get a fiber optic inspection camera and take pics inside spark plug holes to look at cylinder walls and valves thru intake & exhaust manifolds.
When you have enough evidence to justify removing heads , have a machine shop inspect them for cracks and flatness. Rent or borrow a precision straight edge to inspect block for flatness.

 

I don't know your experience but I bought a 95 with a blown head gasket. I knew nothing about engines in general. Didn't even know how they worked. But with some youtube and some hours online learning how to rebuild an engine I did it. The head gasket job took longer then I thought between real life and motivation and I did some things wrong that I had to remedy but I did it. And now 2 years later I would say Im a pretty savvy mechanic having replaced ball joints, suspension, oil changes, starters, head gasket and everything to do with them. However my 95 engine is a lot more simple then the engine in yours and I was able to have this as a project not my daily. So it is possible if you have the time and desire.
I say do it, its a good learning experience and it is good knowledge to know. It sounds like a nice clean runner you got there. So best of luck. But just my opinion.