Blown head gasket, should I swap engines or... ?

OK, I just checked into the cheap hotel right across the street from Gasket Masters in Manteca. I'm glad my wife isn't with me to note how old and mediocre this place is, but it'll be fine for a night. I'll roll the car across the street for them to work their incredibly fast (and hopefully good) magic first thing in the morning.

The car had been sitting in the garage for almost two weeks before I drove it today, and I listened carefully as it started - very smooth, no misfire! But it did rattle/knock several times at stoplights and some stop-and-go traffic in the first 15 minutes before I got going on the freeway. The coolant reservoir was an inch below the L mark this morning; I'd noticed it dropping slowly since I'd done some work in June, but not that low. I filled it up to almost running out the overflow before I left, and just checked again - it dropped more than an inch during the drive here. Otherwise it performed exactly as usual, reminding me how much I like this car. It's nice to have it here with no further damage - driving 350 miles on a blown head gasket today felt like rolling the dice a bit.

I'll make a new thread when I get home with my report on the work, since this chapter where I figure out what to do is ending tonight. Thanks everyone for your input, I would literally not be here in Manteca without you!

 

I got the head gasket changed at Gasket Masters, drove home, and everything has been good over a few trips in the few days since then. Thanks everyone here for your wisdom and input!

I made a new thread with the story, and to see what I should do next:
Gasket Masters replaced my HG - next steps? | PriusChat

@Tideland Prius probably time to lock this one, thanks!

 

The EGR system was on the list of items done, I asked and they said "Oh it's part of the normal thing we do, but yours was the cleanest we'd seen so we put it back as is" because I had thoroughly cleaned it a few thousand miles earlier. Other than that, no water pump, thermostat, or fuel injectors. This place seems to do two jobs only: head gasket and engine swap for Priuses. Read my report in the linked followup thread for more info on them. They offer a 1 year, unlimited mileage warranty on the head gasket only, which excludes obvious overheating or running out of oil.

I cleaned the fuel injectors a few months ago, they all seemed perfectly clean already. I'm thinking about the water pump and thermostat, which is why I started the new thread for my next steps.