Jakez

Girlfriends 4runner slowly kept burning coolant (smoke) out the exhaust until one day it just bombed the entire town on the way to the store and back with smoke for about an hour it looked like a war zone. Now when she tries to run it it literally pours liquid coolant out of what I believe is a small drainage hole for condensation at muffler She ran a couple researched head gasket leak products through the radiator with not much luck. It actually starts and runs fine besides the burning and leaking coolant from the exhaust.

Seems like it's obviously blown headgasket(s) from my limited knowledge, but could it be anything other than headgaskets?

87-4runner

For coolant to get in the exhaust system it has to go thru the cylinders... they can hydro lock...
stop driving it... head gasket, cracked head, cracked block...

scope103

I'm pretty sure it's possible to get a crack in the head from the coolant passage directly to the exhaust-side of the exhaust valve. So it would run, and set up it's own smoke screen. But this is NOT good news. You'll need to remove the head (sooner rather than later), and I would surely have it pressure tested. If it passes, you'll be putting on a new head gasket on the way back and that should take care of it.

I know you were near-desperate, but try to stay away from anything like a "head gasket leak product." You know that it's basically glue that you hope will plug a leak. Now you've got a cooling system full of glue.

Jakez

I have a theory - I think the gasket fix stuff she used the first time clogged up the heater core (well, I know it did) trying to fix whatever the problem was, so any ("better") gasket fix stuff she used afterward wasn't able to do anything because the coolant hasn't been able to flow because of the clogged heater core. If she ran something through to unclog it and remove all the gasket fix stuff and then ran the gasket fix again - but this time bypassing the heater core so it doesn't clog up - perhaps it just might work?

I realize all of this isn't the right thing to do in the long run, but she basically feels like she isn't going to get anything ($$) out of it not being able to drive as is, and feels that paying hella $$ to have it fixed is money down the drain or not worth it, so the gasket fix stuff is like a what-the-hell-why-not... if anything I have offered to attempt doing the head gaskets myself if all else fails, although the only one I have ever done is on my 22re pickup (success!) and the amount of ˟˟˟˟ in her engine bay makes me want to cry lol..