1995 Sunfire (2.2L auto)

Last night I was driving, and noticed that the car felt like it was missing.... I stop at a stop sign, and all of a sudden, white clouds of smoke start pouring out of the tailpipe and out from under the hood. The low coolant light comes on.

I stopped as soon as i could (about a half mile) and checked under the hood to see coolant spurting out right near where the exhaust header connects to the block (it was spurting right onto the header, which was causing the smoke under the hood)... my coolant tank was empty and the car sounds like it's running on two or three cylinders. The oil doesn't look milky, but seems rather thin and liquidy.

I turned it off and haven't started it again. I'm gonna say I'm 90% sure it's a head gasket problem, but i've never seen one spurt coolant out of the gap between the head and block...

Yes/No?

I would get it pressure tested. sounds like it could be spraying from your coolant tube as well, those tend to rot out.

Could be lots of things, I would definitely have it pressure tested to see before assuming head gasket.

Considering it was coming out of the tailpipe, and it's running roughly, I would definitely guess that coolant is making its way into at least one cylinder. Hopefully the head hasn't cracked. At my previous job (10 years ago) we had a fleet of S10/Sonomas with 2.2s, and almost all of our 1994 and 1995s developed cracks in the heads - usually above the #3 spark plug.

I wouldn't try starting the engine as it is. If coolant has filled one of the cylinders, it may cause the engine to hydrolock if you try to turn it over. You don't want to end up bending a rod or something - and since coolant has most likely made its way into the oil by now, you don't want to circulate more of that through everything than absolutely necessary. That can take out bearings pretty quickly.

Hopefully it's just the head gasket. Just make sure the head looks okay before bothering to re-assemble everything (assuming you find that the gasket is shot). I would also recommend getting a new set of head bolts for the job. The ones in there now have already been stretched, and could break if re-used. Maybe not mandatory, but highly recommended. A simple cooling system pressure test should make it pretty obvious where the problem lies. I would remove the plugs first - so that if the coolant is filling up one cylinder, it can get out rather than being forced into the oil.

Good luck!
John