Head gasket failure has several different modes depending on where the gasket is breached. One mode is that coolant gets into the engine oil and turns it all into what looks like a gross melted chocolate milkshake. Another mode is the coolant gets blowed out the exhaust by the quart, which means you go down the road overheating with a huge rooster tail plume of steam coming out your tailpipe. And sometimes you just get constant overheating and coolant loss with no clear idea of where the fuck it's all going--I think Subarus are the champs of this failure mode.
And I hear you about not wanting to go deal with a new car--I felt the same way last year when Agnes booted her transmission and I spent more than I should have trying to get a new/used tranny bolted on her but it never did get done and I ended up having her hauled off anyway. Now I have a new/old Subaru Legacy and I'm pretty happy about this new Agnes. Sometimes it's just time, y'know?
