I appriciate all the help guys, this is great stuff. I'm gonna go home tonight and do a quick cylinder pressure test and examine more closely for bubbles. If that turns up nothing, I'll see about finding a leakdown guage.



Quote
If your radiator fluid smells like that nasty burnt rag then you might verywell have a blown head gasket/cracked head..........


there is no decernable smell. the fluid itself appears (and smells) normal.

Quote
It's normal for coolant to enter the expansion tank whilst engine reaches normal op temp, and to be slurped back in as it cools.


Well, the problem is, what is puked out into the overflow never gets sucked back in. leaving the radiator significantly empty.

Quote
Half the rad's contents sounds extreme, how much did you actually add?


dumped the entire contents of the overflow back into the radiator plus about a liter of additional water.


-Rob