wow. i hate when problems should be easy like 'replace the t-stat' but then nothing helps.
yes, it is possible to block coolant flow running around. i mean, really anything is possible in the realm of how dumb people can be sometimes. he could have left a banana or sandwich in the head for all we know. i've heard of stranger things happening.
sorry, this isn't helping.
yes, it is possible to block the flow of coolant through the block.
it is completely within the realm of possibility that such a thing has occured, though nothing else has fixed it so i don't know.
i'd take it back and raise hell until they redid the work, or figure out what was done to it.
