Chevrolet: Overheating ( 0303 Sensor ), chevy venture, head gasket

Question
I have a Chevy Venture 2001.  A few months ago I had a head gasket done.  The same day taking out the van  the service engine light appeared on/off.  The mechanic reset the system & it was gone.  Months later, it reappeared along with other problems. My dial was going close to overheat & when going up a hill, the car would hesitate on power before picking up speed.  Per the mechanic, my anti-freeze has clogged up badly in the radiator & cause sensor 0303 misfire.  Does this happens with all chevy (venture)? Should I get rid of the van?

Answer
It doesn't happen with all chevy ventures but I think when the mechanic did your head gasket he was too lazy to drain out all of the coolant and add new coolant resulting in crap from the head gasket swap clogging up the passageways.

I would sell it and gett another van before the next big repair.