Did the shop replace any of your coolant temp sensors? If you had oil in your coolant, which is unusual for a 104 engine, then the sensors get contaminated with gunk and don't give proper readings.
If that's the case, you may have had this problem all along, and not known it.
Regardless, I agree with the previous suggestions. Alter your coolant to water ratio down in favor of water; if nothing then replace T-stat; then try V-clutch; radiator being last resort.
Also check your belt tension to see if it is tight.