Dodge Repair: temperature gauge fluctuations

Question
2008 Dodge Grand Caravan 3.3 6 cylinder.  Is this car worth saving?  Past 3 months I have replaced intake gasket, put in new heater core, replaced thermostat, replaced radiator cap, and just this week had head gaskets replaced and head leak repaired.  Not losing any fluids right now that I see.  Overflow has not moved but I smell antifreeze and the temperature gauge fluctuates all the way to work.  I have heat and it has never overheated.  52 mile commute.  Had back from the shop 1 day.  What more can be wrong?

Answer
Hi Michelle,
When the cooling system is refilled from a fully drained condition there is likely to be some air trapped in it which will gradually be expelled via the overflow bottle. That air circulates through the system until it is totally exhausted. When a bubble of air passes through the thermostat housing the temperature sensor that is nearby 'sees' this as a cooling down of the system so the gauge drops and then rises again as the air moves on and is replaced by coolant.
So if you don't see any coolant on the engine or on the ground, nor do you have excessive smoke that smells of coolant coming from the tailpipe when you start the engine from cold, then the chances are that the system is water tight. The odor may be the air fumes coming from the overflow bottle. So keep an eye on the coolant level bottle and add 50/50 mixture when it shows 'low'. It may be that as the air is removed that the temp gauge will become steady.
Please read the PS below and respond to it.
Thanks,
Roland