thermostat?

[Danton J.A. Cardoso]

OK, I have a coolant temperature gauge issue.  Car is a 98 A4 with a 2.8 30
valve.  The temperature gauge is buried at cold, however in stop/go it will
move up eventually to normal.  This past summer (first one with the car), it
went to normal and no overheating.  I get heat without a problem.  Sender
was replaced, could it be the thermostat?  How difficult?

Thanks

-- 
Danton J.A. Cardoso