Engine ran cold, now runs hot

[benebob]

Well at least that's what it says on the temp gauge. Was running around 1/8th to a 1/4. Took a while to register too. For the past 65k it has always run at a rock steady 1/3 on the gauge. Replaced the water pump, t-stat, front seals and t-belt. Still was running at the 1/8 to an 1/4. Took it out and cleaned it, no change. Swapped out the gauge temp sensor (the one wire top one) with one from an engine that's lying around here. Now it runs nearly dead center on the gauge (middle of the thermometer on the gauge). Only trouble codes are a flash for the coolant temp sensor when I swapped 'em and cleaned it out. Cleared it and it went away. Any ideas out there?

Oh and the engine feels about the same, fans come on about the same as before etc so I'm thinking it is a gauge reading issue.