This is classic symptom of an intake manifold gasket leak. Almost 100% failure rate on GM 3.1 and 3.4 engines. The coolant either leaks into the crankcase or is burned in the cylinders. Either way, if you don't get it fixed immediately, you'll destroy the engine. Plus, if you drive much longer the coolant will destroy the catalytic converter as well. Read this article

http://ricksfreeautorepairadvice.com/dex...

It's possible that you may be having a head gasket issue. Do you notice white smoke coming out of the exhaust a lot? smell antifreeze in the exhaust gas? Does it run hotter than normal/Overheat?

It can leak externally as well as internally.Depending on how long the coolant has been leaking,it could be mixed in the oil.Remove your oil dipstick and check oil.If the oil level is higher than it should be on the dipstick and/or if you notice a white milky substance mixed in the oil,you have a internal leak.Its most likely either the lower intake gasket or a blown head gasket.Besides the hoses,the radiator could be leaking,the water pump could be leaking out of the weep hole or at the gasket,leaking thermostat housing,or a leaking heater core.Check the passenger side floorboard to see if it feels wet.If it does,the heater core is leaking.Check the radiator cap seal for leaks too.A common known location for leaks to be hidden is on the backside or bottom side of coolant reservoir.It can get a small crack in it that's hard to see.

Its not acually running hot, the gauge is between the cold and hot. Thre isnt white smoke.