bubbling coolant in overflow?
 

i have an '03 LS and after my engine is warm and i turn off ignition ive been noticing that its been making a gurgling noise. Today i noticed my overflow tank was bubbling. Not boiling bubbling but like a lot of air was coming up. since this started i have noticed that my running temp hasn't been getting as high has it used to. Was always at the halfway mark on the gauge now only a quarter of the way up? Just wondering if these are related and where to start in fixing the issue. Any words of wisdom related would be great! thanks everyone

Are you loosing any coolant? It should only bubble when drawing in more coolant to the radiator due to a leak. As far as the temp thing you thermostat us probably sticking open so its time to change it

well i bought the car in june and since then the coolant level has stayed the same. Haven't noticed any leaks anywhere. No spots on the ground nor under the hood, everything has looked pretty dry. I did read somewhere it could be because of air pressure trapped in the radiator and i should do a coolant flush but i dont want to go that route if i don't have to. I wanna see if anyone has had this issue and what they did. I also have the hard shift issue when engine is warm but i don't believe these issues are connected, but i could be wrong. I'll be ordering a thermostat today. thanks for replying

Actually air might be your whole problem, all though it would have to get in from somewhere. For now you can try bleeding it and see if you have heat, although its a good idea to change your t-stat to. Weather you have the 3.4 or 3.1 you should have 2 bleeder screws, 1 on top of the water pump and 1 on the thermostat housing. Warm the car up for several minutes or take it for a drive. Then open the bleeders (just a few turns, till coolant comes out), which should be 7mm bolts. Leave them open until you have a stream of coolant coming from them and no air

ill give that a shot. thanks again