No heat at idle
 

I know to bleed the system and have been doing so for the last 3 months about twice a month. I get heat at idle to return then after about 2 weeks its cold at idle again. It has to be getting air back into it somewhere. However i can't find any fluid leaking from any fitting that has to do with the cooling system. You'd think if I'm getting air into it again after a bleed off then fluid would be present at that spot.

I'm at a loss of where it could be coming from. Ive checked upper and lower hoses and the heater core hose. My carpet isnt went so no small leak from the core than I can tell. However I haven't visually looked at the core itself. If anyone has any ideas or had the same issue and fixed it please tell me what was wrong in your situation. I'm sick of burping this car every other week.

Rent a pressure tester.

idk why I haven't thought of that yet but will definitely do that.

Yeah it's an often overlooked tool but definitely the best way to troubleshoot those sort of issues.

Looks like the fsm says it should hold 23 psi? Last page

Make sure the hose from the radiator filler neck, just below the radiator cap is properly connected and has no cracks. As the coolant expands it pushes out from the radiator cap into the coolant reservoir. As the engine cools down, coolant gets sucked back into the radiator from the reservoir, so if the hose has a leak, air instead of coolant gets sucked into the radiator. If the hose is OK, check or replace the radiator cap.