I have a 96 S-10 Blazer LT. I just bought it this past May. They did a coolant flush on it and some other stuff before I picked it up. A few months ago when the weather started to get cooler and I needed some heat, it didn't get to hot. I checked the coolant level and it was down some. I wasn't sure when the thermostat what changed last so I replaced it and filled it back up with coolant. I also put on a new radiator cap and overflow bottle cap. Since I done this stuff the heat has gotten better but it's just enough heat to keep me warm when the outside temp is in the low 40's but that's with the blower on high the whole time while I'm driving. I checked the heater core hoses and they are both hot when the engine is hot. I thought that their might still be some air in the system because sometimes I can still hear a girgeling noise coming from the dash. When I first got the blazer it was really making the nosie but now I can hardly hear it.
Also I plan on checking the coolant level in the morning to make sure it's still full. Haven't checked it in a while..
Do you think their is still air in the system or could it be the heater core or something else?
Thanks