air in cooling system

Anyone know how to get out air in cooling system. This is the second time it has done this to me know, although i geuss it was my fault this time. This is not the only problem though. In stop and go traffic it gets up to like 200 or so then if i get on the highway it will cool down to lke 150. Does that sound like a junk thermostat or not?

I've been having problems with it since the new motor install. I have the steeda rad and trickflow trackheat intake with a 1 inch spacer in it.any help will be greatly appreciated thank you.
 
Heating up to 200 in traffic is normal, but cooling down to 150 is not. You may want to check that stat. Remember though, a car will always heat up in traffic when air isn't going through the radiator. However the temp shouldn't get over 215 or so b/c the fan should cool it back down.