air bubble in the coolant line
 

anybody know how to get rid of an air bubble in the coolant line without flushing the whole system?

i heard that i can take the radiator cap off and let the car idle. does that work?

I dunno about not getting it flushed man. Try what ever comes to hand but a radiator flush never hurts.

Take the cap off the radiator, wrap the mouth w/ lots of paper towell (make like a bowl around it), and start the engine.
On startup have someone or you watch it ...the coolant will 'burp' and the air should be cleared. After a few mins just shut it down and then just refill via the reservoir.

You can do this a few times, but usually once should be enough. If that doesnt help then youre going to have to try something else. (it always works for me)

how do they get in there anyway??

filling the radiator too quickly usually is the culprit

I just let my car run with the rad cap off for a while when starting it up cold.
any air...got burped up.