air in coolant?

finally my car is almost working perfect.... i just had the head assembly replaced, this in conjunction with properly programming the tps i had to replace a while ago, has almost eliminated my idle fluctuation as well as slow dropping of the revs. however every now and then the idle still fluctuates and the rpms will drop slow. i have spoken with several people and have come to the conclusion that either omni-power sent me a bunk ass tps or, the other possible thing is that when i installed the new tps, i did get some air bubbles in the coolant lines from removing and reinstalling the throttle body. apparently there is some shraeder type valve on one of the coolant lines that can be used to release any air bubbles in the coolant lines....is this true, and if so has anyone located it because i have been working on finding it for a while...
oh and on a side note some fucker who replaced the rear bumper before i owned the car did not install the tail lights correctly and therefore, yesterday after it rained for the past 3 days, i had 2+ gallons of water in my spare compartment (at least 2 inches) so i have now had to remove all the carpet and such to stop the mold from stinking my car up. fuck cheap body work.