Where you have air you dont have coolant. This means your heater wont work but more importanly, the block/head are not being cooled. Result: blown HG and maybe warped head. The whole point of a stat is to warm the engine up to operating temp as soon as possible so why would you want to put a hole in it? It take me about 20 minutes to bleed mine. If I am not happy I just leave it overnight and top up in the morning. No drilling holes, jacking the front up or fingers crossed behind my back
Oct '00 E46 330i. Feb '92 525i (departed)